identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
03BF2F39FF9865357066BEC18EF5F966.text	03BF2F39FF9865357066BEC18EF5F966.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Nautilida Agassiz 1847	<div><p>Order Nautilida Agassiz, 1847</p><p>Diagnosis</p><p>Exogastrically curved or coiled nautiloids with a conch shape ranging from gyroconic or cyrtoconic to more or less tightly coiled. Shell surface smooth or sculptured with a variety of elements (ribs, nodes, spines, longitudinal ridges or lines). Septa simply domed in most species, with the shape of the whorl profile producing suture lines with variable lobes and saddles. Variations in septal shape with inflexions producing deep lobes in some genera. Septal necks short and straight, rarely slightly widened. Connective rings cylindrical or beaded. Siphuncular or cameral deposits absent. Juvenile conch with cup-shaped initial chamber and narrow siphuncle. Morphological evolution includes the degree of coiling, the shape and size of the juvenile and adult conch and the suture line (after Shimansky 1962; emended).</p><p>Included suborders</p><p>Nautilina Agassiz, 1847 (Late Triassic to Recent).</p><p>Solenochilina Flower, 1950 (Early Carboniferous to Late Permian; 16 genera, 77 species).</p><p>Liroceratina Flower, 1955 (Early Carboniferous to Late Triassic; 26 Palaeozoic genera, 168 Palaeozoic species). Rutoceratina Flower, 1950 (Early to Middle Devonian).</p><p>Tainoceratina Shimansky, 1957 (Early Carboniferous to Triassic; 55 Palaeozoic genera, 279 Palaeozoic species). Temnocheilina Flower, 1963 (Late Devonian to Early Permian; 31 genera, 166 species).</p><p>Domatoceratina subordo nov. (Early Carboniferous to Triassic; 40 Palaeozoic genera, 201 Palaeozoic species).</p><p>Remarks</p><p>Shimansky (1962: 115; translated from Russian) characterised the order Nautilida as follows: “Conch nautiliconic, less often gyroceraconic, cyrtoceraconic or trochoceraconic, smooth or sculptured. Suture line variable in structure, often with distinct lobes and saddles, which are usually shallow but sometimes very deep. Septal neck straight, less often slightly widened, as a rule short. Connecting rings from cylindrical to beaded. Siphonal deposits and substantial cameral deposits absent. Embryonic shell with a cuplike initial chamber and a narrow siphuncle which is closed at the base. Development involves mainly the degree of coiling, the form and size of the embryonic and adult shell, and suture line.” (translation in Shimansky 1974)</p><p>Kummel (1964: K412) gave the following short statement: “Curved to coiled conchs presenting majority of mid-Paleozoic nautiloids. [ Tainocerataceae and Trigonocerataceae derived directly or indirectly from Oncocerida; origin of Clydonautilaceae and Aipocerataceae uncertain, probably from Rutoceratidae . Nautilidae stem from Syringonautilidae .]”</p><p>Dzik (1984: 149) also gave a short diagnosis: “Exogastrically coiled, moderately elongated shell with narrow, originally subcentral siphuncle (but ventral in Cenoceras, and dorsal in Aturia); larval development with an egg capsule, without planktonic larval stage.”</p></div>	https://treatment.plazi.org/id/03BF2F39FF9865357066BEC18EF5F966	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FF9865297036B84A8E25F862.text	03BF2F39FF9865297036B84A8E25F862.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Temnocheilina Flower 1963	<div><p>Suborder Temnocheilina Flower, 1963</p><p>Diagnosis</p><p>Suborder of the order Nautilida, in which a ventrolateral shoulder is formed early in ontogeny; advanced species may regress this character. Conch gyroconic, advolute or tightly coiled; general shape usually discoidal, subevolute or evolute. Juvenile whorl profile depressed elliptical or bicarinate in the early species and more circular in the advanced species. Adult whorl profile rounded triangular, but also rounded trapezoidal or circular in the early species, showing minor modifications during evolution. Dorsal whorl zone very small, if present. Juvenile stage with longitudinal ridges or lines. Septa simply domed. Suture line depending on the whorl profile, with shallow lobes and low saddles. Siphuncle in central or subcentral position.</p><p>Included superfamilies</p><p>Trigonoceratoidea Hyatt, 1884 (Early Carboniferous to Early Permian; 29 genera, 149 species). Koninckioceratoidea Hyatt, 1900 (Early Carboniferous to Early Permian; 2 genera, 17 species).</p><p>Remarks</p><p>Taxonomy</p><p>The suborder Temnocheilina was named with some ambiguity, as Flower (1963) used two slightly different spellings. In the first case Flower (1963: 93) postulated: “It would seem that the Tainoceratidae represent a lineage derived from the Tetragonoceratidae; however, unpublished material suggests a close relationship between the Devonian Rutoceratidae and the nodose Temnocheilidae and the smoother whorled Koninckioceratidae . The last two families with possible derivatives are a lineage to which the name Temnochelina may be applied.” On the same page, he referred to the publication by Shimansky (1957): “ Shimansky (1957), though using only suborders in a too-comprehensive Nautilida, has suggested the addition of Tainoceratina, Solenochilina and Temnocheilina . It would seem that there is a possible advantage in recognizing Rutoceratina and Tainoceratina, though the writer would place the Koninckioceratidae and Temnocheilidae in the Temnochelina, and add Aipoceratina to replace Solenochilina, a taxonomic recognition of the isolated position of that family.”</p><p>These statements were not critically discussed by Shimansky (1967: 38; translated from Russian): “Almost simultaneously, Flower (1963), in his interesting work on the Permian cyrtocones … speaks in some detail about the families Temnocheilidae and Koninckioceratidae, indicates the likelihood of a common origin and suggests the name Temnocheilina for this group.” Later in the article (Shimansky 1967: 42; translated from Russian) he added: “Flower believes that the group can be considered as a suborder Temnocheilina, including the families Temnocheilidae and Koninckioceratidae .”</p><p>The problem here is that Flower (1963) apparently had no intention of defining a new suborder, and mistakenly assumed that Shimansky (1957) had already established the suborder. It is also not clear whether the name “Temnochelina” used twice was a typographical error; in the supposed reference to Shimansky (1957) he used “ Temnocheilina ”. However, it appears to be clear that Flower advocated a suborder Temnocheilina, albeit to a rather limited extent with the families Temnocheilidae and Koninckioceratidae . Furthermore, it may have been Flower’s intention to name the suborder Temnocheilina; therefore this name is used here.</p><p>Shimansky (1957, 1962) included the family Temnocheilidae Mojsisovics, 1902 in the suborder Tainoceratina, the families Triboloceratidae Hyatt, 1884, Thrincoceratidae Ruzhencev &amp; Shimansky, 1954 and Phacoceratidae Shimansky, 1962 in the suborder Centroceratina and the family Koninckioceratidae Hyatt, 1900 in the suborder Liroceratina . Later, Shimansky (1967, 1979) changed his opinion; the superfamilies Temnocheilaceae Mojsisovics, 1902, Koninckiocerataceae Hyatt, 1900 and Trigonocerataceae Hyatt, 1884 were placed in the suborder Rutoceratina .</p><p>Kummel (1964) placed the taxa of the suborder Temnocheilina as understood here in the superfamilies Tainocerataceae Hyatt, 1883 and Trigonocerataceae Hyatt, 1884 . Dzik (1984) recognised a closer relationship of genera such as Vestinautilus Ryckholt, 1852 and Temnocheilus M‘Coy, 1844 and placed these genera in the family Trigonoceratidae Hyatt, 1884 . From this he directly derived the family Phacoceratidae Shimansky, 1962 .</p><p>The concept of Dzik (1984) is followed here for the following reasons: the morphology of the initial whorl is similar in all species of the suborder, with a mostly broadly elliptical whorl profile and a sculpture of coarse longitudinal ridges. In many species a prominent ventrolateral shoulder developed from the lateral margin of the initial whorl. The ventrolateral row of nodes characteristic of Temnocheilus Mojsisovics, 1902 is not considered to be related to the nodes of members of the suborder Tainoceratina (e.g., Metacoceras Hyatt, 1883), but is considered to be an independent development. These nodes are not a continuation of the lateral ribs (as in Metacoceras) and are elongated longitudinally; rather, they may be related to the ventrolateral spiral ridges in genera such as Vestinautilus .</p><p>The concept of the suborder Temnocheilina presented here differs significantly from previously published concepts of comparable taxonomic groups. It contains the majority of the Tournaisian and Viséan coiled nautiloids, which were previously distributed in the suborders Tainoceratina, Centroceratina and Liroceratina (Shimansky 1957, 1962), the suborder Rutoceratina (Shimansky 1967), the superfamilies Tainocerataceae Hyatt, 1883 and Trigonocerataceae Hyatt, 1884 (Kummel 1964) or the family Trigonoceratidae Hyatt, 1884 (Dzik 1984).</p><p>Morphology and subdivision</p><p>The vast majority of species in the suborder Temnocheilina have a discoidal conch with a widely opened umbilicus. Especially in the stratigraphically older Tournaisian and Viséan species, there is a morphocline ranging from gyroconic, advolute to more or less tightly coiled conchs. The umbilical foramen is quite large in most of the species; it is usually more than 5 mm in diameter, but can be considerably larger. A common character of most early representatives is the triangular adult whorl profile, which is preserved in various variations throughout the phylogeny of the group. This shape evolved from an early ontogenetic depressed oval or bicarinate shape of the whorl profile, in which the initial lateral margin developed into the ventrolateral shoulder (Fig. 3A, F). In later species, the whorl profile of the early ontogenetic stage is usually circular. In the juvenile stage of the early species, the shell is decorated with coarse spiral ridges. These lines evolved in the different evolutionary lineages into either fine spiral ornament (e.g., Rineceras Hyatt, 1893) or very coarse ridges (e.g., Vestinautilus Ryckholt, 1852), which gave the whorl profile a polygonal shape. More advanced species usually had a pattern of finer spiral lines. Longitudinally elongated ventrolateral nodes are present in the family Temnocheilidae Mojsisovics, 1902 .</p><p>In this paper, the suborder Temnocheilina is redefined on the basis of a phylogenetic hypothesis based on the shape of the initial whorl and its modification during ontogeny. The suborder Temnocheilina contains the species with the most plesiomorphic characters of the Carboniferous and is the dominant suborder of the Early Carboniferous. The suborder Temnocheilina is divided into two superfamilies, which are characterised as follows:</p><p>Trigonoceratoidea Hyatt, 1884 . – The whorl profile in the ancestral species is often triangular or trapezoidal with a flat venter; derived species show various modifications leading to circular shapes. During ontogeny, the geometry of the conch changes slightly. The shell is usually ornamented with spiral ridges or spiral lines.</p><p>Koninckioceratoidea Hyatt, 1900 . – The whorl profile is depressed oval and does not change during ontogeny. The shell surface is largely smooth.</p><p>Origin</p><p>There are several concepts to explain the evolutionary pathways of curved and coiled nautiloids during the Devonian–Carboniferous transition and thus the origin of the taxa defined here as Temnocheilina . This group was partly named suborder Centroceratina and was interpreted by Shimansky (1957) to start with the Devonian family Centroceratidae Hyatt, 1900; according to this it had been derived from the family Rutoceratidae Hyatt, 1884 . At the end of the Triassic, the suborder Centroceratina gave rise to the suborder Nautilina, which includes all Jurassic to Recent coiled nautiloids.</p><p>According to the phylogenetic scheme outlined by Dzik (1984), all post-Devonian coiled nautiloids, with the exception of the aipoceratids, form a monophyletic unit with roots in the earliest Carboniferous.</p><p>Dzik &amp; Korn (1992) presented Dasbergoceras Dzik &amp; Korn, 1992 as a possible ancestor of the Trigonoceratidae and thus the suborder Temnocheilina and with this the majority of post-Devonian coiled nautiloids. Dasbergoceras alternans (Tietze, 1871) has an advolute conch with a large umbilical foramen (27 mm) and a trapezoidal whorl profile. It possesses coarse radial ribs terminating in prominent conical nodes on the ventrolateral shoulder. The siphuncle is located close to the venter. Although this species shows some superficial resemblance to species of Temnocheilus, it can hardly be considered a direct ancestor; Temnocheilus was probably derived from Subvestinautilus Turner, 1954, as suggested by Dzik &amp; Korn (1992: 88), and the ventrolateral row of nodes is considered a secondary character.</p><p>The ancestry of the Temnocheilina, with or without Dasbergoceras included, is an unsolved problem because of several unanswered questions:</p><p>(1) What was the morphological inventory of a possible ancestor of the Temnocheilina ? – The characters of the almost central siphuncle and the ornamentation with spiral ridges in the early juvenile stage, which are important for the Temnocheilina, are not present in the Devonian nautilids, including Dasbergoceras .</p><p>(2) Are the Temnocheilina derived from fully coiled or loosely coiled conchs? For example, does Trigonoceras M‘Coy, 1844 represent a plesiomorphic form or did the cyrtoconic conch arise by secondary uncoiling? – Intuition, based on knowledge of some other evolutionary lineages in cephalopods, would favour an evolutionary lineage from loosely coiled to fully coiled conchs. However, this observation in some of the groups may not apply in every individual case; some other cases of probable secondary uncoiling are known, for example in Maccoyoceras Miller, Dunbar &amp; Condra, 1933 where the terminal whorl separates slightly from the preceding one (Foord 1900; Histon 1999).</p><p>(3) Did the oldest representatives of the Temnocheilina undergo a rapid middle and late Tournaisian evolution after the Hangenberg Event at the Devonian–Carboniferous boundary, or was it a slow, long evolutionary process that started already in the Late Devonian, but was hidden without a fossil record? – The ‘nautiloid gap’ spanning most of the Late Devonian and the earliest Carboniferous with the only one known genus Dasbergoceras in the latest Devonian is the cardinal obstacle to answering this question. This is related to the general question of possible very different evolutionary rates in nautiloids.</p><p>Phylogeny</p><p>Gaps in our knowledge mean that the evolutionary pathways within the suborder Temnocheilina are, at least in part, unknown. Several questions concern the degree of involution of the conch, the shape of the whorl profile and the ornamentation:</p><p>(1) Do the gyroconic conchs (e.g., Trigonoceras M‘Coy, 1844) represent the plesiomorphic state or are they the result of secondary uncoiling? – This is a difficult question to answer as there are only very fragmentary records of the stratigraphically oldest representatives. Moreover, openly coiled conchs are known from both the oldest known assemblages such as Chouteauoceras Miller &amp; Garner, 1953 in early Late Tournaisian (Miller &amp; Furnish 1939; Miller &amp; Garner 1953) and from much younger assemblages such as Trigonoceras in the Viséan (Maillieux 1925). It is possible that both evolutionary paths, including increased coiling and also secondary uncoiling, were realised in these Early Carboniferous nautiloids. However, if a form like Dasbergoceras was the ancestor, then repeated cases of secondary uncoiling must be assumed.</p><p>(2) Does the triangular (e.g., Trigonoceras M‘Coy, 1844, Triboloceras Hyatt, 1884), compressed oval ( Chouteauoceras), or depressed ovate (e.g., Rineceras Hyatt, 1893) whorl profile represent the plesiomorphic condition? – Similar to the general conch shape, the evolutionary pathways of the whorl profile are also not fully understood. For example, in the proposed evolutionary lineage Triboloceras - Vestinautilus - Subvestinautilus, an evolutionary trend can be observed from angular triangular to more rounded triangular and trapezoidal whorl profiles.</p><p>(3) Are coarse longitudinal ridges or more delicate spiral lines of the juvenile conch the plesiomorphic state? – Longitudinal ridges in the stratigraphically oldest known species have been reported from several Middle and early Late Tournaisian formations, including the Calcaire de Vaulx and Calonne in Belgium (de Koninck 1878), the Chouteau Formation in Missouri (Miller &amp; Furnish 1939), the Marshall Sandstone in Michigan (Miller &amp; Garner 1953) and the Argiles de Teguentour in central Algeria (Korn &amp; Bockwinkel 2022). At the same time, the coarse spiral ornamentation of the earliest juvenile stage has been reported to have regressed in several species and genera. These records provide good evidence for the hypothesis that the longitudinal ridges represented a plesiomorphic state. In addition, the stratigraphic position of the material also suggests that in one derived evolutionary lineage (family Subclymeniidae Shimansky, 1962 of the suborder Domatoceratina subordo nov.) there was a phylogenetic change in the juvenile ornamentation from coarse spiral ridges (early Late Tournaisian) to fine spiral lines (latest Tournaisian) and finally to the loss of spiral ornamentation (Viséan). In others, the spiral ridges were reduced in number but became much coarser (family Epistroboceratidae fam. nov. of the suborder Domatoceratina) or were gradually reduced (e.g., Vestinautilinae subfam. nov. and Temnocheilidae Mojsisovics, 1902).</p><p>Despite these partly unresolved problems, at least some possible phylogenetic lineages can be identified, which are also supported by stratigraphic data. A morphological transformation of the different conch characters can be observed:</p><p>(1) General coiling. – Within the genera Rineceras and Vestinautilus there is an evolutionary trend towards increasingly dense coiling, which could be seen as a general trend among the early representatives of the Temnocheilina .</p><p>(2) Whorl profile. – There is a trend from triangular to rounded trapezoidal shapes. This is related to the tighter enclosure of the preceding whorls. However, there is also a trend from an originally concave or at least strongly flattened venter to an increasingly convex rounded venter.</p><p>(3) Sculpture. – A general trend can be seen in the decreasing strength of the spiral ridges. Such a trend affects, for example, the number and strength of spiral ridges, as can be seen in Vestinautilus and Subvestinautilus .</p><p>Descendants</p><p>According to the current state of knowledge, three further suborders can be derived from the Temnocheilina; these are the Domatoceratina subordo nov., the Tainoceratina and the Liroceratina . The first two are distinguished from the Temnocheilina by the more or less simultaneous early ontogenetic formation of an umbilical margin and a ventrolateral shoulder; the latter developed only an umbilical margin but no prominent ventrolateral shoulder. The demarcation of some of the genera (e.g., Catastroboceras Turner, 1965 and Epidomatoceras Turner, 1954) placed here in the Domatoceratina is sometimes difficult because it is not always clear whether they already possess an umbilical margin. However, this is formed by the reduction of the spiral ridges present in the early growth stage. The early ontogenetic stage of Tainoceratina, at least those from the Early Permian, apparently does not show a spiral ornament (Ruzhencev &amp; Shimansky 1954).</p></div>	https://treatment.plazi.org/id/03BF2F39FF9865297036B84A8E25F862	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FF85652B7017BE69897EFAEA.text	03BF2F39FF85652B7017BE69897EFAEA.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Nautilida Hyatt 1884	<div><p>Superfamily Trigonoceratoidea Hyatt, 1884</p><p>Figs 6–10</p><p>Diagnosis</p><p>Superfamily of the suborder Temnocheilina, in which a ventrolateral shoulder is formed early in ontogeny. Conch gyroconic or advolute in some species, but more or less tightly coiled in most of the species; general conch form usually discoidal, subevolute or evolute. Whorl profile depressed elliptical or bicarinate in the initial growth stage of the early species and circular in the advanced species. Conch ontogeny with the widest area of the initial growth stage transforming into a pronounced ventrolateral shoulder. Adult whorl profile often rounded triangular but also rounded trapezoidal, polygonal or circular. Juvenile stage with longitudinal ridges or lines, which are particularly pronounced in the area of the venter and the ventrolateral shoulder of the adult stage. Septa simply domed. Suture line with shallow lobes and saddles; internal lobe absent or very shallow and rarely triangular.</p><p>Included families</p><p>Trigonoceratidae Hyatt, 1884 (Early Carboniferous to Early Permian; 13 genera, 72 species).</p><p>Triboloceratidae Hyatt, 1884 [synonym of Trigonoceratidae].</p><p>Rineceratidae Hyatt, 1893 [synonym of Trigonoceratidae].</p><p>Rhineceratidae Hyatt, 1900 [nomen nullum, synonym of Trigonoceratidae].</p><p>Temnocheilidae Mojsisovics, 1902 (Early Carboniferous to Early Permian; 11 genera, 59 species).</p><p>Thrincoceratidae Ruzhencev &amp; Shimansky, 1954 (Early Carboniferous to Early Permian; 4 genera, 17 species).