taxonID	type	description	language	source
03ECD041AA28FF953C97FB18138D361F.taxon	diagnosis	DIAGNOSIS. — Paired premaxillae not sutured in midline, maxilla does not extend posterior to midorbital level. Small rostral, paired lateral postrostrals followed by a large median second postrostral. Supraoccipital prominent in skull roof. Two to three rows of paired bones, including supraorbitals, over orbits. Three bones in anteroposterior otic series. Infraorbital series of six to ten bones lacking a specialized posterodorsal infraorbital or “ postorbital ”. Suborbitals numerous, variable, extending under orbit. Narrow dorsal and ventral preoperculars. Interopercular rays or interopercular bones present, that may carry a branch of the preopercular lateral line canal. Single large opercular bone ventral to two to for smaller postspiraculars; branchiostegal rays few, not extending forward under mandible. Braincase ossified as several bones; parasphenoid extends entire length of braincase. Presupracleithrum large. Body laterally compressed, discoidal; squamation complete, deepened peg-andsocket scales on anterior flank. Caudal hemiheterocercal; fin rays well spaced.	en	Lund, Richard (2000): The new Actinopterygian order Guildayichthyiformes from the Lower Carboniferous of Montana (USA). Geodiversitas 22 (2): 171-206, DOI: 10.5281/zenodo.4664626
03ECD041AA28FF953ECDFE5414363565.taxon	materials_examined	TYPE GENUS. — Guildayichthys n. gen. by original designation.	en	Lund, Richard (2000): The new Actinopterygian order Guildayichthyiformes from the Lower Carboniferous of Montana (USA). Geodiversitas 22 (2): 171-206, DOI: 10.5281/zenodo.4664626
03ECD041AA28FF953ECDFE5414363565.taxon	diagnosis	DIAGNOSIS. — As for order, only family.	en	Lund, Richard (2000): The new Actinopterygian order Guildayichthyiformes from the Lower Carboniferous of Montana (USA). Geodiversitas 22 (2): 171-206, DOI: 10.5281/zenodo.4664626
03ECD041AA28FF953F35FD9813E43303.taxon	materials_examined	TYPE SPECIES. — Guildayichthys carnegiei n. gen. n. sp. ETYMOLOGY. — Named after John Guilday, late Curator of Fossil Mammals of Carnegie Museum, Pittsburgh, for his unique appreciation of the beauty of life.	en	Lund, Richard (2000): The new Actinopterygian order Guildayichthyiformes from the Lower Carboniferous of Montana (USA). Geodiversitas 22 (2): 171-206, DOI: 10.5281/zenodo.4664626
03ECD041AA28FF953F35FD9813E43303.taxon	diagnosis	DIAGNOSIS. — Teeth short, and absent posterior to mid-maxillary and mid-dentary level. Posterior end of maxillary extending to midorbital level. Parietals meet in dorsal midline. Three rows paired bones over orbits. Five to six interopercular rays extending posterior to quadrate. Seven to eight branchiostegals, two dorsally concave, one expanded posteriorly and four to five ventrally concave, plus two lateral gulars. Dorsal ridge scales from occiput to dorsal fin bear posteriorly projecting spines; imperceptible transition from dorsal ridge scales to dorsal fin rays. Rays of leading edges of dorsal and anal fins closely spaced, following rays of other fins well spaced; all fin rays jointed and unbranched. Anal fin with two to three short leading spines, caudal fin slightly forked.	en	Lund, Richard (2000): The new Actinopterygian order Guildayichthyiformes from the Lower Carboniferous of Montana (USA). Geodiversitas 22 (2): 171-206, DOI: 10.5281/zenodo.4664626
03ECD041AA28FF9E3EC7FB7F10A9367B.taxon	materials_examined	HOLOTYPE. — CM 41071. REFERRED SPECIMENS. — MV 6045, 6046, 6932, 7671, 7758, 7795. CM 27293, 27297, 35217, 37548, 37549 - 37550, 41010, 46091, 46095, 46131, 46293, 46294, 46295, 46296, 46297. ROM 36560, 41039, 41042, 41047, 43012. FMNH PF 10026.	en	Lund, Richard (2000): The new Actinopterygian order Guildayichthyiformes from the Lower Carboniferous of Montana (USA). Geodiversitas 22 (2): 171-206, DOI: 10.5281/zenodo.4664626
03ECD041AA28FF9E3EC7FB7F10A9367B.taxon	etymology	ETYMOLOGY. — Named in honor of Andrew Carnegie, founder of Carnegie Museum of Natural History, Pittsburgh, Pennsylvania. HORIZON AND LOCALITY. — Bear Gulch Limestone lens, Bear Gulch Limestone member of the Heath Formation, Big Snowy Group, south of Becket, Fergus County, Montana.	en	Lund, Richard (2000): The new Actinopterygian order Guildayichthyiformes from the Lower Carboniferous of Montana (USA). Geodiversitas 22 (2): 171-206, DOI: 10.5281/zenodo.4664626
03ECD041AA28FF9E3EC7FB7F10A9367B.taxon	diagnosis	DIAGNOSIS. — For meristics see Table 1. Diagnosis as for genus, only species.	en	Lund, Richard (