</p><p>Knightoceratidae Shimansky, 1962 [synonym of Temnocheilidae].</p><p>Neothrincoceratidae Shimansky, 1962 [synonym of Thrincoceratidae].</p><p>Dasbergoceratidae fam. nov. (Late Devonian; 1 genus, 1 species).</p><p>Remarks</p><p>The superfamily Trigonoceratoidea probably originated in a genus similar to Dasbergoceras in the latest Famennian (Late Devonian). Along with the superfamily Aipoceratoidea, it is the second evolutionary lineage of coiled nautiloids to cross the Devonian-Carboniferous boundary (Dzik &amp; Korn 1992). There are as yet no records from the earliest Carboniferous period, the Gattendorfia Stufe in the traditional ammonoid stratigraphy. On the basis of current knowledge, it is likely that coiled nautiloids underwent rapid morphological evolution during the Middle Tournaisian, which may be the reason for the great conch and sculpture diversity in the Late Tournaisian.</p><p>The adult conch shapes of the Trigonoceratoidea are diverse, ranging from cyrtoconic to subevolute; the latter being the dominant ones (Fig. 6). This is the reason why it is difficult to characterise the superfamily on the basis of the adult conch shape alone. The same is true for the ornamentation. In many species, there are more or less pronounced spiral ridges or spiral lines developed, but this can also be reduced in many advanced species. The course of the suture line is usually strongly dependent on the shape of the whorl profile. This is because the septum is usually uniformly concave in shape. For this reason, the ontogeny of conch shape and ornamentation is used here as a key character to distinguish families and subfamilies.</p><p>Four families within the Trigonoceratoidea can be separated on the base of the following principal characters:</p><p>Dasbergoceratidae fam. nov. – Ancestral taxa with a triangular whorl profile and a large umbilical foramen. Sculpture with short radial ribs ending in conical ventrolateral nodes. Siphuncle subcentral, close to the venter (Fig. 7).</p><p>Trigonoceratidae . – Ancestral taxa with a wide variety of conch shapes ranging from cyrtoconic to more or less tightly coiled. Early juvenile whorl profile depressed oval. Internal lobe shallow, broadly rounded (Fig. 8).</p><p>Thrincoceratidae . – Derived taxa with a usually evolute conch shape. Early juvenile whorl profile nearly circular. Internal lobe shallow, broadly rounded (Fig. 9).</p><p>Temnocheilidae . – Derived taxa with a subevolute or evolute conch shape. Early juvenile whorl profile strongly depressed oval. Internal lobe deep, funnel-shaped or subtriangular (Fig. 10).</p><p>The superfamily Trigonoceratoidea differs from the superfamily Koninckioceratoidea in the shape of the whorl profile, which is triangular or trapezoidal with a flat venter in the ancestral Trigonoceratoidea, but simply oval in the Koninckioceratoidea . In addition, the shell of the Trigonoceratoidea is decorated with coarse, long ridges, whereas that of the Koninckioceratoidea is almost smooth.</p></div>	https://treatment.plazi.org/id/03BF2F39FF85652B7017BE69897EFAEA	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FF81652C7038BE698FFDFB4A.text	03BF2F39FF81652C7038BE698FFDFB4A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Dasbergoceratidae Korn 2025	<div><p>Family Dasbergoceratidae fam. nov.</p><p>urn:lsid:zoobank.org:act: D31465BD-72EB-43EE-B36E-4B9DEF64B0C3</p><p>Fig. 7</p><p>Type genus</p><p>Dasbergoceras Dzik &amp; Korn, 1992 .</p><p>Diagnosis</p><p>Family of the superfamily Trigonoceratoidea with a subevolute conch with very small whorl overlap; large umbilical foramen. Whorl profile in the adult stage rounded trapezoidal and depressed oval in the early juvenile stage. Ornament with transverse ribs. Position of the siphuncle closer to the venter than to the centre. Suture line with broadly rounded shallow lobes and low saddles.</p><p>Etymology</p><p>The family name refers to the type genus.</p><p>Included genus</p><p>Dasbergoceras Dzik &amp; Korn, 1992 (Famennian; 1 species).</p><p>Remarks</p><p>Dzik &amp; Korn (1992) devoted a separate paper to the genus Dasbergoceras (Fig. 7), discussing the importance of this Late Devonian genus as a link between Devonian and Carboniferous curved and coiled nautiloids. Apparently, no other material has been described since. Therefore, the question of whether Dasbergoceras is a direct ancestor of the Carboniferous Trigonoceratoidea or whether it is a side branch of the Trigonoceratoidea cannot be answered unequivocally. Dasbergoceras has morphological peculiarities that distinguish it from all other genera of the Trigonoceratoidea . These include the subventrally located siphuncle and the radial ribbing. For this reason, an independent family Dasbergoceratidae fam. nov. is proposed here.</p></div>	https://treatment.plazi.org/id/03BF2F39FF81652C7038BE698FFDFB4A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FF81652F703DBB9D8ECFFE17.text	03BF2F39FF81652F703DBB9D8ECFFE17.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Trigonoceratidae Hyatt 1884	<div><p>Family Trigonoceratidae Hyatt, 1884</p><p>Diagnosis</p><p>Family of the superfamily Trigonoceratoidea with cyrtoconic to subevolute conch with small whorl overlap if present; large or moderately large umbilical foramen. Whorl profile in the adult stage commonly ranging from triangular to depressed oval, rarely compressed oval or polygonal. Whorl profile usually depressed oval in the early juvenile stage. Ornament with longitudinal ridges or lines, rarely transverse ribs; sometimes the conch is smooth. Position of the siphuncle closer to the centre than to the ventral side. Suture line with broadly rounded shallow lobes and low saddles.</p><p>Included subfamilies</p><p>Trigonoceratinae Hyatt, 1884 (Early Carboniferous to Early Permian; 7 genera, 38 species). Chouteauoceratinae subfam. nov. (Early Carboniferous to? Early Permian; 3 genera, 5 species). Vestinautilinae subfam. nov. (Early Carboniferous; 3 genera, 29 species).</p><p>Remarks</p><p>Flower &amp; Kummel (1950: 615) combined the families Triboloceratidae, Trigonoceratidae and Rineceratidae of Hyatt and gave priority to the first of these. Following the idea of Shimansky (1962), the family Trigonoceratidae is divided into several subfamilies here, which differ in the following morphological characteristics:</p><p>Trigonoceratinae . – Whorl profile triangular, sculpture with very coarse longitudinal ridges (Fig. 11). Chouteauoceratinae subfam. nov. – Whorl profile compressed oval, sculpture with numerous longitudinal ridges of the same strength (Fig. 12).</p><p>Vestinautilinae subfam. nov. – Whorl profile rounded trigonal or rounded trapezoidal, sculpture with a few coarse longitudinal ridges, usually of different strength (Fig. 13).</p></div>	https://treatment.plazi.org/id/03BF2F39FF81652F703DBB9D8ECFFE17	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FF82652E7020BEBA89F2FC27.text	03BF2F39FF82652E7020BEBA89F2FC27.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Trigonoceratinae Hyatt 1884	<div><p>Subfamily Trigonoceratinae Hyatt, 1884</p><p>Fig. 11</p><p>Diagnosis</p><p>Subfamily of the family Trigonoceratidae with cyrtoconic to evolute or subevolute conch. Whorl overlap small if present. Whorl profile ranging from triangular to depressed oval. Venter flat or rounded. Sculpture in the early species with longitudinal, equidistant ridges throughout ontogeny; advanced species with reduction of spiral ridge number. Suture line with broadly rounded lobes and saddles.</p><p>Included genera</p><p>Trigonoceras M‘Coy, 1844 (Tournaisian to Viséan; 3 species).</p><p>Discites M‘Coy, 1844 [non Schlotheim, 1813, nec De Haan, 1825; synonym of Discitoceras]. Nautiloceras d’Orbigny, 1849 (Tournaisian; 1 species).</p><p>Triboloceras Hyatt, 1884 (Tournaisian to Viséan; 11 species).</p><p>Discitoceras Hyatt, 1884 (Tournaisian; 4 species).</p><p>Rineceras Hyatt, 1893 (Tournaisian to Viséan; 17 species).</p><p>Rhineceras Hyatt, 1900 [synonym of Rineceras].</p><p>Apogonoceras Ruzhencev &amp; Shimansky, 1954 (Artinskian; 1 species)?</p><p>Pararineceras Turner, 1954 [synonym of Rineceras].</p><p>Stroborineceras Korn &amp; Bockwinkel, 2022 (Tournaisian to Viséan; 4 species).</p><p>Remarks</p><p>The cardinal character of the representatives of the subfamily Trigonoceratidae seems to be the slightly depressed oval whorl profile in the early ontogenetic stage and the approximately equidistantly arranged spiral ridges, which are equally developed on the venter as well as on the flanks and dorsum.</p><p>The general conch shape is very variable, ranging from cyrtoconic ( Trigonoceras) to gyroconic ( Triboloceras) and advolute (some species of Triboloceras and Rineceras) to evolute (most species of Rineceras). Almost all species have a more or less triangular or trapezoidal whorl profile.</p></div>	https://treatment.plazi.org/id/03BF2F39FF82652E7020BEBA89F2FC27	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FF8365217009BC888F66FCEA.text	03BF2F39FF8365217009BC888F66FCEA.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chouteauoceratinae Korn 2025	<div><p>Subfamily Chouteauoceratinae subfam. nov.</p><p>urn:lsid:zoobank.org:act: F1BF14B1-72AD-460F-B4F5-5632817F4C03</p><p>Fig. 12</p><p>Type genus</p><p>Chouteauoceras Miller &amp; Garner, 1953</p><p>Diagnosis</p><p>Subfamily of the family Trigonoceratidae with cyrtoconic or gyroconic conch. Whorl profile compressed oval; venter rounded. Sculpture in the early species with longitudinal, equidistant ridges throughout ontogeny; advanced species with a reduction of spiral ridges. Suture line with broadly rounded lobes and saddles.</p><p>Etymology</p><p>The subfamily name refers to the type genus.</p><p>Included genera</p><p>Chouteauoceras Miller &amp; Garner, 1953 (Tournaisian; 3 species).</p><p>Ungeroceras Sturgeon &amp; Miller, 1948 (Moscovian; 1 species).</p><p>Parachouteauoceras Niko &amp; Ozawa, 1997 (Gzhelian or Asselian; 1 species).</p><p>Remarks</p><p>The subfamily Chouteauoceratinae subfam. nov. contains genera that are not very well known. It is therefore uncertain whether the other two genera, in addition to the typical genus Chouteauoceras, are members of this subfamily. This is particularly true for the enigmatic Late Carboniferous genus Ungeroceras, newly described by Sturgeon &amp; Miller (1948). This genus was synonymised by Murphy (1966) with the orthoconic genus Kionoceras Hyatt, 1884 . Sturgeon et al. (1997: 57) discussed the genus, concluding that it is probably a coiled nautiloid, possibly related to the stratigraphically older Tournaisian genus Chouteauoceras (Miller &amp; Garner 1953) . Loose coiling and a compressed whorl profile are accepted as the most important criteria (Fig. 12). However, further research and new material may substantiate this hypothesis.</p></div>	https://treatment.plazi.org/id/03BF2F39FF8365217009BC888F66FCEA	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FF8C65207028BCFC894BFC27.text	03BF2F39FF8C65207028BCFC894BFC27.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Vestinautilinae Korn 2025	<div><p>Subfamily Vestinautilinae subfam. nov.</p><p>urn:lsid:zoobank.org:act: 10F74235-B3AF-4D2A-A0B8-92DBA57676A4</p><p>Fig. 13</p><p>Type genus</p><p>Vestinautilus Ryckholt, 1852 .</p><p>Diagnosis</p><p>Subfamily of the family Trigonoceratidae with discoidal to pachyconic, subevolute conch. Whorl overlap small. Whorl profile usually rounded triangular or rounded trapezoidal. Venter broadly rounded, flattened or weakly concave. Ornament with longitudinal ridges in most species; younger species show a reduction of the spiral ridges. Suture line with rounded external and lateral lobes, internal lobe shallow.</p><p>Etymology</p><p>The subfamily name refers to the type genus.</p><p>Included genera</p><p>Vestinautilus Ryckholt, 1852 (Tournaisian to Viséan; 20 species).</p><p>Edaphoceras Hyatt, 1884 (Viséan; 2 species).</p><p>Subvestinautilus Turner, 1954 (Tournaisian to Viséan; 7 species).</p><p>Remarks</p><p>The Vestinautilinae subfam. nov. are a subfamily that can be easily distinguished from the other subfamilies by their characteristic morphology with a rounded triangular or rounded trapezoidal whorl profile and the presence of coarse longitudinal ridges (Fig. 13).</p><p>The origin of the Vestinautilinae subfam. nov. is probably to be found in the subfamily Trigonoceratinae . The stratigraphically oldest species of Vestinautilus from the early Late Tournaisian have a conch morphology and shell ornamentation that still closely resemble species from genera such as Triboloceras and Rineceras . The Vestinautilinae show a morphological evolution with a progressive reduction in the number of longitudinal ridges. These are largely restricted to the ventrolateral shoulder in the younger species. At the same time, the venter changes from a concave to a convex shape.</p></div>	https://treatment.plazi.org/id/03BF2F39FF8C65207028BCFC894BFC27	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FF8D652073C1BC8A8E25F863.text	03BF2F39FF8D652073C1BC8A8E25F863.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Thrincoceratidae Ruzhencev & Shimansky 1954	<div><p>Family Thrincoceratidae Ruzhencev &amp; Shimansky, 1954</p><p>Fig. 9</p><p>Diagnosis</p><p>Family of the superfamily Trigonoceratoidea with discoidal, subevolute to evolute conch; whorl overlap small if present, coiling rate high to extremely high. Whorl profile almost circular in the early juvenile stage. Ornament in the early species with longitudinal, equidistant ridges throughout ontogeny; advanced species with reduction of spiral lines. Suture line with broadly rounded lobes and saddles.</p><p>Included genera</p><p>Thrincoceras Hyatt, 1893 (Tournaisian to Viséan; 8 species).</p><p>Lispoceras Hyatt, 1893 (Tournaisian to Serpukhovian; 5 species).</p><p>Diodoceras Hyatt, 1900 (Tournaisian; 1 species).</p><p>Neothrincoceras Ruzhencev &amp; Shimansky, 1954 (Artinskian; 3 species).</p><p>Remarks</p><p>Ruzhencev &amp; Shimansky (1954) established the family Thrincoceratidae for the genera Thrincoceras, Maccoyoceras and Neothrincoceras and had “not the slightest doubt” that this family and the “closely related” family Domatoceratidae Miller &amp; Youngquist, 1949 descended from common ancestors, and not directly from each other (Ruzhencev &amp; Shimansky 1954: 51). A little later, Shimansky (1962) classified the group only as a subfamily with the genera Discitoceras, Stroboceras, Thrincoceras, Maccoyoceras and Epistroboceras Turner, 1954, while Neothrincoceras was placed in the family Neothrincoceratidae within the superfamily Centrocerataceae . Another five years later, Shimansky (1967: 168) reduced the subfamily to the genera Thrincoceras and Neothrincoceras .</p><p>Kummel (1964: K427) considered both the Thrincoceratidae and the Neothrincoceratidae to be synonyms of the Trigonoceratidae . Histon (1999) also included the genus Thrincoceras in the Trigonoceratidae . Dzik (1984: 172) included Thrincoceras, together with Discitoceras, Pararineceras and Maccoyoceras in Lispoceras within the family Trigonoceratidae .</p></div>	https://treatment.plazi.org/id/03BF2F39FF8D652073C1BC8A8E25F863	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FF8E6522701EBE698F58FC6D.text	03BF2F39FF8E6522701EBE698F58FC6D.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Temnocheilidae Mojsisovics 1902	<div><p>Family Temnocheilidae Mojsisovics, 1902</p><p>Fig. 10</p><p>Diagnosis</p><p>Family of the superfamily Trigonoceratoidea with subinvolute or subevolute conch; coiling rate usually very high. Whorl overlap small if present. Adult whorl profile commonly ranging from triangular to trapezoidal with weakly embracing whorls; juvenile whorl profile broadly oval or bicarinate. Ornament with longitudinal ridges or lines in the juvenile stage, adult conch with ventrolateral nodes, spiral ridges or smooth, sometimes with spiral ornament. Position of the siphuncle between centre and venter. Suture line with broadly rounded external and lateral lobes; internal lobe broadly V-shaped; sometimes with an annular process.</p><p>Included genera</p><p>Temnocheilus M‘Coy, 1844 (Viséan to Kasimovian; 10 species).</p><p>Endolobus Meek &amp; Worthen, 1865 (Viséan to? Roadian; 14 species).</p><p>Knightoceras Miller &amp; Owen, 1934 (Viséan to Artinskian; 9 species).</p><p>Tylodiscoceras Miller &amp; Collinson, 1950 (Serpukhovian; 2 species).</p><p>Valhallites Shimansky, 1954 (Viséan to? Artinskian; 8 species).</p><p>Nikenautilus Shimansky, 1962 (Serpukhovian; 2 species).</p><p>Kummeloceras Shimansky, 1967 (Artinskian; 1 species).</p><p>Temnocheiloides Shimansky, 1967 (Bashkirian to Moscovian; 2 species).</p><p>Latitemnocheilus Sturgeon, Windle, Mapes &amp; Hoare, 1982 (Serpukhovian to Asselian; 9 species). Paravalhallites Shimansky, 1990 (Bashkirian; 1 species).</p><p>Alexoceras Leonova &amp; Shchedukhin, 2020 (Asselian or Sakmarian; 1 species).</p><p>Remarks</p><p>The Temnocheilidae is a family that has been defined in various ways over the years. Originally, it was placed by Mojsisovics (1902: 230) as the fourth family within his higher taxon “ Nautilidae ” and contained a number of morphologically very different genera such as Temnocheilus M‘Coy, 1844, Metacoceras Hyatt 1883, Tainoceras Hyatt 1883, Foordiceras Hyatt, 1893, Pleuronautilus Hyatt, 1900 and Germanonautilus Mojsisovics, 1902 . It should be noted that the concept of the family had a different meaning at that time than it does today. Later the family Temnocheilidae was largely ignored and Temnocheilus was usually placed in the family Tainoceratidae . Turner (1954) then redefined the family, pointing out the close relationship between Temnocheilus and the newly described genus Subvestinautilus .</p><p>Kummel (1964) did not accept the validity of the family and considered it a synonym of the Koninckioceratidae Hyatt, 1900 . This family contained a rather heterogeneous list of genera; Temnocheilus stood next to Millkoninckioceras Kummel, 1963, Endolobus Meek &amp; Worthen, 1865, Planetoceras Hyatt, 1893, Foordiceras Hyatt, 1893 and Tylodiscoceras Miller &amp; Collinson, 1950 . In contrast, Shimansky (1967, 1979) distinguished the families Temnocheilidae and Koninckioceratidae; he even considered both groups to be independent superfamilies, each containing only one family. Dzik (1984) placed Temnocheilus and related genera in the family Trigonoceratidae and Histon (1999) followed Kummel (1964) in placing Temnocheilus in the family Koninckioceratidae .</p><p>The typical early representatives of the Temnocheilidae are known from Tournaisian and Viséan strata (Fig. 10), and it is not certain that stratigraphically younger genera really belong to the same group. This is particularly true for the records of Temnocheilus -like genera from Late Carboniferous strata of North America, which have usually been placed in the genera Temnocheilus and Latitemnocheilus . This is also true for T. annulonodosus Sturgeon, Windle, Mapes &amp; Hoare, 1982, in which Sturgeon et al. (1982) found the internal lobe to be broadly rounded and shallow with a small annular lobe. However, in Viséan representatives of Temnocheilus the internal lobe is broadly V-shaped (Korn &amp; Klug 2023).</p><p>It seems worth discussing whether the supposed Late Carboniferous temnocheilids are in fact derived from Early Carboniferous species, or whether they have arisen independently, e.g., by regression of a previously present umbilical margin. Since this cannot be resolved here, these species are provisionally and cautiously placed in the family Temnocheilidae .</p><p>Both Turner (1954) and Dzik (1984) suggested that Temnocheilus was derived from Vestinautilus . The main argument for this was the similar conch geometry; the longitudinal ridges were said to have been transformed into a ventrolateral row of nodes. For this reason, the genera Vestinautilus and Subvestinautilus are considered here to be the ancestors of the family Temnocheilidae . The material now available allows the reconstruction of a very plausible evolutionary lineage, leading from species of the Trigonoceratidae with conchs completely ornamented with longitudinal lines or ridges (e.g., Rineceras) with an increasing reduction of the number of these spiral elements to almost unornamented conchs (e.g., Knightoceras).</p><p>The position of the genus Endolobus has not yet been fully resolved. While Kummel (1964) placed it in the family Koninckioceratidae, Shimansky (1967, 1979) placed it in the family Temnocheilidae . Dzik (1984) saw Endolobus as derived from Vestinautilus in a parallel evolutionary lineage to Temnocheilus . Indeed, the rather narrow and deep internal lobe in Endolobus can be seen as a good indicator for a placement within the Temnocheilidae .</p></div>	https://treatment.plazi.org/id/03BF2F39FF8E6522701EBE698F58FC6D	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FF8F65257007BB43882FFD68.text	03BF2F39FF8F65257007BB43882FFD68.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Koninckioceratoidea Hyatt 1900	<div><p>Superfamily Koninckioceratoidea Hyatt, 1900</p><p>Diagnosis</p><p>Superfamily of the suborder Temnocheilina, in which the whorl profile shows only minor changes during ontogeny. Conch usually discoidal, subinvolute to evolute. Whorl profile elliptical or almost circular throughout ontogeny. Adult whorl profile depressed oval. Without coarse sculpture. Suture line with shallow lobes and saddles; internal lobe absent or very shallow.</p><p>Included family</p><p>Koninckioceratidae Hyatt, 1900 (Early Carboniferous to Early Permian; 2 genera, 17 species).</p><p>Remarks</p><p>Depending on the researcher, the koninckioceratids are a group that has been variously assigned to different phylogenetic lineages. Shimansky (1957, 1962) accepted them as a family within the superfamily Lirocerataceae with the genera Koninckioceras Hyatt, 1884, Lophoceras Hyatt, 1893 and Planetoceras Hyatt, 1893 . Later Shimansky (1967, 1979) elevated them to a superfamily within the suborder Rutoceratina, composed of a single family containing the three genera mentioned above.</p><p>Kummel (1963, 1964) accepted the koninckioceratids as a family within the Tainocerataceae and included eleven genera ( Millkoninckioceras Kummel, 1963, Endolobus Meek &amp; Worthen, 1865, Foordiceras Hyatt, 1893, Knightoceras Miller &amp; Owen, 1934, Subvestinautilus Turner, 1954, Temnocheilus M‘Coy, 1844 and Tylodiscoceras Miller &amp; Collinson, 1950); in other words, he combined the koninckioceratids and some of the temnocheilids into one taxon.</p><p>The superfamily Koninckoceratoidea is still poorly understood. There are several reasons for this, based on the general rarity and limited morphological inventory. Probably only one specimen of the type species of Millkoninckioceras is known, and other species, such as the Early Permian M. bibbi (Miller &amp; Kemp, 1947), can only be placed in the genus with reservations. Typically, Carboniferous and Permian nautiloids with a wide umbilicus and a depressed oval whorl profile have been assigned to Millkoninckioceras or morphologically similar genera.</p><p>The simple morphology (Fig. 14) of the species within the group makes a phylogenetic reconstruction difficult. One hypothesis for their origin is that they descended from fully coiled species in the superfamily Trigonoceratoidea with initially slightly depressed juvenile conchs. However, in contrast to the other evolutionary lineages, there was no ontogenetic change in conch geometry with the formation of a ventrolateral shoulder or an umbilical margin in the koninckioceratids. Instead, members of the Koninckioceratoidea retained the simple juvenile morphology even in the intermediate and adult growth stages.</p><p>The species of the superfamily Koninckioceratoidea are distinguished from other Late Palaeozoic nautiloids by their very simple conch morphology, with a wide umbilicus and an unsculptured shell. In contrast to almost all other coiled nautiloids, the conch shows almost no ontogenetic changes.</p></div>	https://treatment.plazi.org/id/03BF2F39FF8F65257007BB43882FFD68	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FF886524702CBC41892AFD6C.text	03BF2F39FF886524702CBC41892AFD6C.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Koninckioceratidae Hyatt 1900	<div><p>Family Koninckioceratidae Hyatt, 1900</p><p>Fig. 14</p><p>Diagnosis</p><p>Family of the superfamily Koninckioceratoidea with discoidal, subevolute to evolute conch. Whorl profile depressed oval without ventrolateral shoulder or umbilical margin. Dorsal whorl zone always very small. Shell surface usually not sculptured. Suture line is almost straight or with small lobes and saddles on the outer side of the whorl, with a rounded or funnel-shaped internal lobe. Siphuncle subcentral.</p><p>Included genera</p><p>Lophoceras Hyatt, 1893 (Viséan to Serpukhovian; 8 species).</p><p>Koninckioceras Hyatt, 1884 [nomen dubium].</p><p>Koninckoceras Hyatt, 1900 [nomen nullum].</p><p>Millkoninckioceras Kummel, 1963 (Viséan to Kasimovian; 9 species).</p><p>Remarks</p><p>Nomenclatural problems within the Koninckioceratidae were discussed in detail by Kummel (1963). The simple morphology of the conch in the Koninckioceratidae is an obstacle to analysing the origin of the group. Based on the conch morphology, an origin from genera such as Thrincoceras seems possible. An alternative would be an origin from a gyroconic or an advolute ancestor.</p></div>	https://treatment.plazi.org/id/03BF2F39FF886524702CBC41892AFD6C	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FF8965267029BC4389EFFECC.text	03BF2F39FF8965267029BC4389EFFECC.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Domatoceratina Korn 2025	<div><p>Suborder Domatoceratina subordo nov.</p><p>Diagnosis</p><p>Suborder of the order Nautilida, in which a ventrolateral shoulder and an umbilical margin are formed early in ontogeny. Conch usually discoidal, subinvolute to evolute. Juvenile whorl profile circular. Adult whorl profile subquadrate or inverted trapezoidal with a distinct ventrolateral shoulder and a distinct umbilical margin in the early species, showing modifications during evolution including a concave venter in some derived species. Dorsal whorl zone always present, but usually very small except for some derived species. Juvenile sculpture sometimes with radial ribs on the flank; adult sculpture is usually lacking except for elongate ventrolateral tubercles in derived species. Septa simply domed in most of the species, with septal inflexion in and corrugated septa in some lineages. Suture line usually depending on the whorl profile, usually with shallow lobes and low saddles, and with distinct lobes in one clade. Siphuncle in central or subcentral position.</p><p>Included superfamilies</p><p>Grypoceratoidea Hyatt, 1900 (Early Carboniferous to Late Triassic; 22 Palaeozoic genera, 91 Palaeozoic species).</p><p>Permoceratoidea Miller &amp; Collinson, 1953 (Early Permian; 2 genera, 2 species).</p><p>Subclymenioidea Shimansky, 1962 (Early to Late Carboniferous; 16 genera, 108 species).</p><p>Remarks</p><p>Taxonomy</p><p>Flower &amp; Kummel (1950) placed the Domatoceratidae in the order Centroceratida; the family was interpreted to have descended directly from the family Centroceratidae, and the domatoceratids in turn gave rise to the family Syringonautilidae . Shimansky (1957) had a similar view. He placed the family Domatoceratidae together with the families Centroceratidae, Grypoceratidae, Thrincoceratidae, Syringonautilidae and Permoceratidae in the superfamily Centrocerataceae . The origin of the suborder Domatoceratina subordo nov. was there interpreted to be in the family Centroceratidae . In contrast, Kummel (1964) placed the family Grypoceratidae, in which he included the domatoceratids, in the superfamily Trigonocerataceae . The families Syringonautilidae and Permoceratidae should have been evolved from the Grypoceratidae .</p><p>Dzik (1984) presented a very different concept for the family Grypoceratidae; he considered many previously accepted genera to be synonyms and included the genera Epidomatoceras, Stroboceras, Subclymenia and Permoceras in the family Grypoceratidae . On the other hand, he placed the genus Stenopoceras Hyatt, 1893, previously placed in Domatoceratidae, in the family Phacoceratidae .</p><p>Here, the suborder Domatoceratina subordo nov. is separated to include a group of nautilids that appears to be a monophylum, which has an origin in Early Carboniferous trigonoceratids (Dzik 1984), and, therefore, a combination with the Middle Devonian centroceratids is rejected. The suborder is characterised by a rather distinct set of characters. Most importantly, a ventrolateral shoulder and an umbilical margin are formed early in ontogeny (Fig. 3B–C, G–H). This character, together with flattened flanks and a flattened or concave venter, is maintained throughout the evolutionary history of the suborder. Only occasionally, these characters were regressed in side branches.</p><p>Morphology and subdivision</p><p>The species of Domatoceratina subordo nov. are usually easily recognisable as belonging to the suborder on the basis of their conch morphology and ornamentation. Apart from a few early representatives and some species in advanced side branches, all species are characterised by flattened flanks and an applanate or a more or weakly concave venter. The ventrolateral shoulder is usually subangular or angular and, in some species, skid-like reinforced. Another characteristic of Domatoceratina is the almost complete absence of coarse sculpture.</p><p>The following superfamilies are distinguished here:</p><p>Subclymenioidea . – Forms with usually quadrate whorl profile with a flattened or concave venter; sculpture absent or with inconspicuous ribs on the flank. Septa sometimes with a ventral inflexion causing a distinct external lobe.</p><p>Grypoceratoidea . – Forms with usually quadrate or inverted trapezoidal whorl profile with a more or less strongly flattened or concave venter; sculpture absent or with inconspicuous ribs on the flank.</p><p>Permoceratoidea . – Forms with inverted trapezoidal whorl profile with a more or less strongly flattened venter; sculpture absent or with inconspicuous ribs on the flank. Septa corrugated, causing distinct lobes and saddles.</p><p>Origin Dzik (1984: 168) proposed an origin of the grypoceratids from the Early Carboniferous Epidomatoceras . He saw Domatoceras, the stratigraphically oldest genus of the superfamily, as a direct descendant of Epidomatoceras from the Viséan.</p><p>Epidomatoceras and the family Subclymeniidae are probably derived from the Thrincoceratidae via the morphologically basal genus Maccoyoceras . The formation of the umbilical margin and ventrolateral shoulder could be considered as a new feature for the evolutionary lineage to the domatoceratids.</p><p>Phylogeny</p><p>Dzik (1984: 168) published a detailed diagram of the proposed phylogenetic relationships within the domatoceratids in the broader sense. Two major lineages can be seen in this diagram. The main lineage extends from Epidomatoceras via Domatoceras to the Triassic families Grypoceratidae and Syringonautilidae; a secondary lineage branches off from the first and extends via the Late Carboniferous Titanoceras Hyatt, 1884 and the Late Permian Pseudotitanoceras Shimansky, 1965 to the Triassic genus Germanonautilus Mojsisovics, 1902 .</p><p>Descendants</p><p>Shimansky (1957) derived the modern nautiloids (order Nautilina) from the family Domatoceratidae Miller &amp; Youngquist, 1949 . Kummel (1964) had a similar view and derived his superfamily Nautilaceae de Blainville, 1825 from the family Domatoceratidae via the family Syringonautilidae Mojsisovics, 1902 . Dzik (1984: 175) postulated a continuous evolutionary transition from the Triassic genus Syringonautilus Mojsisovics, 1902 to the Jurassic genus Cenoceras Hyatt, 1884 . According to the current state of knowledge, two further suborders can be derived from the Domatoceratina subordo nov.</p></div>	https://treatment.plazi.org/id/03BF2F39FF8965267029BC4389EFFECC	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FF8B652673FFBEE58CF1F9CE.text	03BF2F39FF8B652673FFBEE58CF1F9CE.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Subclymenioidea Shimansky 1962	<div><p>Superfamily Subclymenioidea Shimansky, 1962</p><p>Diagnosis</p><p>Superfamily of the suborder Domatoceratina subordo nov. with discoidal, subinvolute to evolute conch. Whorl profile often subquadrate to polygonal, usually with distinct ventrolateral shoulder and distinct umbilical margin. Derived species show a variation of modifications including a concave or acute venter or an angular or skid-like ventrolateral shoulder. Whorl overlap extremely small to moderate. Sculpture in most species lacking. Septa simply domed but with ventral inflexion in derived species. Suture line usually depending on the whorl profile, with shallow to deep external lobe.</p><p>Included families</p><p>Apheleceratidae Hyatt, 1893 [nomen nullum].</p><p>Subclymeniidae Shimansky, 1962 (Early to Late Carboniferous; 6 genera, 59 species).</p><p>Phacoceratidae Shimansky, 1962 (Early to Late Carboniferous; 6 genera, 13 species).</p><p>Aphelaeceratidae Shimansky, 1962 [synonym of Subclymeniidae].</p><p>Epistroboceratidae fam. nov. (Early to Late Carboniferous; 4 genera, 36 species).</p><p>Remarks</p><p>The superfamily Subclymenioidea shows a wide range of conch morphologies and sculptures and is therefore difficult to define on the basis of adult morphology. The reason for this is a rapid morphological evolution during the Late Tournaisian and Early Viséan, which produced a high diversity of conch shapes and sculptures known from only a few other clades of nautilids. The common feature of all species is the shape of the whorl profile in the juvenile stage, characterised by sharp longitudinal ridges on a raised umbilical margin.</p><p>Three evolutionary lineages can be assumed to form the superfamily Subclymenioidea:</p><p>Epistroboceratidae fam. nov. – Forms that retained the polygonal shaped whorl profile once acquired; the whorl profile became more and more compressed during evolution. Whorl profile variable, usually polygonal, sculpture with few very coarse longitudinal ridges of different strength (Fig. 15).</p><p>Subclymeniidae Shimansky, 1962 . – Forms that developed a flattened or more or less deeply concave venter. Suture line with rather deep external lobe that was caused by a septal inflexion (Fig. 16).</p><p>Phacoceratidae Shimansky, 1962 . – Forms that developed an extremely compressed whorl profile with a sharp venter (Fig. 17).</p></div>	https://treatment.plazi.org/id/03BF2F39FF8B652673FFBEE58CF1F9CE	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FF8B6518703FB9E38851FE23.text	03BF2F39FF8B6518703FB9E38851FE23.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Epistroboceratidae Korn 2025	<div><p>Family Epistroboceratidae fam. nov.</p><p>urn:lsid:zoobank.org:act: 88B59168-C65F-4FA4-832A-4E10A6FD9BF9</p><p>Fig. 15</p><p>Type genus</p><p>Epistroboceras Turner, 1954 .</p><p>Diagnosis</p><p>Family of the superfamily Subclymenioidea with usually subevolute conch. Whorl overlap very small. Whorl profile ranging from moderately depressed to moderately compressed, usually with polygonal shape. Venter usually flat. Sculpture with coarse longitudinal ridges and grooves. Suture line with broadly rounded lobes and saddles, strongly dependent on the shape of the whorl profile.</p><p>Etymology</p><p>The subfamily name refers to the type genus.</p><p>Included genera</p><p>Stroboceras Hyatt, 1884 (Tournaisian to Bashkirian; 15 species).</p><p>Epistroboceras Turner, 1954 (Tournaisian to Serpukhovian; 18 species).</p><p>Imonautilus Niko &amp; Mapes, 2007 (Serpukhovian; 1 species).</p><p>Trilobitoceras Korn &amp; Bockwinkel, 2022 (Tournaisian; 2 species).</p><p>Remarks</p><p>The genera Stroboceras and Epistroboceras have been placed in different families or subfamilies by various authors. Miller &amp; Garner (1953) placed Stroboceras in the family Rineceratidae; they derived Stroboceras from Discitoceras: “ Discitoceras most probably also gave rise to Stroboceras by certain of its longitudinal ridges becoming very large at the expense of others. Stroboceras … ” (Miller &amp; Garner 1953: 116). Turner (1954) revised Stroboceras and proposed the new genus Epistroboceras; he placed both in the family Triboloceratidae .</p><p>Shimansky (1962) placed Stroboceras and Epistroboceras in the subfamily Thrincoceratidae and later changed his mind (Shimansky 1967: 134) to assign both genera in the Trigonoceratinae . Earlier, Kummel (1964) had already included both genera in the Trigonoceratidae, without distinguishing between subfamilies. Turner (1965) included Stroboceras and Epistroboceras in the Thrincoceratinae .</p><p>Dzik (1984: 173–174) had a different concept and considered the genera Stroboceras and Epistroboceras to be not closely related and placing Stroboceras in the Grypoceratidae and Epistroboceras (as a junior synonym of Aphelaeceras Hyatt, 1884) in the Phacoceratidae . Histon (1999) followed Kummel (1964) and considered Epistroboceras to be a representative of the Trigonoceratidae .</p><p>Here, the stroboceratids are distinguished as a separate family, characterised by the presence of prominent longitudinal ridges, which in many species cause a polygonal outline to the whorl profile (Fig. 15). These ridges can be seen as a transfer of the early juvenile sculpture to the adult conch. During phylogeny, these ridges have been secondarily reduced, and in the families Subclymeniidae and Phacoceratidae they are present only in the juvenile stage. Therefore, these are also included in the superfamily Grypoceratoidea .</p></div>	https://treatment.plazi.org/id/03BF2F39FF8B6518703FB9E38851FE23	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFB5651B7025BE848CB5F9E3.text	03BF2F39FFB5651B7025BE848CB5F9E3.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Subclymeniidae Shimansky 1962	<div><p>Family Subclymeniidae Shimansky, 1962</p><p>Fig. 16</p><p>Diagnosis</p><p>Family of the superfamily Subclymenioidea with a discoidal, subinvolute to evolute conch; whorl overlap usually very small, coiling rate ranging from moderately high to extremely high. Whorl profile often with a distinct ventrolateral shoulder, a weakly convex, flat or concave venter and a rounded or subangular umbilical margin. Ornament in the early species with spiral lines in the juvenile and preadult stage; advanced species show the reduction of spiral lines. Siphuncle close to the venter. Suture line with a shallow to deep, broadly rounded or V-shaped external lobe that is produced by a ventral inflexion of the septum.</p><p>Included genera</p><p>Subclymenia d’Orbigny, 1849 (Viséan to Serpukhovian; 7 species).</p><p>Aphelaeceras Hyatt, 1884 (Tournaisian to Serpukhovian; 10 species).</p><p>Mesochasmoceras Foord, 1900 (Tournaisian; 1 species).</p><p>Maccoyoceras Miller, Dunbar &amp; Condra, 1933 (Tournaisian to Viséan; 11 species).</p><p>Epidomatoceras Turner, 1954 (Tournaisian to Serpukhovian; 17 species).</p><p>Catastroboceras Turner, 1965 (Viséan to Bashkirian; 13 species).</p><p>Pseudocatastroboceras Turner, 1965 [synonym of Catastroboceras].</p><p>Remarks</p><p>Subclymenia is a remarkable genus because it has a deeply V-shaped external lobe in the suture line (Fig. 16). Unlike many nautiloids, this lobe is not caused by the geometry of the whorl profile alone, but by a ventral inflexion of the septum. Shimansky (1962) based the family Subclymeniidae on this single genus. Kummel (1964) saw Subclymenia as a genus belonging to the family Trigonoceratidae and did not accept the family Subclymeniidae .</p><p>Turner (1965) downgraded the Subclymeniidae to a subfamily and expanded it to include the genera Maccoyoceras, Epidomatoceras, Catastroboceras and Pseudocatastroboceras . He showed that several species of the latter three of these genera also have a slightly angular external lobe. Shimansky (1967: 156) then withdrew the family Subclymeniidae and placed Subclymenia in the subfamily Aphelaeceratinae, together with the genera Aphelaeceras, Mesochasmoceras, Catastroboceras, Epidomatoceras and Maccoyoceras . Dzik (1984: 174) did not accept the systematic independence of a family Subclymeniidae and interpreted Subclymenia as a basal representative of the family Grypoceratidae .</p><p>In the Osnovy, Shimansky (1962) named the subfamily Aphelaeceratinae for the genera Aphelaeceras and Mesochasmoceras in addition to the family Subclymeniidae . According to the original description by Meek &amp; Worthen (1873: 522), the type species of Aphelaeceras has a V-shaped external lobe, indicating that it belongs to the Subclymeniidae . However, it is not clear whether the internal lobe in Aphelaeceras is caused by the shape of the whorl profile with a deeply concave venter or by a septal inflexion.</p><p>Both Turner (1965) and Shimansky (1967) included Maccoyoceras in the subfamily Subclymeniinae . However, typical specimens of Maccoyoceras have a broadly rounded external lobe and an almost central siphuncle (Histon 1999); the genus is therefore included here in the Subclymeniidae with reservations.</p><p>The Subclymeniidae are treated here as a family because the ventral inflexion of the septum is a very unusual feature. In addition, the position of the siphuncle rather close to the venter is a distinguishing feature from other families in the superfamily Subclymenioidea . The name Subclymeniidae is preferred to Aphelaeceratidae because Subclymenia characterises the family much better than Aphelaeceras .</p><p>In addition to the shape of the septum and the presence of a ventral lobe, a second important feature of the subfamily is the presence of a usually subangular ventrolateral shoulder separating the usually flattened flanks from an equally flattened or concave venter. A third feature is the more or less distinct umbilical margin, which is not present in this form in the other subfamilies of the Trigonoceratidae .</p><p>The family Subclymeniidae is not included here in the superfamily Trigonoceratoidea, because its morphological characteristics with a subangular umbilical margin suggests a transitional phylogenetic position leading to the Grypoceratoidea . The close morphological relationship favours placement in the latter superfamily.</p></div>	https://treatment.plazi.org/id/03BF2F39FFB5651B7025BE848CB5F9E3	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFB6651D7021B9C78E8AFE7A.text	03BF2F39FFB6651D7021B9C78E8AFE7A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Phacoceratidae Shimansky 1962	<div><p>Family Phacoceratidae Shimansky, 1962</p><p>Fig. 17</p><p>Diagnosis</p><p>Family of the superfamily Subclymenioidea with a usually subinvolute conch; coiling rate usually extremely high; whorl overlap small to moderate. Adult whorl profile extremely compressed with flat flanks and an acute venter. Ornament with longitudinal ridges or lines in the juvenile stage, adult conch smooth or with delicate growth lines. Position of the siphuncle between the centre of the whorl profile and the venter. Suture line without or with a very small external lobe and a broadly rounded lateral lobe.</p><p>Included genera</p><p>Phacoceras Hyatt, 1884 (Viséan to Serpukhovian; 4 species).</p><p>Leuroceras Hyatt, 1893 (Viséan; 1 species).</p><p>Diorugoceras Hyatt, 1893 (Viséan to Serpukhovian; 3 species).</p><p>Phaceras Teichert &amp; Glenister, 1952 [nomen nullum].</p><p>Epiphacoceras Turner, 1966 (Viséan; 1 species).</p><p>Askeatonoceras Turner, 1966 (Viséan; 1 species).</p><p>Pseudostenopoceras Shimansky, 1967 (Serpukhovian to? Moscovian; 3 species).</p><p>Remarks</p><p>The Phacoceratidae are one of the lesser-known families of Carboniferous nautiloids. Kummel (1964) did not accept the family and included Phacoceras and similar genera together with some Devonian genera ( Centroceras Hyatt, 1884, Carlloceras Flower &amp; Caster, 1935, Homaloceras Whiteaves, 1891, Strophiceras Hyatt, 1884) in the family Centroceratidae .</p><p>Turner (1966) devoted a special article to the Phacoceratidae and, in discussing their phylogeny, pointed out that some of the genera were monospecific, with type species known from only a few specimens or even only a single specimen. He also saw a close relationship between Phacoceras and the Devonian centroceratids and postulated an evolutionary lineage from Carlloceras (possibly Late Devonian) through Diorugoceras to Phacoceras . This scenario is mainly based on the idea that the inverted trapezoidal whorl profile of Carlloceras transformed into an oxyconic profile during evolution.</p><p>Another hypothesis was proposed by Dzik (1984: 167). He derived the Phacoceratidae, to which he also included the genera Aphelaeceras and Stenopoceras, from the stroboceratids. This phylogenetic hypothesis is quite plausible, because the morphology of the inner whorl of Phacoceras shows a morphology known from Catastroboceras, with the pronounced umbilical margin decorated by longitudinal ridges, the flattened flanks and the distinct ventrolateral shoulder (Schmidt 1951: pl. 6 fig. 4). It is therefore not necessary to propose a long and hidden evolutionary lineage including survival through the Hangenberg Event, based on poor material.</p><p>Poor preservation of type material is a problem when it comes to family composition. The two genera Epiphacoceras and Askeatomoceras newly described by Turner (1966) and Diorugoceras are based on poorly preserved material and are therefore difficult to evaluate.</p></div>	https://treatment.plazi.org/id/03BF2F39FFB6651D7021B9C78E8AFE7A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFB0651D701EBD4F882BF8B9.text	03BF2F39FFB0651D701EBD4F882BF8B9.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Grypoceratoidea Hyatt 1900	<div><p>Superfamily Grypoceratoidea Hyatt, 1900</p><p>Diagnosis</p><p>Superfamily of the suborder Domatoceratina subordo nov. with a discoidal, subinvolute to evolute conch. Whorl profile usually inverted trapezoidal with a distinct ventrolateral shoulder and a distinct umbilical margin. Derived species show a variation of modifications including a concave venter, a skid-like ventrolateral shoulder and an angular umbilical margin. Whorl overlap extremely small to moderate. Sculpture in most species lacking, in some species with short lateral ribs or ventrolateral nodes. Septa simply domed; suture line strongly dependent on the whorl profile, usually with broadly rounded lobes and narrowly rounded or subangular saddles.</p><p>Included families</p><p>Grypoceratidae Hyatt, 1900 (Early to Late Triassic).</p><p>Domatoceratidae Miller &amp; Youngquist, 1949 (Early Carboniferous to Late Permian; 15 genera, 73 species).</p><p>Stenopoceratidae fam. nov. (Early to Middle Permian; 3 genera, 11 species).</p><p>New family to be described by Korn &amp; Hairapetian (in press) (Late Permian; 4 genera, 7 species).</p><p>Remarks</p><p>Grypoceras Hyatt, 1883, Domatoceras and related genera are characterised by more or less flattened flanks, which are bordered by distinct margins against the venter and the umbilical wall (Fig. 18). Usually, the ventrolateral shoulder is more strongly pronounced than the umbilical margin, being subangular, angular or even raised to form skid-like extensions. A whorl profile with both a pronounced umbilical margin and also a pronounced ventrolateral shoulder is already present in the juvenile conch, i.e., at the end of the first whorl. In this respect, Domatoceras and related genera are similar to the metacoceratids. It is worth considering whether these two groups are closely related.</p><p>Three Carboniferous and Permian families, which represent evolutionary lineages, can be assigned to the superfamily Grypoceratoidea:</p><p>Domatoceratidae Miller &amp; Youngquist, 1949 . – Forms that retained usually inverted trapezoidal whorl profile throughout their evolutionary history (Fig. 19).</p><p>Stenopoceratidae fam. nov. – Forms that developed a very narrow venter in their evolutionary history (Fig. 20).</p><p>New family to be described by Korn &amp; Hairapetian (in press). – Forms that developed a concave venter, partly separated from a skid-like ventrolateral shoulder, in their evolutionary history (Fig. 21).</p></div>	https://treatment.plazi.org/id/03BF2F39FFB0651D701EBD4F882BF8B9	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFB1651E73DABE698FF6F89C.text	03BF2F39FFB1651E73DABE698FF6F89C.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Domatoceratidae Miller & Youngquist 1949	<div><p>Family Domatoceratidae Miller &amp; Youngquist, 1949</p><p>Figs 18A–B – 19</p><p>Diagnosis</p><p>Family of the superfamily Grypoceratoidea with a thinly to thickly discoidal, subinvolute to evolute conch. Whorl profile in the adult stage usually compressed subquadrate or inverted trapezoidal. Umbilical margin distinct or sharp; ventrolateral shoulder nearly rectangular to broadly rounded, rarely skid-like. Ornament consisting of fine growth lines; some species have tubercles on the ventrolateral shoulder. Suture line always with rounded but distinct external, lateral and internal lobes separated by a narrowly rounded or subacute saddles; without annular process.</p><p>Included genera</p><p>Pselioceras Hyatt, 1884 (Wuchiapingian to Changhsingian; 3 species).</p><p>Titanoceras Hyatt, 1884 (Virgilian; 2 species).</p><p>Domatoceras Hyatt, 1891 (Moscovian to Changhsingian; 38 species).</p><p>Pseudometacoceras Miller, Dunbar &amp; Condra, 1933 [synonym of Domatoceras Hyatt, 1891]. Paradomatoceras Delépine, 1937 (Bashkirian; 1 species).</p><p>Plummeroceras Kummel, 1953 (Artinskian; 1 species).</p><p>Neodomatoceras Ruzhencev &amp; Shimansky, 1954 (Artinskian; 2 species).</p><p>Parapenascoceras Ruzhencev &amp; Shimansky, 1954 (Kasimovian to Roadian; 7 species).</p><p>Penascoceras Ruzhencev &amp; Shimansky, 1954 (Kungurian to Roadian; 3 species).</p><p>Permodomatoceras Ruzhencev &amp; Shimansky, 1954 (Artinskian to Wuchiapingian; 6 species). Stenodomatoceras Ruzhencev &amp; Shimansky, 1954 (Kasimovian; 4 species).</p><p>Virgaloceras Schindewolf, 1954 (Changhsingian; 1 species).</p><p>Neostenopoceras Zhao, Liang &amp; Zheng, 1978 (Changhsingian; 1 species).</p><p>Shatoceras Leonova &amp; Shchedukhin, 2020 (Asselian; 1 species).</p><p>Omorphoceras Leonova &amp; Shchedukhin, 2023 (Asselian or Sakmarian; 1 species).</p><p>New genus A to be described by Korn &amp; Ghaderi (in press) (Wuchiapingian to Changhsingian; 2 species).</p><p>Remarks</p><p>As with other families of Carboniferous and Permian nautilids, the justification and content of the family Domatoceratidae has been the subject of much debate; the views of the various authors were differing widely. When first described, Miller &amp; Youngquist (1949) placed the five genera Domatoceras, Pselioceras, Stearoceras Hyatt, 1893, Stenopoceras and Titanoceras in the family Domatoceratidae . Kummel (1953) did not accept the family and synonymised it with the family Grypoceratidae . Moreover, he even considered Domatoceras to be a subgenus of Grypoceras . The genera and subgenera included by him in the Grypoceratidae were Grypoceras (Grypoceras), Grypoceras (Domatoceras), Grypoceras (Plummeroceras), Gryponautilus Mojsisovics, 1902, Stenopoceras, Menuthionautilus Collignon, 1933, Stearoceras, Titanoceras and Pselioceras .</p><p>Ruzhencev &amp; Shimansky (1954) discussed the taxa belonging to this group in detail and included the four already known genera Domatoceras, Titanoceras, Pselioceras and Stenopoceras as well as the six newly named genera Penascoceras, Parapenascoceras, Permodomatoceras, Neodomatoceras, Stenodomatoceras and Parastenopoceras Ruzhencev &amp; Shimansky, 1954 . In the Osnovy (Shimansky 1962), the group was listed only as a subfamily within the family Grypoceratidae . In addition to the ten genera already mentioned, Paradomatoceras, Plummeroceras (as a subgenus of Domatoceras), Virgaloceras and Menuthionautilus were also included, the latter being the only Triassic genus.</p><p>In the Treatise, Kummel (1964) reiterated his previously published view and did not accept the Domatoceratidae as a valid family. He considered the genera Stenodomatoceras, Penascoceras and Permodomatoceras newly named by Ruzhencev &amp; Shimansky (1954) to be synonyms of Domatoceras and Parapenascoceras and Neodomatoceras as synonyms of Stearoceras . He included the genus Epidomatoceras in the family Grypoceratidae .</p><p>Sobolev (1989) did not accept the independence of a family Domatoceratidae either and included the corresponding genera in the family Grypoceratidae . However, he accepted the validity of the Permian genera named by Ruzhencev &amp; Shimansky (1954) but did not include Epidomatoceras in the family.</p><p>As in other Carboniferous–Permian nautilid families, the possible phylogenetic and systematic relationships in the Domatoceratidae (or Grypoceratidae) have been intensively discussed. Ruzhencev &amp; Shimansky (1954) followed the concept that the systematics should be based on phylogeny; they therefore divided the family into a number of genera according to hypothetical evolutionary lineages. This contrasted sharply with other approaches, such as that of Kummel (1953: 45), who had stated: “As an evolutionary unit this family appears to be closely integrated. The extensive variations experimented with in this family keep an over-all unity in both the shape of the conch and sutural development.” As a consequence, Kummel (1964) distinguished considerably fewer independent genera than Ruzhencev &amp; Shimansky (1954) and Shimansky (1962).</p><p>A reconstruction of the phylogeny was undertaken by Dzik (1984). He derived the species of the family Domatoceratidae (which he included in the Grypoceratidae) from the Early Carboniferous genus Epidomatoceras and subdivided it into several long-ranging evolutionary lineages extending from the Carboniferous to the Triassic. Contrary to earlier concepts (Shimansky 1957; Kummel 1964), he placed Germanonautilus in the evolutionary lineage of Titanoceras and the Syringonautilidae Mojsisovics, 1902 in the lineage of Domatoceras . According to this reconstruction, Stenopoceras is separated from the Grypoceratidae and is considered a descendant of Phacoceras in the family Phacoceratidae .</p><p>An unanswered question is still whether certain morphological variations within the family Domatoceratidae occurred only once or iteratively. These characters include (1) the formation of a concave venter, (2) the formation of an angular ventrolateral margin and ventrolateral skids, (3) the formation of an angular umbilical margin, (4) the narrowing (but also widening) of the umbilicus, (5) the change to more compressed or depressed whorl profiles and (6) the development of ventrolateral tubercles. For example, it is not clear whether the separation of the genera Stenodomatoceras and Permodomatoceras from Domatoceras, which was justified by the reduction in umbilical width and whorl height, respectively, actually occurred only once. Therefore, it is not possible to say with certainty whether these genera are monophyletic units.</p></div>	https://treatment.plazi.org/id/03BF2F39FFB1651E73DABE698FF6F89C	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFBC65107043BE698F2FFD33.text	03BF2F39FFBC65107043BE698F2FFD33.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Stenopoceratidae Korn 2025	<div><p>Family Stenopoceratidae fam. nov.</p><p>urn:lsid:zoobank.org:act: B054DF35-5864-4B11-A32D-33C1E7ACC7BE</p><p>Figs 18C, 20</p><p>Type genus</p><p>Stenopoceras Hyatt, 1893 .</p><p>Diagnosis</p><p>Family of the superfamily Grypoceratoidea with an extremely discoidal to thinly discoidal, involute conch. Whorl profile in the adult stage compressed with very narrow venter. Ornament consisting of fine growth lines. Suture line always with rounded and small external lobe and broadly rounded lateral lobe separated by a subacute saddle, without annular process.</p><p>Etymology</p><p>The family name refers to the type genus.</p><p>Included genera</p><p>Stenopoceras Hyatt, 1893 (Bashkirian to Roadian; 9 species).</p><p>Parastenopoceras Ruzhencev &amp; Shimansky, 1954 (Artinskian; 1 species).</p><p>Leptodomatoceras Leonova &amp; Shchedukhin, 2023 (Asselian or Sakmarian; 1 species).</p><p>Remarks</p><p>The genera of the family Stenopoceratidae were previously placed in the family Domatoceratidae (Miller &amp; Youngquist 1949; Ruzhencev &amp; Shimansky 1954), in the family Grypoceratidae (Kummel 1953, 1964; Shimansky 1967, 1979), in the subfamily Domatoceratinae (Shimansky 1962) or in the family Phacoceratidae (Dzik 1984) . However, Ruzhencev &amp; Shimansky (1954: 51) proposed an evolutionary lineage with Stenopoceras as the terminal genus. This separate lineage is used here to name a separate family characterised by increasing compression of the whorl profile, closure of the umbilicus and narrowing of the venter.</p></div>	https://treatment.plazi.org/id/03BF2F39FFBC65107043BE698F2FFD33	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFBE651273CFBBD58F55FA84.text	03BF2F39FFBE651273CFBBD58F55FA84.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Permoceratoidea Miller & Collinson 1953	<div><p>Superfamily Permoceratoidea Miller &amp; Collinson, 1953</p><p>Fig. 22</p><p>[nom. transl., ex Permoceratidae Miller &amp; Collinson, 1953 .]</p><p>Diagnosis</p><p>Superfamily of the suborder Domatoceratina subordo nov. with discoidal, involute conch. Suture line with distinct, deeply V-shaped external lateral and internal lobs and two small, rounded umbilical lobes.</p><p>Included family</p><p>Permoceratidae Miller &amp; Collinson, 1953 (Early Permian; 2 genera, 2 species).</p><p>Remarks</p><p>Permonautilus, and thus the family Permoceratidae, is based on the species described by Haniel (1915) as “ Nautilus (Aganides) bitauniensis ” (Fig. 22). According to Haniel (1915) the material comes from the “Bitauni beds”, which have a late Early Permian age. Miller &amp; Collinson (1953) discussed this species and created the new genus Permoceras and the family Permoceratidae for it. They based this taxonomic classification on the peculiarity of the suture line; in contrast to all other Permian nautilids, P. bitauniense has a complex suture with eight lobes. They compared the species with Pseudonautilus geinitzi (Oppel, 1865) from Late Jurassic strata in Moravia, a species that is almost identical in both conch geometry and suture line. Nevertheless, Miller &amp; Collinson (1953) decided to create a new genus and family. The reason they gave was the considerable stratigraphic distance between Permonautilus and Pseudonautilus .</p><p>The family Permoceratidae was placed in the superfamily Centrocerataceae by Shimansky (1957, 1962, 1967, 1979) and in the superfamily Trigonocerataceae by Kummel (1964). Dzik (1984) did not recognise the independence of the family and placed Permoceras in the family Grypoceratidae . However, the very peculiar suture line, which differs greatly from all other Palaeozoic nautilids, justifies a separation at a high taxonomic level, and the family is therefore elevated to the rank of a superfamily.</p><p>The phylogenetic origin of Permoceras has long been considered unclear. Dzik (1984: 168, text-fig. 65) linked Permoceras as a short evolutionary lineage to Neodomatoceras, a genus with comparatively similar conch proportions but a very simple domatoceratid suture. Leonova &amp; Shchedukhin (2023) presented Foveroceras Leonova &amp; Shchedukhin, 2023 as a probable transitional form linking Permoceras with members of the Domatoceratidae . Foveroceras has a discoidal involute conch with a flat venter and is characterised by a deep and narrow outer lobe, a deep blunt lateral lobe, a fairly deep umbilical lobe and a very narrow deep internal lobe.</p></div>	https://treatment.plazi.org/id/03BF2F39FFBE651273CFBBD58F55FA84	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFBF651273F5BA2A894AF917.text	03BF2F39FFBF651273F5BA2A894AF917.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Permoceratidae Miller & Collinson 1953	<div><p>Family Permoceratidae Miller &amp; Collinson, 1953</p><p>Fig. 22</p><p>Diagnosis</p><p>Family of the superfamily Permoceratoidea with a discoidal, involute conch. Suture line with distinct, deeply V-shaped external lateral and internal lobs and two small, rounded umbilical lobes.</p><p>Included genera</p><p>Permoceras Miller &amp; Collinson, 1953 (Kungurian; 1 species).</p><p>Foveroceras Leonova &amp; Shchedukhin, 2023 (Asselian or Sakmarian; 1 species).</p></div>	https://treatment.plazi.org/id/03BF2F39FFBF651273F5BA2A894AF917	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFBF65177024B9B88856F85F.text	03BF2F39FFBF65177024B9B88856F85F.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Tainoceratina Shimansky 1957	<div><p>Suborder Tainoceratina Shimansky, 1957</p><p>Fig. 23</p><p>Diagnosis</p><p>Suborder of the order Nautilida, in which a ventrolateral shoulder and an umbilical margin are formed early in ontogeny in the advanced species. Conch usually discoidal, subinvolute to evolute. Juvenile whorl profile depressed oval or circular. Adult whorl profile depressed oval or reniform in the early species, showing numerous modifications during evolution (inverted trapezoidal, trapezoidal or polygonal whorl profiles or with ventral depression). Dorsal whorl zone always present, but usually very small. Juvenile sculpture with radial ribs on the flank; adult sculpture with radial ribs on the flank, ventrolateral nodes or several rows of nodes in derived species. Septa simply domed, with dorsal inflexion in advanced species. Suture line depending on the whorl profile, with shallow lobes and low saddles. Siphuncle in central or subcentral position.</p><p>Included superfamilies</p><p>Tainoceratoidea Hyatt, 1883 (Late Carboniferous to Early Triassic; 23 Palaeozoic genera, 89 Palaeozoic species).</p><p>Pleuronautiloidea Hyatt, 1900 (Late Carboniferous to Late Triassic; 32 Palaeozoic genera, 190 Palaeozoic species).</p><p>Remarks</p><p>Taxonomy</p><p>A number of different concepts have been published with regard to the taxonomic composition and subdivision of the Tainoceratina . In the concept used here and in contrast to earlier authors, the suborder Tainoceratina is more restricted in size and several taxa of different rank are excluded, such as the Rutoceratidae, the Temnocheilidae and the Koninckioceratidae . Accordingly, the stratigraphic range of the suborder Tainoceratina is considered here from Viséan to Triassic.</p><p>Morphology and subdivision</p><p>The phylogenetic scheme proposed by Shimansky (1957, 1962) distinguished four evolutionary lineages, translated in superfamilies within the suborder Tainoceratina: Tainocerataceae Hyatt, 1883, Encoilocerataceae Shimansky &amp; Erlanger, 1955, Temnocheilaceae Mojsisovics, 1902 and Rhiphaeocerataceae Ruzhencev &amp; Shimansky, 1954 . According to this scheme, the clade consisting of the superfamilies Tainocerataceae and Encoilocerataceae and the clade consisting of the families Gzheloceratidae Ruzhencev &amp; Shimansky, 1954, Rhiphaeoceratidae Ruzhencev &amp; Shimansky, 1954 and Aktubonautilidae Ruzhencev &amp; Shimansky, 1954 are monophyletic, respectively.</p><p>Kummel (1964) included the families Rutoceratidae, Tetragonoceratidae, Tainoceratidae, Rhiphaeoceratidae and Koninckioceratidae in the Tainocerataceae and postulated a Devonian to Triassic range for the superfamily. For the three superfamilies Aipocerataceae, Trigonocerataceae and Clydonautilaceae, he did not provide a clear phylogenetic hypothesis of origin, but suggested that they, like the tainoceratids, were derived from the Rutoceratidae or another ancestral family in the Devonian.</p><p>Dzik (1984) used the suborder Tainoceratina for practical reasons to include almost all Late Palaeozoic and Triassic nautiloids; he did not distinguish superfamilies, but rather separated the families Trigonoceratidae, Tainoceratidae, Grypoceratidae, Clydonautilidae, Syringonautilidae and Liroceratidae . It is worth noting that he only included post-Devonian taxa in the Tainoceratina .</p><p>Here, the suborder Tainoceratina is reduced to include only the superfamilies Tainoceratoidea and Pleuronautiloidea . This classification is based on phylogenetic considerations based on some key morphological characters. A common morphological feature of the two superfamilies is the early ontogenetic development of both a subangular ventrolateral shoulder and a subangular umbilical margin in the advanced species (Fig. 3D, I). Radial ribs appear in the juvenile conch within several lineages. The general shape of the conch is discoidal and subevolute; subinvolute and evolute conchs are an exception. Tainoceratids are very conservative in this respect; Carboniferous, Permian and Triassic species can have very similar conch morphologies, but the latter probably regularly possess a dorsal inflexion of the septum, causing an annular process.</p><p>The two superfamilies are characterised by the following main morphological features:</p><p>Tainoceratoidea . – Forms with usually octagonal whorl profile with a more or less deep mid-ventral longitudinal groove; sculpture usually with several rows of nodes (Fig. 23A).</p><p>Pleuronautiloidea . – Forms with usually quadrate, trapezoidal or inverted trapezoidal whorl profile with a more or less strongly flattened venter; sculpture usually with ventrolateral nodes and ribs on the flank, sometimes with more or less long spines (Fig. 23B).</p><p>Origin</p><p>The origin of the suborder Tainoceratina (as interpreted here) is not completely resolved. Ruzhencev &amp; Shimansky (1954) saw the origin of the tainoceratids (in a more general view) in the Devonian family Tetragonoceratidae Flower, 1945 and derived the Tainoceratina from the family Rutoceratidae Hyatt, 1884 . Shimansky (1967: 39) stated that the family Gzheloceratidae, which was considered to be the ancestral family from which the family Tainoceratidae and others were derived, arose directly from the family Rutoceratidae .</p><p>Dzik (1984: 160) proposed an alternative origin for the tainoceratids. Most importantly, he proposed parallel evolutionary lineages within the group, here separated as the superfamilies Tainoceratoidea and Pleuronautiloidea . Dzik associated Tainoceras Hyatt, 1883 with the Viséan to Serpukhovian genus Tylonautilus Pringle &amp; Jackson, 1928, which like Tainoceras has a polygonal whorl profile with a midventral groove and a sculpture with ribs and rows of nodules or tubercles. This hypothesis would imply a Bashkirian to early Gzhelian interval between the last occurrence of the ancestor Tylonautilus and the first of the descendant Tainoceras . Dzik also formulated the hypothesis that Tylonautilus was derived from the Viséan genus Celox Shimansky, 1967 .</p><p>Dzik saw the origin of the group described here as Pleuronautiloidea in Early Carboniferous representatives of the genus Gzheloceras Ruzhencev &amp; Shimansky, 1954, which are now attributed to Pseudogzheloceras Dernov, 2021 (Dernov 2021). According to this hypothesis (Dzik 1984: 160), Gzheloceras should be derived from the genus Celox, which in turn should have been derived from the Tournaisian to Viséan genus Vestinautilus . This would mean that the superfamilies Tainoceratoidea Hyatt, 1883 and Pleuronautiloidea Hyatt, 1900 have a common ancestor in the genus Celox . At the same time, it means that the angular umbilical margin was acquired independently later in the evolution of the two superfamilies.</p><p>This hypothesis for the origin of the tainoceratids in the strict sense, formulated by Dzik (1984), seems to be the most plausible in view of the available data. Within the genus Vestinautilus and closely related genera, the transition from the Tournaisian to the Viséan was marked by a progressive simplification of shell ornamentation, with the loss of the original spiral ridges and the strongly pronounced ventrolateral shoulder. Such a morphological trend including the new formation of lateral ribs could have led to genera such as Celox and Pseudogzheloceras .</p><p>As an alternative to a phylogenetic origin in the genus Vestinautilus, the tainoceratids could be derived from originally more evolute and discoidal species. Representatives of the family Subclymeniidae, in particular the genera Maccoyoceras and Epidomatoceras, are possible candidates. This would mean that the Tainoceratina and Domatoceratina subordo nov. are largely sister groups.</p><p>Phylogeny</p><p>Dzik (1984: text-fig. 62) drew a complex system of relationships with a number of parallel evolutionary lineages within the group, the most important of which are:</p><p>(1) Gzheloceras – Pleuronautilus: this evolutionary lineage already began in the Early Carboniferous with Pseudogzheloceras memorandum Shimansky, 1967 and continued through the Late Carboniferous and Permian with species of Pseudogzheloceras and Gzheloceras . In the Early Permian, this lineage included species now classified as Pseudofoordiceras Ruzhencev &amp; Shimansky, 1954 . According to this phylogenetic reconstruction, a separate lineage continued into the Triassic and was represented by Pleuronautilus trinodosus Mojsisovics, 1882 and other species of the same genus.</p><p>(2) Gzheloceras – Metacoceras dorashamense, M. dorsoarmatum – Pleuronautilus pichleri: this evolutionary lineage began in the Bashkirian with Pseudogzheloceras faticatum Shimansky, 1967 and continued into the Permian via P. tacitum Shimansky, 1967 (Moscovian) and P. maklai Shimansky, 1967 (Kasimovian). From the Wuchiapingian, the species “ Metacoceras dorashamense ”, “ M. dorsoarmatum ” and “ Pleuronautilus dzhulfensis ” belong in this lineage. Survivors into the Triassic formed the species Pleuronautilus pichleri author+year and the genera Encoiloceras Hyatt, 1900 and Anoploceras Hyatt, 1900 .</p><p>(3) Pseudotemnocheilus – Tirolonautilus: this evolutionary lineage began in the Moscovian with Temnocheiloides acanthicus (Tzwetaev, 1888) and continued in the Permian with Pseudotemnocheilus Ruzhencev &amp; Shimansky, 1954 and Tirolonautilus Mojsisovics, 1902 . Two side branches were represented by Cooperoceras Miller, 1945 and Articheilus Ruzhencev &amp; Shimansky, 1954, respectively.</p><p>(4) Metacoceras – Enoploceras, Mojsvaroceras: this evolutionary lineage began in the Kasimovian with Metacoceras mcchesneyi Murphy, 1970 and continued throughout the Permian. In the Triassic there was a diversification into different genera ( Enoploceras Hyatt, 1900, Mojsvaroceras Hyatt, 1883).</p></div>	https://treatment.plazi.org/id/03BF2F39FFBF65177024B9B88856F85F	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFBB65167010BE698856F863.text	03BF2F39FFBB65167010BE698856F863.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Pleuronautiloidea Hyatt 1900	<div><p>Superfamily Pleuronautiloidea Hyatt, 1900</p><p>Diagnosis</p><p>Superfamily of the suborder Tainoceratina with a discoidal, subinvolute to subevolute conch. Whorl profile in early species subquadrate with distinct ventrolateral shoulder and distinct umbilical margin. Derived species show a variation of modifications including trapezoidal, inverted trapezoidal or hexagonal whorl profiles with a less angular ventrolateral shoulder and umbilical margin. Whorl overlap is always very small. Sculpture in early species with transverse ribs and ventrolateral nodes, in derived species often with ribs and several rows of nodes. Septa simply domed, in derived species with a dorsal inflexion that produces an annular process. Suture line with broadly rounded lateral lobe and shallow lobe or low saddle on the venter.</p><p>Included families</p><p>Pleuronautilidae Hyatt, 1900 (Middle Permian to Late Triassic; 1 Permian genus, 10 Permian species).</p><p>Gzheloceratidae Ruzhencev &amp; Shimansky, 1954 (Early Carboniferous to Early Permian; 5 genera, 37 species).</p><p>Mosquoceratidae Ruzhencev &amp; Shimansky, 1954 (Late Carboniferous to Early Permian; 3 genera, 11 species).</p><p>Aktubonautilidae Ruzhencev &amp; Shimansky, 1954 (Early Permian; 2 genera, 2 species).</p><p>Rhiphaeoceratidae Ruzhencev &amp; Shimansky, 1954 (Early to Late Permian; 6 genera, 15 species).</p><p>Metacoceratidae fam. nov. (Late Carboniferous to Late Permian; 12 genera, 101 species).</p><p>Foordiceratidae fam. nov. (Middle to Late Permian; 3 genera, 14 species).</p><p>Remarks</p><p>Based on the phylogenetic reconstruction that was proposed by Dzik (1984), six families within the superfamily Pleuronautiloidea are distinguished here and briefly characterised as follows:</p><p>Metacoceratidae fam. nov. – Ancestral taxa with a commonly subquadrate or weakly depressed whorl profile; sculpture with conical ventrolateral nodes and sometimes with dorsolateral nodes and ribs on the flank (Fig. 24).</p><p>Gzheloceratidae Ruzhencev &amp; Shimansky, 1954 . – Ancestral taxa with a small conch and an elliptical or reniform whorl profile; sculpture with short ribs or transversely elongated tubercles in the middle of the flank (Fig. 25A).</p><p>Aktubonautilidae Ruzhencev &amp; Shimansky, 1954 . – Taxa with a semicircular or reniform whorl profile and a broadly rounded venter; sculpture with elongate nodes on the flank (Fig. 25B).</p><p>Mosquoceratidae Ruzhencev &amp; Shimansky, 1954 . – Taxa with a trapezoidal whorl profile and a convex venter; sculpture with longitudinally elongated tubercles on the outer flank (Fig. 26).</p><p>Rhiphaeoceratidae Ruzhencev &amp; Shimansky, 1954 . – Taxa with an oval, reniform or trapezoidal whorl profile and a flattened venter; sculpture with short ribs on the flank (Fig. 27).</p><p>Foordiceratidae fam. nov. – Derived taxa with a trapezoidal whorl profile and a flattened venter; sculpture with coarse ribs or coarse conical nodes on the outer flank (Fig. 28).</p><p>Pleuronautilidae Hyatt, 1900 . – Derived taxa with parallel or convergent flanks and rounded ventrolateral shoulder; sculpture with coarse ribs and sometimes with multiple rows of nodes (Fig. 29).</p><p>The absence of the midventral groove separates the Pleuronautiloidea from the Tainoceratoidea . In addition, the species of the Pleuronautiloidea usually have a rectangular, trapezoidal or inverted trapezoidal whorl profile, whereas the Tainoceratoidea have a polygonal whorl profile. The sculpture of the Pleuronautiloidea does not have the characteristic rows of nodes typical for the Tainoceratoidea .</p></div>	https://treatment.plazi.org/id/03BF2F39FFBB65167010BE698856F863	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFA4650A707FBE698FB7FC0D.text	03BF2F39FFA4650A707FBE698FB7FC0D.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Metacoceratidae Korn 2025	<div><p>Family Metacoceratidae fam. nov.</p><p>urn:lsid:zoobank.org:act: 0391FE98-A7EB-4C7A-9EDF-331C197C3EF4</p><p>Fig. 24</p><p>Type genus</p><p>Metacoceras Hyatt, 1883 .</p><p>Diagnosis</p><p>Family of the superfamily Pleuronautiloidea with an equidimensional or more commonly weakly depressed, trapezoidal to inverted trapezoidal whorl profile. Venter usually flattened, but ranging from slightly convex to slightly concave. Ventrolateral shoulder often prominent, ranging from broadly rounded to subangular. Flanks weakly convergent, parallel or weakly divergent, usually flattened and ranging from weakly convex to weakly concave. Umbilical margin usually pronounced, usually subangular in the intermediate growth stage. Sculpture with ventrolateral conical nodes, often with dorsolateral nodes and low ribs on the flank. Suture line with shallow lobes and low saddles. Internal lobe very shallow, without annular process.</p><p>Etymology</p><p>The family name refers to the type genus.</p><p>Included genera</p><p>Metacoceras Hyatt, 1883 (Moscovian to Roadian; 45 species).</p><p>? Shansinautilus Yabe &amp; Mabuti, 1935 (Roadian; 1 species).</p><p>Cooperoceras Miller, 1945 (Kungurian; 1 species).</p><p>Epimetacoceras Librovitch, 1946 (Carboniferous) (nomen nudum).</p><p>Pseudofoordiceras Ruzhencev &amp; Shimansky, 1954 (Artinskian to Kungurian; 7 species). Pseudotemnocheilus Ruzhencev &amp; Shimansky, 1954 (Artinskian to? Changhsingian; 11 species). Tanchiashanites Zhao, 1954 (Roadian; 1 species).</p><p>Mahoningoceras Murphy, 1974 (Moscovian; 3 species).</p><p>Lichuanoceras Xu, 1977 (Wuchiapingian; 1 species).</p><p>Sinotitanoceras Pan, 1983 (Kungurian; 1 species).</p><p>Anthodiscoceras Qin, 1986 (Wuchiapingian; 1 species)?</p><p>New genus C to be described by Korn &amp; Ghaderi (in press) (Wuchiapingian to Changhsingian; 22 species).</p><p>Mojsvaroceras Hyatt, 1883 (Triassic).</p><p>Huanghoceras Yin, 1933 (Asselian to Wuchiapingian; 8 species).</p><p>Remarks</p><p>Miller et al. (1933: 166) placed six Pennsylvanian genera from the American Midcontinent in the family Tainoceratidae, namely Tainoceras, Temnocheilus, Metacoceras, Endolobus, Titanoceras and Coelogasteroceras Hyatt, 1893 . This list contains a very heterogeneous collection of genera, but the authors were aware of a serious problem: “The classification of the nautiloid cephalopods is not in a satisfactory condition as is that of most of the other major groups of fossil invertebrates.” (Miller et al. 1933: 38). They discussed an earlier idea expressed by Girty (1915) to subdivide the genus Metacoceras into subgenera or genera, but concluded that “… such subdivision, however justifiable it may be from a phylogenic point of view, is so difficult, if not impossible to carry through in practice, that it would lead to endless confusion.” Consequently, they listed about 25 Carboniferous taxa at the species level.</p><p>Miller &amp; Youngquist (1949: 105) discussed the genus Metacoceras including the Permian material and repeated the problems posed by the wide range of variation in conch shape and ornament: “Normally, we would be inclined to regard many of the forms under consideration as varieties of established species, but such a procedure does not seem to be practicable in this case because of the extreme amount of variation in all of the characters involved. Therefore, more or less as a matter of expediency, we are recognizing most of the variants as distinct species.” Miller &amp; Youngquist (1949) restricted Metacoceras to those species with conical nodes only on the outer flank or the ventrolateral shoulder; species with ventrolateral nodes extending as ribs onto the flank were assigned to Foordiceras . Because of this interpretation, they stated that many of the species formerly referred to Metacoceras should be better placed in Foordiceras .</p><p>Kummel (1953: 19) proposed a different concept for the genus Metacoceras and understood it with a much wider morphological range. He separated the two subgenera M. ( Metacoceras) and M. ( Mojsvaroceras), the former with nearly 50 species occurring in the Carboniferous and Permian and the latter with 17 species in the Triassic. Kummel did not accept the placement of species with umbilical nodes in Foordiceras as done by Miller &amp; Youngquist (1949), instead he stated: “The basic pattern of ornamentation of Metacoceras is that of ventrolateral and umbilical nodes.” However, at the same time he stated: “The species can be separated into two groups, the first including those that have only ventrolateral nodes, and the second those that have both ventrolateral and umbilical nodes.”</p><p>Contrary to Miller &amp; Youngquist (1949), Kummel (1953) saw close relationships between the genera Metacoceras and Pleuronautilus and transferred a number of Permian species that were previously assigned to Metacoceras to Pleuronautilus, although they show close affinities to Metacoceras . This reduced the number of species of Metacoceras but made Pleuronautilus a very large genus, spanning the Early Permian to the Late Triassic. Kummel estimated that there may be 58 species in the subgenus Pleuronautilus (Pleuronautilus), 24 of which are from the Permian. It is worth noting that Kummel argued that many Permian tainoceratid species previously assigned to Metacoceras or Foordiceras should be placed in Pleuronautilus based on the presence of radial ribs: “Many of these species appear to be transitional between Metacoceras and the Triassic Pleuronautilus and should be placed in the latter genus.” (Kummel 1953: 34). He listed the species, including “ Nautilus dorso armatus ” from Dzhulfa, under Pleuronautilus (Pleuronautilus) .</p><p>Ruzhencev &amp; Shimansky (1954) proposed an alternative approach, which was very different from those previously outlined; their approach was based on proposed phylogenetic relationships that should be expressed in the classification of Metacoceras and its relatives. These authors had excellently preserved material for study and were therefore able to include the size, shape and ornamentation of early juvenile conch in their phylogenetic analysis. Ruzhencev &amp; Shimansky (1954: 45) postulated that there are two separate evolutionary lineages within Metacoceras; the European species (including those from the South Urals) are characterised by a single row of tubercles on the ventrolateral shoulder, whereas the American species possess one row of tubercles on the ventrolateral shoulder and another on the umbilical margin. They reduced the extend of the genus Metacoceras by separating the North American Permian species with ribs on the flank as Pseudofoordiceras . Furthermore, they accepted the Asian genera Huanghoceras and Shansinautilus .</p><p>In the Treatise of Invertebrate Paleontology, Kummel (1964) expressed a much more restrictive view on the tainoceratids. He did not accept the families Gzheloceratidae and Mosquoceratidae that were previously established by Ruzhencev &amp; Shimansky (1954) and included them in the Tainoceratidae . Furthermore, ignoring the family Mosquoceratidae, he synonymised Mosquoceras Ruzhencev &amp; Shimansky, 1954 with Metacoceras and Articheilus and placed Leonardocheilus Ruzhencev &amp; Shimansky, 1954 in synonymy with Temnocheilus . He also synonymised a number of other genera such as Huanghoceras and Shansinautilus . In summary, Kummel’s attempt suggested the existence of some long-ranging and geographically widespread genera ( Metacoceras, Pleuronautilus) with a very large number of species.</p><p>Shimansky (1965), when describing the Late Permian nautiloids from Dzhulfa, noted the transitional morphology of “ Metacoceras dorsoarmatum ” and “ M. dorashamense ” with “ Pleuronautilus dzhulfensis ”. It seems that Shimansky avoided to name a clear character to separate the two genera.</p><p>Metacoceras remained a species-rich genus. Shimansky (1967) listed 34 species, about half of which were from the Late Carboniferous and half from the Permian. He also listed 19 Permian species of Pleuronautilus, including some that had been assigned to the genera Huanghoceras and Pseudofoordiceras in an earlier paper (Ruzhencev &amp; Shimansky 1954). These two genera as well as Shansinautilus Yabe &amp; Mabuti, 1935 and Tungkuanoceras Hajasaka, 1947 were synonymised with Pleuronautilus .</p><p>Teichert &amp; Kummel (1973), when describing the nautiloids from the Iranian side of the Aras Valley, accepted the separation of Metacoceras (with “ Metacoceras dorsoarmatum ” and “ M. dorashamense ”) and Pleuronautilus (with “ Pleuronautilus sp. indet. 1”) as previously outlined in a similar way by Shimansky (1965). Like Shimansky, they did not provide a clear reason for this choice of separation.</p><p>Sturgeon et al. (1997: 31) discussed in detail the morphological spectrum of Metacoceras and its relationships with other tainoceratid genera. They included Late Carboniferous species with lateral ribs and umbilical nodes in Metacoceras .</p><p>An alternative division of families within the superfamily Pleuronautiloidea is proposed here. The family Metacoceratidae includes all genera that have a trapezoidal to inverted trapezoidal whorl profile and whose sculpture consists largely of ventrolateral nodes.</p><p>The family Metacoceratidae is distinguished from the other families of the superfamily Pleuronautiloidea by the following criteria:</p><p>The main difference with the partly rather similar species of the Pleuronautilidae is the sculpture, which in the Pleuronautilidae consists mainly of sharp ribs on the flanks, whereas in the Metacoceratidae it consists mainly of conical nodes and a few low and mostly rounded ribs.</p><p>The families Mosquoceratidae and Aktubonautilidae differ from the Metacoceratidae in the very large juvenile whorl; the families Gzheloceratidae and Rhiphaeoceratidae differ from the Metacoceratidae in the more elliptical whorl cross section and, at least partly, in the presence of coarse transverse ribs. The family Foordiceratidae is easily distinguished from the Metacoceratidae by the highly divergent flanks and the absence of an umbilical margin.</p></div>	https://treatment.plazi.org/id/03BF2F39FFA4650A707FBE698FB7FC0D	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFA7650D73CFBCA38E09FCF7.text	03BF2F39FFA7650D73CFBCA38E09FCF7.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Gzheloceratidae Ruzhencev & Shimansky 1954	<div><p>Family Gzheloceratidae Ruzhencev &amp; Shimansky, 1954</p><p>Fig. 25A</p><p>Diagnosis</p><p>Family of the superfamily Pleuronautiloidea with a rather small conch and a weakly depressed, elliptical or reniform whorl profile. Venter flattened or slightly convex; ventrolateral shoulder, flanks and umbilical margin usually broadly rounded. Sculpture with short ribs or transversely elongated nodes on the flank. Suture line with shallow lobes and low saddles. Internal lobe very shallow, without annular process (after Ruzhencev &amp; Shimansky 1954).</p><p>Included genera</p><p>Parametacoceras Miller &amp; Owen, 1934 (Bashkirian to Moscovian; 7 species).</p><p>Gzheloceras Ruzhencev &amp; Shimansky, 1954 (Gzhelian to Artinskian; 14 species).</p><p>Heurekoceras Ruzhencev &amp; Shimansky, 1954 (Artinskian; 1 species).</p><p>Celox Shimansky, 1967 (Viséan to Bashkirian; 3 species).</p><p>Pseudogzheloceras Dernov, 2021 (Bashkirian to Kasimovian; 12 species).</p><p>Remarks</p><p>The evolutionary history of the family Gzheloceratidae seems to have extended from the Viséan of the Early Carboniferous to the Early Permian, if not longer. During this long period, only few morphological changes occurred, both in the shape of the conch and in the sculpture. The species of the family show a very conservative shape of the whorl profile, which is either depressed elliptical or reniform. There is neither an angular umbilical margin nor a prominent ventrolateral shoulder developed. The sculpture consists of simple ribs or nodes on the flank (Ruzhencev &amp; Shimansky 1954).</p><p>The shape of the juvenile conch is similar to that of all other members of the superfamily Pleuronautiloidea, with the exception of the family Mosquoceratidae, which have a much larger and stouter initial conch. With an elliptical or strongly rounded trapezoidal whorl profile, the adult conch of the Mosquoceratidae has a different shape to the juvenile. Another difference from the other families is the almost straight suture line in the Gzheloceratidae .</p></div>	https://treatment.plazi.org/id/03BF2F39FFA7650D73CFBCA38E09FCF7	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFA0650D73C7BCDB89C4F95C.text	03BF2F39FFA0650D73C7BCDB89C4F95C.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Aktubonautilidae Ruzhencev & Shimansky 1954	<div><p>Family Aktubonautilidae Ruzhencev &amp; Shimansky, 1954</p><p>Fig. 25B</p><p>Diagnosis</p><p>Family of the superfamily Pleuronautiloidea with a large, stout first whorl. Whorl profile weakly depressed, semicircular or reniform. Venter, flanks and umbilical margin broadly rounded. Sculpture with lateral, transversely elongated nodes. Suture line with a shallow external, a very shallow lateral and a rather deep internal lobe; without annular process (after Ruzhencev &amp; Shimansky 1954).</p><p>Included genera</p><p>Aktubonautilus Ruzhencev &amp; Shimansky, 1954 (Artinskian; 1 species).</p><p>Basleonautilus Ruzhencev &amp; Shimansky, 1954 (Roadian; 1 species).</p><p>Remarks</p><p>The family Aktubonautilidae is closest to the Rhiphaeoceratidae; there are similarities in the shape of the conch, the course of the suture line and partly in the sculpture. However, both families differ significantly in the morphology of the juvenile conch. The Aktubonautilidae are characterised by a stout first volution, whereas the Rhiphaeoceratidae have a slender, worm-like first volution. In this respect, the Aktubonautilidae are more similar to the Mosquoceratidae; however, this family differs greatly in the type of sculpture and suture line. The sculpture is formed by lateral transverse tubercles or ribs in the Aktubonautilidae but by longitudinal oval tubercles along the ventrolateral shoulder in Mosquoceratidae . In contrast to the Mosquoceratidae, the suture line in the Aktubonautilidae has only very shallow lateral lobes.</p></div>	https://treatment.plazi.org/id/03BF2F39FFA0650D73C7BCDB89C4F95C	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFA0650C73C1B8758F36F9E7.text	03BF2F39FFA0650C73C1B8758F36F9E7.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Mosquoceratidae Ruzhencev & Shimansky 1954	<div><p>Family Mosquoceratidae Ruzhencev &amp; Shimansky, 1954</p><p>Fig. 26</p><p>Diagnosis</p><p>Family of the superfamily Pleuronautiloidea with a large, rapidly growing first whorl. Whorl profile weakly depressed, subhexagonal to trapezoidal. Venter broad, weakly convex; ventrolateral shoulder angular, flanks convex and strongly divergent; umbilical margin, if present, very weakly developed. Sculpture with ventrolateral, longitudinally elongated nodes. Suture line with a wide external, a narrower lateral and a narrow internal lobe; without annular process (after Ruzhencev &amp; Shimansky 1954).</p><p>Included genera</p><p>Mosquoceras Ruzhencev &amp; Shimansky, 1954 (Moscovian to Kungurian; 9 species).</p><p>Articheilus Ruzhencev &amp; Shimansky, 1954 (Artinskian; 1 species).</p><p>Leonardocheilus Ruzhencev &amp; Shimansky, 1954 (Kungurian; 1 species).</p><p>Remarks</p><p>According to Ruzhencev &amp; Shimansky (1954: 85), the family Mosquoceratidae is closest to Tainoceratidae (which they interpret more broadly than it is currently done). The family Mosquoceratidae differs greatly from most of the other families of the Pleuronautiloidea in the morphology of the first volution, which is large, stout and rapidly growing in the Mosquoceratidae, whereas it is smaller and, above all, much slenderer in the other families. The similarity between these families is evident in both the shape of the conch and the suture lines. There are also sculptural differences. In the Mosquoceratidae, the tubercles are longitudinally elongated and coincide exactly with the ventrolateral shoulder; in the other families, the tubercles are usually rounded conical. The species of the family Aktubonautilidae also possess a large first whorl, but differ in the shape of the whorl profile, which is semicircular or reniform with broadly rounded venter.</p></div>	https://treatment.plazi.org/id/03BF2F39FFA0650C73C1B8758F36F9E7	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFA1650F73BFB9C98907FB76.text	03BF2F39FFA1650F73BFB9C98907FB76.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Rhiphaeoceratidae Ruzhencev & Shimansky 1954	<div><p>Family Rhiphaeoceratidae Ruzhencev &amp; Shimansky, 1954</p><p>Fig. 27</p><p>Diagnosis</p><p>Family of the superfamily Pleuronautiloidea with a small, slender first whorl. Whorl profile weakly depressed, elliptical or trapezoidal. Venter broad and weakly convex, flanks convex or slightly flattened, umbilical margin broadly rounded or absent. Sculpture with short ribs on the flank. Suture line with a low external saddle, sometimes with a shallow external lobe, a very shallow lateral and a rather deep funnel-shaped internal lobe; without annular process (after Ruzhencev &amp; Shimansky 1954).</p><p>Included genera</p><p>Rhiphaeoceras Ruzhencev &amp; Shimansky, 1954 (Sakmarian to Artinskian; 2 species). Pararhiphaeoceras Ruzhencev &amp; Shimansky, 1954 (Asselian to Wuchiapingian; 5 species). Sholakoceras Ruzhencev &amp; Shimansky, 1954 (Asselian to Artinskian; 4 species).</p><p>Rhiphaeonautilus Ruzhencev &amp; Shimansky, 1954 (Artinskian; 1 species).</p><p>Eximioceras Shchedukhin, 2022 (Asselian or Sakmarian; 1 species).</p><p>New genus D to be described by Korn &amp; Ghaderi (in press) (Wuchiapingian; 2 species).</p><p>Remarks</p><p>The family Rhiphaeoceratidae can be distinguished from other Permian nautiloids by their suture line with its rather deep internal lobe. The only exceptions are the representatives of the family Aktubonautilidae, but these differ in having a much larger juvenile conch.</p></div>	https://treatment.plazi.org/id/03BF2F39FFA1650F73BFB9C98907FB76	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFA26501704BBA5B8F86FBF5.text	03BF2F39FFA26501704BBA5B8F86FBF5.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Foordiceratidae Korn 2025	<div><p>Family Foordiceratidae fam. nov.</p><p>urn:lsid:zoobank.org:act: AF7DFEF1-92F2-46BC-8A62-32D89A6BDA4A</p><p>Fig. 28</p><p>Type genus</p><p>Foordiceras Hyatt, 1893 .</p><p>Diagnosis</p><p>Family of the superfamily Tainoceratoidea with a trapezoidal whorl profile; ventrolateral shoulder rounded, flanks strongly divergent. Sculpture with ventrolateral conical nodes, sometimes with low ribs on the flank. Suture line with shallow lobes and low saddles. Internal lobe very shallow, without annular process.</p><p>Etymology</p><p>The family name refers to the type genus.</p><p>Included genera</p><p>Foordiceras Hyatt, 1893 (Wuchiapingian to Changhsingian; 8 species).</p><p>Foordoceras Girty, 1908 [nomen nullum].</p><p>Araxonautilus Shimansky, 1979 (Wordian to Wuchiapingian; 3 species).</p><p>New genus E to be described by Korn &amp; Ghaderi (in press) (Wuchiapingian to Changhsingian; 3 species).</p><p>Remarks</p><p>The repeated stratigraphic occurrence of nautiloids with an open umbilicus, a trapezoidal whorl profile and a sculpture with ventrolateral ribs or nodes in the Late Carboniferous (e.g., Latitemnocheilus), Early Permian (e.g., Pseudotemnocheilus, Articheilus) and Late Permian (e.g., Foordiceras) is a phenomenon that is not easy to explain. In order to approach this problem, four hypotheses can be discussed:</p><p>Hypothesis 1: the species of interest are a monophyletic unit descended from an ancestor with similar conch geometry and sculpture, such as the Early Carboniferous genus Temnocheilus . This may be the most parsimonious explanation in terms of morphological evolution, but it would imply a very long and simple evolutionary lineage starting in the Late Viséan and ending in the Changhsingian. It should be noted, however, that this hypothesis is mainly based on adult morphology; the juvenile conch, which is unknown in many species, plays only a minor role. For example, it is not clear whether the genera discussed also possess the characteristic bicarinate juvenile whorl profile, the longitudinal ornamentation and the deep and V-shaped inner lobe of Temnocheilus .</p><p>Sturgeon et al. (1982: 1461; 1997: 48) proposed an origin of Latitemnocheilus from Temnocheilus, because they found the longitudinal ornament characteristic for Temnocheilus also in similar development in two species of Latitemnocheilus, but not in Metacoceras . As a consequence, they concluded that “… temnocheilids were not the ancestors of, or closely related to, Metacoceras as suggested by Miller et al. (1933: p. 160), Miller &amp; Owen (1934, p. 221) and Miller &amp; Youngquist (1949, p. 94)”.</p><p>Hypothesis 2: the species compose a monophyletic unit, descended from a Late Carboniferous genus such as Metacoceras by a transformation of the inverted trapezoidal or almost rectangular whorl profile to a trapezoidal shape. This was accompanied by a regression of the angular umbilical margin. After this initial evolution, the lineage continued with only minor morphological changes throughout the Late Permian.</p><p>An origin of Latitemnocheilus from Metacoceras may be explained by the rather close resemblance of the adult morphology of these two genera, which differ mainly in the presence or absence of a pronounced umbilical margin.</p><p>Hypothesis 3: the species do not share the same phylogenetic origin; the Late Carboniferous and Permian nautiloids with trapezoidal whorl profile represent unrelated clades. In this hypothesis, the Early Permian genera such as Pseudotemnocheilus independently originated from Metacoceras or a similar genus by deflation of the umbilical margin. This scenario was proposed by Ruzhencev &amp; Shimansky (1954: 45). Dzik (1984: 160) suggested to amalgamate the Early Permian species attributed to Metacoceras and Pseudotemnocheilus by Ruzhencev &amp; Shimansky (1954) in one genus because of the minor morphological differences between the species.</p><p>Hypothesis 4: the species repeatedly descended from ancestors with a pronounced umbilical margin in the Late Carboniferous, Early Permian and Late Permian, respectively. This may be the morphologically least parsimonious solution. At the same time, it turns out that in all three cases there are morphoclines in each of the time intervals, which can be used as a good supporting argument for this hypothesis.</p><p>The ontogeny of the juvenile conch can provide solid information on the phylogenetic relationships between these species. Although the juvenile conch of the Late Permian genera is poorly known, it appears that it is more similar to the Early Permian genus Pseudotemnocheilus, with its more circular whorl profile, than to the Early Carboniferous genus Temnocheilus, which has a bicarinate juvenile conch. This may argue for an evolutionary lineage connecting the Permian groups, i.e., a descent of the Foordiceratidae from the metacoceratids.</p></div>	https://treatment.plazi.org/id/03BF2F39FFA26501704BBA5B8F86FBF5	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFAC65037069BBDC8970FCDB.text	03BF2F39FFAC65037069BBDC8970FCDB.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Pleuronautilidae Hyatt 1900	<div><p>Family Pleuronautilidae Hyatt, 1900</p><p>Fig. 29</p><p>Diagnosis</p><p>Family of the superfamily Pleuronautiloidea with a commonly subquadrate or weakly depressed whorl profile; venter ranging from convex to weakly concave, ventrolateral shoulder and umbilical margin often pronounced, flanks usually weakly convergent. Sculpture with numerous ribs on the flank, sometimes with conical tubercles and more rarely with spiral ridges. An annular process is present in the advanced species.</p><p>Included genera</p><p>New genus C to be described by Korn &amp; Hairapetian (in press) (Wordian to Changhsingian; 10 species). Pleuronautilus Mojsisovics, 1882 (Triassic).</p><p>Phloioceras Hyatt, 1884 (Triassic).</p><p>Anoploceras Hyatt, 1900 (Triassic).</p><p>Encoiloceras Hyatt, 1900 (Triassic).</p><p>Enoploceras Hyatt, 1900 (Triassic).</p><p>Holconautilus Mojsisovics, 1902 (Triassic).</p><p>Trachynautilus Mojsisovics, 1902 (Triassic).</p><p>Sibyllonautilus Diener, 1915 (Triassic).</p><p>Phaedrysmocheilus Shimansky &amp; Erlanger, 1955 (Triassic).</p><p>Arctonautilus Sobolev, 1989 (Triassic).</p><p>Grumantoceras Sobolev, 1989 (Triassic).</p><p>Remarks</p><p>Pleuronautilus is a genus that has been the subject of very different opinions in the literature over the last few decades. The genus was established by Mojsisovics (1902) for the very distinctive Triassic species Pleuronautilus trinodosus . von Arthaber (1900: 215) also used the genus name for the Late Permian forms similar to the species “ Nautilus dorso armatus ” that was described by Abich (1878) and his newly established species “ Pleuronautilus Verae ”; he considered both to be closely related.</p><p>While Miller &amp; Youngquist (1949) did not use the genus name Pleuronautilus for Permian nautilids, Kummel (1953: 34) placed 24 Permian species in this genus, together with 34 Triassic species. The reason for this high number is that Kummel also included a number of species in Pleuronautilus that had previously been placed in other genera ( Metacoceras, Foordiceras, Huanghoceras).</p><p>Ruzhencev &amp; Shimansky (1954) reduced the species composition of Pleuronautilus by accepting the genera Huanghoceras and Shansinautilus and by establishing the new genus Pseudofoordiceras for some species from the Leonard Formation of Texas, which were previously placed in the genus Metacoceras by Miller (1945) and in Foordiceras by Miller &amp; Youngquist (1949). However, Shimansky (1967) considered these three genera as being synonyms of Pleuronautilus; he listed 19 species belonging to this genus. Kummel (1964), in the Treatise on Invertebrate Paleontology, had already before synonymised the genera Huanghoceras, Shansinautilus, Tungkuanoceras, Basleonautilus and Pseudofoordiceras with Pleuronautilus .</p><p>It has already been suggested by previous authors that it is difficult to distinguish clearly between genera such as Metacoceras and Pleuronautilus in the Permian nautiloid assemblages as interpreted at that time (e.g., Kummel 1953: 34). To ensure a monophyletic definition of Pleuronautilus and related genera, it is necessary to investigate the possible phylogenetic origin of these genera and their relationships. It also needs to be clarified whether species with Pleuronautilus -like conch morphology and sculpture, such as the recently described Late Permian Serometacoceras and Lutonautilus, could have evolved independently during the Permian.</p><p>Earlier authors had already considered that, starting from the putative ancestral genus Metacoceras, lateral branches with strengthened sculpture gave rise to several genera with coarse sculpture, such as Huanghoceras from the Taiyuan Series of North China (Yin 1933) and Pseudofoordiceras from the Leonard Formation of Texas (Ruzhencev &amp; Shimansky 1954). Apparently, such considerations have not yet been made for the Late Permian species of the Transcaucasus. Both Shimansky (1965) and Teichert &amp; Kummel (1973) assigned the species of this group of species to the two genera Metacoceras and Pleuronautilus . Such a practice would imply that the latter genus actually has a Late Permian origin. However, the empirical data is hardly sufficient for such a statement.</p><p>Here, the family Pleuronautilidae is reduced in its content to the Triassic species, which share some morphological characteristics, such as the rather dense transverse ribbing. Furthermore, they could be united by the presence of an annular process of the suture line, which means that they have a dorsal inflexion of the septum.</p><p>There are some Late Permian species that have a very similar shell and sculpture to Pleuronautilus, but the apparent lack the annular process. These will shortly be described as new genus C by Korn &amp; Hairapetian (in press) and may be the ancestors of the Triassic pleuronautilids.</p></div>	https://treatment.plazi.org/id/03BF2F39FFAC65037069BBDC8970FCDB	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFAE65037025BCEE8CF1F95D.text	03BF2F39FFAE65037025BCEE8CF1F95D.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Tainoceratoidea Hyatt 1883	<div><p>Superfamily Tainoceratoidea Hyatt, 1883</p><p>Diagnosis</p><p>Superfamily of the suborder Tainoceratina with a discoidal to pachyconic, subinvolute or subevolute conch. Whorl profile always with midventral longitudinal groove; in early species subquadrate with a distinct ventrolateral shoulder and a distinct umbilical margin, in derived species polygonal with divergent or convergent flanks. Dorsal whorl zone always very small. Sculpture with rows of ventrolateral nodes, in some species with rows of nodes on the flank. Septa simply domed; suture line depending on the whorl profile, usually with shallow lobes and low saddles.</p><p>Included family</p><p>Tainoceratidae Hyatt, 1883 (Late Carboniferous to Early Triassic; 23 Palaeozoic genera, 89 Palaeozoic species).</p><p>Remarks</p><p>The superfamily Tainoceratoidea as used here corresponds to the family Tainoceratidae as employed by earlier authors. It is generally regarded as one of the most important Late Carboniferous to Triassic nautiloid clades. Its family composition and internal classification have been discussed repeatedly over the last 90 years, and various concepts for the differentiation of the genera have been presented. As many of the other families of the suborder are placed within the Pleuronautiloidea, only one family is accepted here:</p><p>Tainoceratidae Hyatt, 1883 – Forms with usually octagonal whorl profile; sculpture usually with several rows of nodes (Fig. 30).</p></div>	https://treatment.plazi.org/id/03BF2F39FFAE65037025BCEE8CF1F95D	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFAE65057043B875885EF904.text	03BF2F39FFAE65057043B875885EF904.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Tainoceratidae Hyatt 1883	<div><p>Family Tainoceratidae Hyatt, 1883</p><p>Fig. 30</p><p>Diagnosis</p><p>Family of the superfamily Tainoceratoidea with a discoidal to pachyconic, subinvolute or subevolute conch. Whorl profile always with midventral longitudinal groove; in early species subquadrate with a distinct ventrolateral shoulder and a distinct umbilical margin, in derived species polygonal with divergent or convergent flanks. Dorsal whorl zone always very small. Sculpture with rows of ventrolateral nodes, in some species with rows of nodes on the flank. Septa simply domed; suture line depending on the whorl profile, usually with shallow lobes and low saddles.</p><p>Included genera</p><p>Tainoceras Hyatt, 1883 (Kasimovian to Changhsingian; 41 species).</p><p>Tainionautilus Mojsisovics, 1902 (Wuchiapingian to Early Triassic; 6 species).</p><p>Tirolonautilus Mojsisovics, 1902 (Changhsingian; 8 species).</p><p>Tylonautilus Pringle &amp; Jackson, 1928 (Serpukhovian to Bashkirian; 6 species).</p><p>Aulametacoceras Miller &amp; Unklesbay, 1942 (Roadian; 2 species).</p><p>Hexagonites Hayasaka, 1947 (Permian; 1 species)?</p><p>Hunanoceras Chao, 1954 (Roadian; 1 species).</p><p>Hefengnautilus Xu, 1977 (Roadian; 1 species).</p><p>Clavinautilus Zhao, Liang &amp; Zheng, 1978 (Changhsingian; 1 species).</p><p>Eulomacoceras Zhao, Liang &amp; Zheng, 1978 (Wuchiapingian; 3 species).</p><p>Lirometacoceras Zhao, Liang &amp; Zheng, 1978 (Changhsingian; 1 species).</p><p>Neotainoceras Zhao, Liang &amp; Zheng, 1978 (Changhsingian; 5 species).</p><p>Paratainonautilus Zhao, Liang &amp; Zheng, 1978 (Changhsingian; 1 species).</p><p>Seironautilus Zhao, Liang &amp; Zheng, 1978 (Wuchiapingian; 1 species).</p><p>Neoclavinautilus Liang, 1984 (Changhsingian; 1 species).</p><p>Nodonautilus Liang, 1984 (Wuchiapingian; 1 species).</p><p>? Aulagonoceras Zheng, 1984 (Changhsingian; 4 species).</p><p>Nodopleuroceras Zheng, 1984 (Changhsingian; 2 species).</p><p>Meixianlingites Qin, 1986 (Wuchiapingian; 1 species).</p><p>Paratainoceras Qin, 1986 (Wuchiapingian; 1 species).</p><p>Siamnautilus Ishibashi et al., 1994 (Changhsingian; 1 species).</p><p>Gujiaonautilus Miao et al., 2019 (Changhsingian; 1 species).</p><p>New genus F to be described by Korn &amp; Ghaderi (in press) (Wuchiapingian; 1 species).</p><p>New genus D to be described by Korn &amp; Hairapetian (in press) (Wuchiapingian; 2 species).</p><p>Remarks</p><p>The Tainoceratidae are a fairly well-defined family characterised by the presence of a prominent midventral groove; most of the species possess at least two rows of ventral or ventrolateral nodes. Additional rows of nodes may be developed on the flanks and ventrolateral shoulder. However, there is a reduction in the number of nodes in some derived Late Permian genera.</p><p>Ruzhencev &amp; Shimansky (1954) stated that Tainoceras appears to be derived from Metacoceras . An argument in favour of this hypothesis could be the stratigraphic co-occurrence of the oldest species of the two genera in Late Carboniferous cephalopod assemblages. However, this hypothesis implies a significant leap in morphological evolution towards Tainoceras . It should be noted that Metacoceras and related genera usually have inverted trapezoidal or rectangular whorl profiles, in contrast to the polygonal whorl profiles of Tainoceras . Metacoceras and its close relatives also lack a midventral groove. Finally, Metacoceras does not have a sculpture with rows of nodes on the venter; the sculpture elements are restricted to the flanks.</p><p>The family Tainoceratidae became diverse in the latest Carboniferous Gzhelian stage, when the single genus Tainoceras was geographically widespread with a number of species (e.g., Sturgeon et al. 1982, 1997). The family persisted with this single genus throughout most of the Permian (e.g., Miller et al. 1933; Miller &amp; Unklesbay 1942; Miller &amp; Youngquist 1949). It continued into the Late Permian, when a large number of new species had evolved, particularly in the Late Permian shelf seas of southern China. To date, more than twelve tainoceratid genera have been described from this single region (Chao 1954; Xu 1977; Zhao et al. 1978; Liang 1984; Zheng 1984; Qin 1986; Miao et al. 2021). This is far more than in any other region where tainoceratids occur at the same time, such as Europe with the Dolomites (Prinoth &amp; Posenato 2007), the Bűkk Mountains (Schréter 1974) and Serbia (Simić 1933). Transcaucasia (Korn &amp; Ghaderi in press) and central Iran (Korn &amp; Hairapetian in press) are also relatively poor in tainoceratids compared to southern China.</p><p>There is a very asymmetric distribution of species composing the genera of the family Tainoceratidae . Of the 22 genera, 14 are monospecific and four have two or three previously known species. The most species-rich genera Tainoceras (41 species), Tirolonautilus (8 species) and Tainionautilus (6 species) are, interestingly or significantly, the first described genera of the family (Hyatt 1883 –1884; Mojsisovics 1902).</p></div>	https://treatment.plazi.org/id/03BF2F39FFAE65057043B875885EF904	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFA865067045B9AD8FF9F9D1.text	03BF2F39FFA865067045B9AD8FF9F9D1.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Liroceratina Flower 1955	<div><p>Suborder Liroceratina Flower, 1955</p><p>Fig. 31</p><p>Diagnosis</p><p>Suborder of the order Nautilida, in which an umbilical margin is formed early in ontogeny; advanced species may regress this character. Conch usually pachyconic and rarely discoidal or globular, subinvolute to involute. Juvenile whorl profile circular. Adult whorl profile usually circular or depressed oval without distinct ventrolateral shoulder in the early species, showing modifications during evolution (inverted trapezoidal with convergent flanks and flattened venter). Dorsal whorl zone always present, small to moderately deep. Juvenile sculpture with spiral lines that may be restricted to the umbilical area in the early species; adult sculpture usually lacking except for spiral lines in some species. Septa simply domed in the early species, with dorsal inflexion in advanced species and with corrugated septa in two derived clades. Suture line depending on the whorl profile, usually with shallow lobes and low saddles, with distinct lobes in two clades. Siphuncle in central or subcentral position.</p><p>Included superfamilies</p><p>Liroceratoidea Miller &amp; Youngquist, 1949 (Early Carboniferous to Late Triassic; 23 Palaeozoic genera, 142 Palaeozoic species).</p><p>Ephippioceratoidea Miller &amp; Youngquist, 1949 (Early Carboniferous to Early Permian; 3 genera, 26 species).</p><p>Clydonautiloidea Hyatt, 1900 (Middle to Late Triassic).</p><p>Remarks</p><p>Taxonomy</p><p>The suborder Liroceratina was interpreted by Shimansky (1957) as consisting of the superfamily Lirocerataceae Miller &amp; Youngquist, 1949 with the mostly Palaeozoic families Koninckioceratidae, Liroceratidae Miller &amp; Youngquist, 1949, Ephippioceratidae Miller &amp; Youngquist, 1949 and Paranautilidae Kummel in Flower &amp; Kummel, 1950 and the fully Mesozoic superfamily Clydonautiloidea Hyatt, 1900 . Kummel (1964) included the families Liroceratidae, Ephippioceratidae, Clydonautilidae, Gonionautilidae Kummel in Flower &amp; Kummel, 1950 and Siberionautilidae Popov, 1951 in his superfamily Clydonautilaceae .</p><p>Morphology and subdivision</p><p>Almost all Carboniferous and Permian genera of the suborder Liroceratina, which all belong to the superfamilies Liroceratoidea and Ephippioceratoidea, are easily recognised by their stout, narrowly umbilicate conch. All have either a very simple, almost straight suture line ( Liroceratoidea) or a suture line with a high ventral saddle ( Ephippioceratoidea). Only the Triassic descendants (superfamily Clydonautiloidea) show a modification of the conch by lateral compression and complete closure of the umbilicus. These species show a complication of the suture line with the formation of lateral lobes; they are the nautiloids with the most complex suture lines.</p><p>The suborder Liroceratina represents a large group of species that differ in their conch morphology from the other nautiloid suborders of the Late Palaeozoic and Triassic. The liroceratids are predominantly pachyconic or globular with a narrow or completely closed umbilicus (Fig. 31). The whorl profile is usually reniform, the flanks and venter often merging into a more or less uniformly convex arch. In stratigraphically older genera (e.g., Bistrialites Turner, 1954, Liroceras) the umbilical margin is usually uniformly rounded and the umbilical wall convex; in derived species the umbilical margin may be subangular and the umbilical wall flattened. Some derived genera ( Coelogasteroceras Hyatt, 1893, Permonautilus Kruglov, 1933 and members of the Clydonautiloidea) show a longitudinal depression on the venter or a galeate form ( Callaionautilus Kieslinger, 1924).</p><p>The suborder Liroceratina consists of three superfamilies, which differ mainly in the morphological evolution of the septal shape and the suture lines:</p><p>Liroceratoidea . – Forms with a simple suture line extending almost straight across the umbilical wall, the flanks and the venter. The dorsal suture is also usually almost straight. Some genera (e.g., Paranautilus Mojsisovics, 1902) have an annular process, but this may occur only intermittently during ontogeny (Sobolev 1989: 18).</p><p>Ephippioceratoidea . – Forms with a highly elevated ventral saddle created by a striking division of the septal surface by a prominent ventrodorsal ridge into two broadly arched domes.</p><p>Clydonautiloidea . – Forms with a highly elevated ventral saddle, which is flat ( Styrionautilus Mojsisovics, 1902) or divided by an external lobe ( Proclydonautilus Mojsisovics, 1902). There may be several secondary external lobes ( Siberionautilus Popov, 1951) or extensive separation of the entire suture line ( Yakutionautilus Arkhipov &amp; Barskov, 1970) (Arkhipov &amp; Barskov 1970; Sobolev 1989). The internal lobe is shallow; an annular process may be present.</p><p>Origin</p><p>The liroceratids were considered by Flower &amp; Kummel (1950) to be the basal representatives of the order Nautilida (corresponding to the suborder Nautilina in current understanding), which, like the three other nautiloid orders of the Carboniferous and Permian accepted by them, should have originated in the Devonian family Barrandeoceratidae Foerste, 1925 . Shimansky (1957) derived the suborder Liroceratina (as he used it) from the Devonian family Litogyroceratidae Shimansky, 1957 (suborder Rutoceratina). Kummel (1964) also saw the origin of his superfamily Clydonautilaceae (which corresponds to the Liroceratina of Shimansky) in the Devonian; he assumed that the group originated from the order Oncocerida Flower.</p><p>The assumption that the liroceratids originated in the Devonian is probably based on the problematic genus Potoceras Hyatt, 1894 . The only species, P. dubium Hyatt, 1894, was based on a single specimen that was poorly illustrated by Hyatt. Kummel (1963) gave a detailed description and a good photographic illustration of the holotype. Hyatt (1894: 538) did not know the provenance or stratigraphic position of the specimen and believed it to be Devonian. This was confirmed by Charles Schuchert, who suggested the Iberg in the Harz Mountains as the locality, based on a spiriferid brachiopod attached to the nautilid. Kummel (1963: 356) had this information checked by G.A. Cooper, who concluded that it was probably a Viséan brachiopod. If the specimen indeed comes from the Iberg, which is by no means certain, it could actually be a specimen from the well-known Early Carboniferous Neptunian dykes, in which cephalopods and spiriferids have been identified (e.g., Schindewolf 1951).</p><p>The conch morphology of the holotype of Potoceras dubium is very similar to the typical Early Carboniferous representatives of Liroceras or Bistrialites, such as those described by Foord (1891) and Turner (1954) from northern England, by Trenkner (1868) and Schmidt (1951) from the Harz Mountains, and by Korn &amp; Klug (2023) from the Anti-Atlas of Morocco. For this reason, too, it is reasonable to assume that the stratigraphic age of Potoceras dubium is Early Carboniferous. Potoceras may even be a senior synonym of Bistrialites or Liroceras, but this problem cannot be solved at present because of the limited data available.</p><p>Dzik (1984: 168) proposed a fundamentally different hypothesis in which the family Liroceratidae (which he defined more broadly than the other authors) was derived from an Early Carboniferous group of nautilids, that is the family Trigonoceratidae . He based this hypothesis on the juvenile ornament with spiral ridges present in both Liroceras and Vestinautilus and postulated that both genera were related through Bistrialites Turner, 1954 . There are several reasons for accepting this suggestion. An evolution from Vestinautilus to Liroceras would mainly involve a narrowing of the umbilicus, although this would be mainly due to an expansion of the ventral zone (Fig. 3E, J). Therefore, the spiral ridges are still located in the area of the (topographic) ventrolateral shoulder in Vestinautilus, in the middle of the flank in Bistrialites and in the (topographic) umbilical margin in Liroceras .</p><p>Phylogeny</p><p>Several scenarios have been developed to clarify the phylogeny within the liroceratids. Shimansky (1957, 1962) proposed three independent evolutionary lineages, the first of which ( Koninckioceratidae) is placed here in the suborder Temnocheilina . The superfamily Clydonautilaceae was derived from the Lirocerataceae by Shimansky. This phylogenetic scheme was supported by Kummel (1964).</p><p>Descendants</p><p>Flower &amp; Kummel (1950) linked, albeit with a question mark, the families that are now considered part of the suborder Nautilina Agassiz, 1847 (e.g., Nautilidae de Blainville, 1825, Aturiidae Chapman, 1857) to the family Paranautilidae, which they accepted as valid. This view was not shared by later authors (Shimansky 1962; Kummel 1964; Dzik 1984).</p></div>	https://treatment.plazi.org/id/03BF2F39FFA865067045B9AD8FF9F9D1	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFAB657973CAB9FB8C0DFBC3.text	03BF2F39FFAB657973CAB9FB8C0DFBC3.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Liroceratoidea Miller & Youngquist 1949	<div><p>Superfamily Liroceratoidea Miller &amp; Youngquist, 1949</p><p>Diagnosis</p><p>Superfamily of the suborder Liroceratina with a pachyconic and rarely discoidal or globular, subinvolute to involute conch. Whorl profile usually circular or depressed oval without distinct ventrolateral shoulder; in some species with a pronounced but rounded ventrolateral shoulder. Dorsal whorl zone usually small to moderately deep. Juvenile sculpture in the early species with spiral lines that may be restricted to the umbilical area; derived species are often smooth. Suture line very simple, almost straight across flanks and venter.</p><p>Included families</p><p>Liroceratidae Miller &amp; Youngquist, 1949 (Early Carboniferous to Late Permian; 17 Palaeozoic genera, 118 Palaeozoic species).</p><p>Coloceratidae Hyatt, 1893 [homonym; synonym of Liroceratidae Miller &amp; Youngquist, 1949].</p><p>Paranautilidae Kummel in Flower &amp; Kummel, 1950 (Early to Late Triassic).</p><p>Permonautilidae Barskov &amp; Shilovsky, 2014 (Middle to Late Permian; 1 genus, 10 species).</p><p>Planetoceratidae fam. nov. (Early to Late Carboniferous; 1 genus, 9 species).</p><p>New family to be described by Korn &amp; Ghaderi (in press) (Late Permian; 3 genera, 5 species).</p><p>Remarks</p><p>The species of the Liroceratoidea can easily be distinguished from the species of the other superfamilies of the Liroceratina by the simple septal shape and thus the very simple, almost straight suture line.</p><p>The Palaeozoic families are characterised as follows:</p><p>Liroceratidae Miller &amp; Youngquist, 1949 – Ancestral forms with involute or subinvolute conch, umbilical wall usually rounded (Fig. 32).</p><p>Planetoceratidae fam. nov. – Ancestral forms, in which the terminal whorl detaches from the preceding whorl (Fig. 33).</p><p>Permonautilidae Barskov &amp; Shilovsky, 2014 – Advanced forms, which possess a prominent thorn-like umbilical process in the adult stage (Fig. 34).</p><p>New family to be described by Korn &amp; Ghaderi (in press) – Ancestral forms with a pronounced umbilical margin and a flattened umbilical wall; the venter has the tendency to become flattened or weakly concave (Fig. 35).</p></div>	https://treatment.plazi.org/id/03BF2F39FFAB657973CAB9FB8C0DFBC3	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFD4657B73F0BBE38E7FFD9F.text	03BF2F39FFD4657B73F0BBE38E7FFD9F.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Liroceratidae Miller & Youngquist 1949	<div><p>Family Liroceratidae Miller &amp; Youngquist, 1949</p><p>Fig. 32</p><p>Diagnosis</p><p>Family of the superfamily Liroceratoidea with a usually pachyconic or globular, subinvolute to subevolute conch. Whorl profile in the adult stage usually more or less strongly depressed; flanks and venter form a continuous arch in the early species, the venter can be flattened or concave in advanced species. Umbilical margin rounded; umbilical wall usually convex. Ornament usually consisting of fine growth lines; spiral lines occur in some genera. Septum simple in shape, concavely domed; suture line very simple, almost straight across flanks and venter or with small lobes and saddles.</p><p>Included genera</p><p>Solenoceras Hyatt, 1884 [homonym of Solenoceras Conrad, 1860; objective synonym of Coelogasteroceras].</p><p>Coelogasteroceras Hyatt, 1893 (Bashkirian to Changhsingian; 11 species).</p><p>Coloceras Hyatt, 1893 [homonym of Coloceras Taschenberg, 1882; synonym of Liroceras].</p><p>Stearoceras Hyatt, 1893 (Serpukhovian to Changhsingian; 10 species).</p><p>Peripetoceras Hyatt, 1894 (Serpukhovian to Changhsingian; 22 species).</p><p>Potoceras Hyatt, 1894 (? Viséan; 1 species).</p><p>Nannoceras Hyatt, 1894 [nomen nullum; synonym of Peripetoceras].</p><p>Conradiceras Cossmann, 1900 [objective synonym of Coelogasteroceras].</p><p>Cyclonautilus Hind, 1910 [synonym of Peripetoceras].</p><p>Liroceras Teichert, 1940 (Viséan to Changhsingian; 47 species).</p><p>Condraoceras Miller, Lane &amp; Unklesbay, 1947 (Kasimovian to Artinskian; 3 species).</p><p>Periptoceras Chao, 1954 [nomen nullum; synonym of Peripetoceras].</p><p>Hemiliroceras Ruzhencev &amp; Shimansky, 1954 (Bashkirian to Artinskian; 6 species).</p><p>Bistrialites Turner, 1954 (Viséan to Serpukhovian; 5 species).</p><p>Pseudophacoceras Turner, 1966 (? Viséan; 1 species).</p><p>Neobistrialites Tucker, Mapes &amp; Aronoff, 1978 (Moscovian; 1 species).</p><p>Jianoceras Ma, 1997 (Permian; 1 species).</p><p>Nemdoceras Barskov &amp; Shilovsky, 2014 (Roadian; 3 species).</p><p>Paraliroceras Barskov &amp; Shilovsky, 2014 (Roadian to Changhsingian; 2 species).</p><p>Tatianautilus Barskov &amp; Shilovsky, 2014 (Roadian; 1 species).</p><p>Leniceras Leonova &amp; Shchedukhin, 2020 (Asselian or Sakmarian; 1 species).</p><p>Shikhanonautilus Leonova &amp; Shchedukhin, 2020 (Asselian or Sakmarian; 1 species).</p><p>Thyoceras Leonova &amp; Shchedukhin, 2020 (Asselian or Sakmarian; 1 species).</p><p>New genus G to be described by Korn &amp; Ghaderi (in press) (Wuchiapingian; 1 species).</p><p>Perunautilus Crick &amp; Sobolev, 1994 (Triassic).</p><p>Tomponautilus Sobolev, 1989 (Triassic).</p><p>Remarks</p><p>The Liroceratidae are probably the family with the longest stratigraphic range among the Palaeozoic Nautilida, extending from the Early Carboniferous to the Triassic. It can be regarded as a morphologically very stable clade in which morphological changes occurred only very rarely. Some of the new morphological developments have been separated as independent families ( Permonautilidae, Paranautilidae), so that the Liroceratidae represent the conservative stem group.</p><p>The distribution of species among the 18 Palaeozoic genera within the Liroceratidae shows a very asymmetric picture. Nine genera are represented by only one species, while Liroceras and Peripetoceras are very diverse with 47 and 22 species, respectively. In addition, many species are known from only one specimen. As with many other groups of Nautilida, a revision is necessary and will probably change the picture so that fewer genera and species can be accepted.</p></div>	https://treatment.plazi.org/id/03BF2F39FFD4657B73F0BBE38E7FFD9F	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFD6657A704CBD328C74FC3F.text	03BF2F39FFD6657A704CBD328C74FC3F.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Planetoceratidae Korn 2025	<div><p>Family Planetoceratidae fam. nov.</p><p>urn:lsid:zoobank.org:act: F919D8AF-4002-4CFE-BD02-0E8CFFC2EE66</p><p>Fig. 33</p><p>Type genus</p><p>Planetoceras Hyatt, 1893 .</p><p>Diagnosis</p><p>Family of the superfamily Liroceratoidea with a pachyconic, usually subinvolute conch; the terminal portion of the conch is detached from the preceding whorl. Whorl profile in the adult stage usually more or less strongly depressed; flanks and venter form a continuous arch, umbilical margin pronounced, umbilical all flat and steep. Ornament consisting of fine growth lines. Septum simple in shape, concavely domed; suture line very simple, almost straight across flanks and venter or with small lobes and saddles.</p><p>Etymology</p><p>The family name refers to the type genus.</p><p>Included genus</p><p>Planetoceras Hyatt, 1893 (Tournaisian to Kasimovian; 9 species).</p><p>Remarks</p><p>The placement of Planetoceras was problematic. Planetoceras retardatum Hyatt, 1893 and P. globatum (Sowerby, 1824) from early Late Tournaisian limestones of Belgium and Ireland have a peculiar conch morphology with a terminal whorl, which is depressed and oval in profile, and is detached from the preceding whorl. It is not possible to conclude whether the detached final volution in Planetoceras is due to increased coiling or secondary uncoiling.</p><p>Contrary to previous authors, a separate family is established for the genus Planetoceras and it is placed in the superfamily Liroceratoidea . Kummel (1964) placed Planetoceras in the then very heterogeneous family Koninckioceratidae . Shimansky (1967) also placed it together with the genera Millkoninckioceras and Lophoceras in the family Koninckioceratidae, which consisted of only three genera.</p><p>The shape of the inner volutions and their sculpture argue against placement in the Koninckioceratidae . Planetoceras has a distinct umbilical margin, with some coarse longitudinal ridges, giving it a morphology that is much closer to that of early liroceratids. Another common feature with the liroceratids is the expansion of the flank and venter area. In contrast to liroceratids, the umbilical wall of Planetoceras is flattened and steep. However, the most important distinguishing feature is the detachment of the adult whorl spiral.</p></div>	https://treatment.plazi.org/id/03BF2F39FFD6657A704CBD328C74FC3F	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFD7657D73DABC8F89A2FC7F.text	03BF2F39FFD7657D73DABC8F89A2FC7F.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Permonautilidae Barskov & Shilovsky 2014	<div><p>Family Permonautilidae Barskov &amp; Shilovsky, 2014</p><p>Fig. 34</p><p>Diagnosis</p><p>Family of the superfamily Liroceratoidea with a pachyconic or globular, usually subinvolute to subevolute conch. Whorl profile in the adult stage usually more or less strongly depressed; flanks and venter form a continuous arch in the early forms, the venter can be flattened or concave in advanced forms. Terminal aperture with long lateral shell processes emerging from the umbilical margin. Ornament consisting of fine or coarse growth lines. Septum simple in shape, concavely domed; suture line very simple, almost straight across flanks and venter or with small lobes and saddles.</p><p>Included genera</p><p>Permonautilus Kruglov, 1933 (Roadian to Wuchiapingian; 10 species).</p><p>Alexandronautilus Shimansky, 1962 [synonym of Permonautilus Kruglov, 1933].</p><p>Remarks</p><p>The family Permonautilidae was introduced by Barskov &amp; Shilovsky in Barskov et al. (2014) on the basis of virtually one character to separate it from the Liroceratidae, namely the presence of long lateral shell processes emerging from the umbilical margin. Such a process is apparently absent in the other genera of the superfamily Liroceratoidea . Very similar processes are only known from the family Solenochilidae (suborder Solenochilina), which is not related to the Permonautilidae . Barskov &amp; Shilovsky in Barskov et al. (2014: 1391) clarified that the Permonautilidae are separated from the Solenochilidae by the position of the siphuncle, which is subcentral or centrodorsal in the Permoceratidae and subventral in the Solenochilidae .</p><p>The occurrence of the long shell processes in the Early to Late Carboniferous Solenochilidae and the Middle to Late Permian Permonautilidae is indeed a very interesting phenomenon, as both families belong to two unrelated evolutionary lineages that were probably separated already in the Devonian (Dzik 1984). Although the distinction between the two families Liroceratidae and Permonautilidae is based on only one character, the separation is still accepted here with reservations.</p></div>	https://treatment.plazi.org/id/03BF2F39FFD7657D73DABC8F89A2FC7F	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFD1657C73B5BBE28C48F99E.text	03BF2F39FFD1657C73B5BBE28C48F99E.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Ephippioceratoidea Miller & Youngquist 1949	<div><p>Superfamily Ephippioceratoidea Miller &amp; Youngquist, 1949</p><p>Diagnosis</p><p>Superfamily of the suborder Liroceratina with a pachyconic or globular, involute to subinvolute conch. Whorl profile in the adult stage usually more or less strongly depressed; flanks and venter form a continuous arch. Ornament usually consisting of fine growth lines; some species have spiral lines or fine ribs. Septum strikingly bilobate; suture line with high external saddle.</p><p>Included family</p><p>Ephippioceratidae Miller &amp; Youngquist, 1949 (Early Carboniferous to Early Permian; 3 genera, 26 species).</p></div>	https://treatment.plazi.org/id/03BF2F39FFD1657C73B5BBE28C48F99E	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFD1657F73D2B935885EFC72.text	03BF2F39FFD1657F73D2B935885EFC72.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Ephippioceratidae Miller & Youngquist 1949	<div><p>Family Ephippioceratidae Miller &amp; Youngquist, 1949</p><p>Fig. 36</p><p>Diagnosis</p><p>Family of the superfamily Ephippioceratoidea with a pachyconic or globular, involute to subinvolute conch. Whorl profile in the adult stage usually more or less strongly depressed; flanks and venter form a continuous arch. Ornament usually consisting of fine growth lines; some species have spiral lines or fine ribs. Septum strikingly bilobate; suture line with high external saddle.</p><p>Included genera</p><p>Ephippioceras Hyatt, 1894 (Viséan to Roadian; 16 species).</p><p>Megaglossoceras Miller, Dunbar &amp; Condra, 1933 (Bashkirian to Asselian; 9 species).</p><p>Arthuroceras Shimansky, 1962 (Bashkirian; 1 species).</p><p>Remarks</p><p>The composition of the family Ephippioceratidae proposed here agrees with that outlined by Shimansky (1962) and Kummel (1964), while Dzik (1984) included the genera Ephippioceras and Megaglossoceras, together with Styrionautilus and others, in the family Liroceratidae .</p><p>The members of the family Ephippioceratidae cannot be confused with other nautiloids if the shape of the septa is preserved. Ephippioceras and Megaglossoceras are characterised by a very conspicuous bilobate septal surface, the peculiar shape of which is produced by a high ventrodorsal ridge dividing the entire septum (Fig. 36). There are apparently no known species that could be considered as intermediates between Bistrialites or Liroceras and Ephippioceras .</p><p>Dzik (1984: 169) discussed the origin of Ephippioceras and suggested Stearoceras as a possible ancestor. The reason for this suggestion was that the suture line of Stearoceras has a ventral undulation, which may have developed into the conspicuous external saddle. According to Dzik (1984), Ephippioceras gave rise to Megaglossoceras, which is the ancestor of the Triassic genus Styrionautilus . This assumption is based on the superficially similar sutures with a ventral saddle. However, it overlooks the fact that the ventral saddle in Ephippioceras and Megaglossoceras was produced by the bilobate deformation of the entire septum by a high ridge, which is not present in Clydonautilus Mojsisovics, 1882 and related genera. Therefore, a phylogenetic lineage from the Liroceratidae to the Clydonautilidae is preferred here.</p></div>	https://treatment.plazi.org/id/03BF2F39FFD1657F73D2B935885EFC72	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFD36571703EBE698EA9FDBB.text	03BF2F39FFD36571703EBE698EA9FDBB.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Solenochilina Flower 1950	<div><p>Suborder Solenochilina Flower, 1950</p><p>Diagnosis</p><p>Suborder of the order Nautilida, in which the conch form ranges from cyrtoconic, gyroconic to nearly involute with extraordinarily high coiling rate. Dorsal whorl zone missing or very small. Shell surface usually smooth. Suture line nearly straight with a small external lobe. Siphuncle in marginal ventral position.</p><p>Included superfamilies</p><p>Aipoceratoidea Hyatt, 1884 (Early Carboniferous to Early Permian; 7 genera, 54 species). Scyphoceratoidea Ruzhencev &amp; Shimansky, 1954 (Early Carboniferous to Early Permian; 9 genera, 23 species).</p><p>Remarks</p><p>Taxonomy</p><p>The position of the solenochilids within the order Nautilida has been very unstable over the decades, with different authors expressing sometimes very different opinions. Flower &amp; Kummel (1950) presented them as an isolated order Solenochilida, derived (with a question mark) from the family Barrandeoceratidae Foerste, 1925 .</p><p>Shimansky (1957) placed the superfamily Solenochilaceae, to which he included the families Litogyroceratidae Shimansky, 1957, Scyphoceratidae, Dentoceratidae and Solenochilidae, in the suborder Rutoceratina . Later, Shimansky (1962, 1967) modified this scheme only in the minor detail of giving priority to the names Aipoceratidae and Aipocerataceae over the names Solenochilidae and Solenochilaceae .</p><p>Furnish &amp; Glenister (in Kummel 1964: K440) interpreted the superfamily Aipocerataceae, to which they assigned the families Aipoceratidae, Solenochilidae and Scyphoceratidae, as an independent evolutionary lineage, which possibly derived from the superfamily Tainocerataceae (Kummel 1964: K385).</p><p>Dzik (1984) considered the families Aipoceratidae and Solenochilidae to belong to an uncertain suborder. He suppressed the family Scyphoceratidae that was recognised by the other authors and placed the genera belonging to it in the orthoceratid family Cycloceratidae Hyatt, 1900 (Dzik 1984: 130).</p><p>Due to the lack of new information, little can be contributed here to the two competing systematic interpretations. However, on the basis of the somewhat marginal position of the siphuncle, the family Scyphoceratidae is provisionally retained in the suborder Solenochilina .</p><p>Morphology and subdivision</p><p>The suborder Solenochilina is characterised by two main features, which are the ventrally located siphuncle and the very high coiling rate. Two superfamilies are recognised here:</p><p>Aipoceratoidea Hyatt, 1884 . – Conch cyrtoconic, gyroceraconic to subinvolute or involute, pachyconic to globular with a very mall whorl overlap zone.</p><p>Scyphoceratoidea Ruzhencev &amp; Shimansky, 1954 . – Conch from nearly orthoconic to cyrtoconic.</p><p>Phylogeny</p><p>The origin of the suborder Solenochilina has been discussed several times in the literature and cannot yet be considered sufficiently resolved. Flower (1955: 256) interpreted all Carboniferous coiled nautiloids as derived from rutoceratids and explicitly included the solenochilids: “Probably the small Late Paleozoic order the Solenochilida has its origin also in the Rutoceratida”. This concept was supported by Shimansky (1957, 1962, 1967), Kummel (1964) and Flower (1964: 5). Flower (1964: 12), however, stated that the solenochilids were “almost certainly” allied to the order Oncoceratida .</p><p>Dzik (1984: 156) was not sure whether the two families, Aipoceratidae and Solenochilidae, were phylogenetically related and suggested the Devonian genera Geitonoceras Zhuravleva, 1974 and Cranoceras Hyatt, 1884 as possible ancestors. According to Dzik (1984: 157), the data suggest that solenochilids “... are much more closely related to the Oncoceratidae than to the Nautilida ”. But at the same time, he suggested that “... it is more reasonable to retain the Aipocerataceae in the Nautilida until their systematic position is known”. That view is shared here.</p></div>	https://treatment.plazi.org/id/03BF2F39FFD36571703EBE698EA9FDBB	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFDC65707020BD0E8CE0FC77.text	03BF2F39FFDC65707020BD0E8CE0FC77.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Aipoceratoidea Hyatt 1884	<div><p>Superfamily Aipoceratoidea Hyatt, 1884</p><p>Fig. 37</p><p>Diagnosis</p><p>Superfamily of the suborder Solenochilina, in which the conch form ranges from gyroconic to nearly involute with extraordinarily high coiling rate. Whorl profile laterally compressed to weakly depressed.</p><p>Included families</p><p>Aipoceratidae Hyatt, 1884 (Early Carboniferous to Early Permian; Permian; 5 genera, 18 species). Solenochilidae Hyatt, 1893 (Early Carboniferous to Middle Permian; 2 genera, 36 species).</p><p>Remarks</p><p>A very apt characterisation of the superfamily Aipoceratoidea was given by Shimansky (1967: 39) (translated from Russian): “The origin of the peculiar Late Palaeozoic nautiloids, grouped in the superfamily Aipocerataceae and characterised by a smooth conch of various shapes, a ventral position of the siphuncle and an almost straight suture line, is not very clear. There seems to be no doubt about the unity of the group, even though its representatives differ greatly in the shape of their conchs. Some have conchs with completely free whorls ( Aipoceras), others with touching whorls ( Asymptoceras) and others with slightly overlapping whorls ( Solenochilus). In most representatives, the shell rapidly increases in width and height, sometimes becoming almost spherical ( Solenochilus, Acanthonautilus) and forming lateral ear-like projections (Fig. 37). American authors differentiate between the families Aipoceratidae and Solenochilidae, which we agree with, since both groups of genera ( Asymptoceras, Aipoceras, Librovitschiceras, on the one hand, and Solenochilus, Acanthonautilus, on the other) are very different. There is no doubt that the former are closer to the ancestral forms, most likely Rutoceratidae, and the latter are descended from the former.”</p><p>This is similar to what was given by Furnish &amp; Glenister (in Kummel 1964) before: “Conch rapidly expanding, cyrtoconic to coiled, whorls rounded to flattened or possibly impressed dorsally; shell surface smooth to ribbed; modified mature aperture known in most forms; sutures nearly straight; siphuncle marginal and ventral; septal necks orthochoanitic on ventral surface and orthochoanitic to cyrtochoanitic on dorsal side.”</p><p>The two families are characterised as follows:</p><p>Aipoceratidae Hyatt, 1884 . – Ancestral forms with a gyroconic conch; whorl profile usually laterally compressed (Fig. 38).</p><p>Solenochilidae Hyatt, 1893 . – Derived forms with a subinvolute or involute conch; whorl profile circular or depressed (Fig. 39).</p></div>	https://treatment.plazi.org/id/03BF2F39FFDC65707020BD0E8CE0FC77	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFDD65707049BB568940F862.text	03BF2F39FFDD65707049BB568940F862.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Aipoceratidae Hyatt 1884	<div><p>Family Aipoceratidae Hyatt, 1884</p><p>Fig. 38</p><p>Diagnosis</p><p>Family of the superfamily Aipoceratoidea with a gyroconic conch. Whorl profile usually laterally compressed.</p><p>Included genera</p><p>Asymptoceras Ryckholt, 1852 (Tournaisian to Serpukhovian; 6 species).</p><p>Aipoceras Hyatt, 1884 (Tournaisian to Viséan; 7 species).</p><p>Oncodoceras Hyatt, 1893 (Tournaisian; 3 species).</p><p>Librovitschiceras Shimansky, 1957 (Moscovian; 1 species).</p><p>Barskoceras Leonova &amp; Shchedukhin, 2020 (Asselian or Sakmarian; 1 species).</p><p>Remarks</p><p>Of the genera of the family Aipoceratidae, only the two genera Aipoceras and Asymptoceras can be considered well known (e.g., Foord 1900; Miller &amp; Furnish 1939). They show a continuous evolution in the degree of coiling, ending in the genera Acanthonautilus Foord, 1896 and Solenochilus Meek &amp; Worthen, 1870 . At the same time there is a continuous evolution towards a more depressed whorl profile.</p><p>Librovitschiceras appears as a foreign item in the list of genera; this is due to the very different conch morphology with a wide umbilicus and low coiling rate (Fig. 38). The genus has been placed in the family Aipoceratidae because of the marginal ventral position of the siphuncle (Shimansky 1957, 1962, 1967, 1979; Kummel 1964), while Dzik (1984: 173) placed the genus in the Tainoceratidae with question mark. Kummel (1964) did not accept the validity of Librovitschiceras and synonymised the genus with Knightoceras, while Furnish &amp; Glenister (in Kummel 1964, in the same Treatise volume) listed it among the superfamily Aipocerataceae . This controversy cannot be resolved at present.</p></div>	https://treatment.plazi.org/id/03BF2F39FFDD65707049BB568940F862	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFDE6572704CBAAE89D3F951.text	03BF2F39FFDE6572704CBAAE89D3F951.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Solenochilidae Hyatt 1893	<div><p>Family Solenochilidae Hyatt, 1893</p><p>Fig. 39</p><p>Diagnosis</p><p>Family of the superfamily Aipoceratoidea with a subinvolute or involute conch. Whorl profile circular or depressed. Umbilical wall with long, spine-alike outgrows in the adult stage.</p><p>Included genera</p><p>Solenochilus Meek &amp; Worthen, 1870 (Tournaisian to hanghsingian; 35 species).</p><p>Solenocheilus Hyatt, 1884 [synonym of Solenochilus].</p><p>Acanthonautilus Foord, 1896 (Tournaisian; 1 species).</p><p>Remarks</p><p>The family Solenochilidae contains only two genera, Solenochilus and Acanthonautilus, which, according to Kummel (1964: K441), differ only in the shape of the septal necks. As this character has not been studied in most species, little can be said about the clear delimitation of the two genera. It is therefore uncertain whether the very asymmetric distribution of the species described so far, one from Acanthonautilus and about 35 from Solenochilus, will be confirmed in the necessary revision. Mikesh &amp; Glenister (1966) considered it possible that many of the Early Carboniferous species of the family might be better assigned to Acanthonautilus . However, they also admitted that a detailed study of the species, some of which are poorly known, would be necessary for a definitive clarification.</p><p>The species of these two genera are characterised by a peculiar conch morphology, the combination of which is not known in any other group of cephalopods. On the one hand, the conch grows very rapidly in width and height, with a circular or depressed oval whorl profile, and on the other hand, the formation of very conspicuous, long outgrowths on the umbilical wall (Fig. 39).</p><p>Interestingly, very similar umbilical processes also occur in the family Permonautilidae, a genus of the superfamily Liroceratoidea, which is not closely related to Solenochilus . Permonautilus also has a stout conch like Solenochilus, but usually differs from Solenochilus in having a much lower coiling rate (WER ~ 2.60) than Solenochilus (WER ~ 2.80–5.50). The most important difference is the position of the siphuncle, which is almost central in Permonautilus and slightly ventral in Solenochilus .</p></div>	https://treatment.plazi.org/id/03BF2F39FFDE6572704CBAAE89D3F951	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFDF657473A7B878887EFD6B.text	03BF2F39FFDF657473A7B878887EFD6B.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Scyphoceratoidea Ruzhencev & Shimansky 1954	<div><p>Superfamily Scyphoceratoidea Ruzhencev &amp; Shimansky, 1954</p><p>Fig. 40</p><p>Diagnosis</p><p>Superfamily of the suborder Solenochilina, in which the conch is cyrtoconic and rapidly increasing in width and height, with a round or somewhat angular whorl profile. Body chamber large, phragmocone chambers small. Sculpture of transverse ribs or missing. Siphuncle adjacent to the ventral side or close to it. Suture line straight or with small lobes (after Shimansky 1967).</p><p>Included families</p><p>Scyphoceratidae Ruzhencev &amp; Shimansky, 1954 (Early Carboniferous to Early Permian; 6 genera, 14 species).</p><p>Dentoceratidae Ruzhencev &amp; Shimansky, 1954 (Late Carboniferous to Early Permian; 1 genus, 5 species).</p><p>Neptunoceratidae Shimansky, 1957 (Late Carboniferous; 2 genera, 4 species).</p><p>Remarks</p><p>The superfamily Scyphoceratoidea is so far only very poorly known because its representatives are generally very rare and have only been discovered in a few localities. In addition, the individual occurrences are of isolated stratigraphic age and are therefore difficult to integrate into a phylogenetic scenario. It is not even clear whether the genera grouped together in the superfamily actually form a monophyletic unit.</p><p>In the “ Osnovy ”, Shimansky (1962: 117) placed the family Neptunoceratidae in the superfamily Rutocerataceae, while he included the families Scyphoceratidae and Dentoceratidae in the superfamily Aipocerataceae, both belonging to the suborder Rutoceratina . Later (Shimansky 1967, 1979) he combined the three families into the superfamily Rutocerataceae .</p><p>Meanwhile, Flower (1963) discussed these problems in detail and outlined the various possible origins of the scyphoceratids and related cephalopods. However, he did not present a clear phylogenetic scenario.</p><p>Kummel (1964: K442) merged the Dentoceratidae with the Scyphoceratidae and placed them in the superfamily Aipocerataceae . Teichert (1964a: K484) included the family Neptunoceratidae among the “doubtful taxa”. This was mainly due to the discussion by Furnish et al. (1962), who suggested that the specimens of Tetrapleuroceras and Neptunoceras were merely growth stages of Brachycycloceras Miller, Dunbar &amp; Condra, 1933 and therefore belonged to their family Brachycycloceratidae (Furnish et al. 1962) . This hypothesis was also taken up by Dzik (1984: 130), who considered not only the Neptunoceratidae but also the Scyphoceratidae to be synonymous with the Cycloceratidae Hyatt in Zittel, 1900. He only accepted the two genera Neptunoceras and Scyphoceras as valid.</p><p>Niko &amp; Mapes (2011) discussed the systematic position of the Neptunoceratidae; they concluded that the family does not fit into either the order Nautilida or the family Cycloceratidae due to its combination of characters. They therefore rejected the classification schemes advocated by Shimansky (1967) and Dzik (1984) and left the systematic classification in uncertainty. King &amp; Evans (2019: 71) discussed the similarity of Brachycycloceras and Texanoceras Niko &amp; Mapes, 2011 and suggested that both genera may be better assigned to the Nautilida .</p><p>Due to the lack of new material, the problems identified cannot be resolved at present. Therefore, the families (Fig. 40) in question are tentatively placed in the Aipoceratoidea without further discussion.</p></div>	https://treatment.plazi.org/id/03BF2F39FFDF657473A7B878887EFD6B	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFD965747011BC418E73FB10.text	03BF2F39FFD965747011BC418E73FB10.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Neptunoceratidae Shimansky 1957	<div><p>Family Neptunoceratidae Shimansky, 1957</p><p>Diagnosis</p><p>Family of the superfamily Scyphoceratoidea with a slightly cyrtoconic conch. Whorl profile subtriangular. Sculpture with transverse ribs. Siphuncle between the centre and the convex side (after Shimansky 1962).</p><p>Included genera</p><p>Tetrapleuroceras Shimansky, 1949 (Gzhelian; 3 species).</p><p>Neptunoceras Shimansky, 1949 [synonym of Tetrapleuroceras Shimansky, 1949].</p><p>Texanoceras Niko &amp; Mapes, 2011 (Gzhelian; 1 species).</p></div>	https://treatment.plazi.org/id/03BF2F39FFD965747011BC418E73FB10	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFD9657473CCBBBC8907F97B.text	03BF2F39FFD9657473CCBBBC8907F97B.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Scyphoceratidae Ruzhencev & Shimansky 1954	<div><p>Family Scyphoceratidae Ruzhencev &amp; Shimansky, 1954</p><p>Diagnosis</p><p>Family of the superfamily Scyphoceratoidea with a cyrtoconic conch with large body chamber and small phragmocone. Whorl profile oval. Without sculpture or with transverse ribs. Siphuncle at the convex side (after Shimansky 1967).</p><p>Included genera</p><p>Scyphoceras Ruzhencev &amp; Shimansky, 1954 (Serpukhovian to Artinskian; 6 species).</p><p>Mariceras Ruzhencev &amp; Shimansky, 1954 (Kungurian; 3 species).</p><p>Venatoroceras Ruzhencev &amp; Shimansky, 1954 (Artinskian; 1 species).</p><p>Sorinoceras Flower, 1963 (Kungurian; 1 species).</p><p>Cherokeeoceras Windle, 1973 [nomen nudum; Carboniferous; 2 species].</p><p>Arcuatoceras Niko, Mapes &amp; Yacobucci, 2009 (Serpukhovian; 1 species).</p></div>	https://treatment.plazi.org/id/03BF2F39FFD9657473CCBBBC8907F97B	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
03BF2F39FFD965777020B851895FFED9.text	03BF2F39FFD965777020B851895FFED9.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Dentoceratidae Shimansky 1957	<div><p>Family Dentoceratidae Shimansky, 1957</p><p>Diagnosis</p><p>Family of the superfamily Scyphoceratoidea with a conical, almost straight conch. Whorl profile rounded (after Shimansky 1962).</p><p>Included genus</p><p>Dentoceras Ruzhencev &amp; Shimansky, 1954 (Bashkirian to Artinskian; 5 species).</p></div>	https://treatment.plazi.org/id/03BF2F39FFD965777020B851895FFED9	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Korn, Dieter	Korn, Dieter (2025): A revised classification of the Carboniferous and Permian Nautilida. European Journal of Taxonomy 1017: 1-85, DOI: 10.5852/ejt.2025.1017.3065, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3065/13693
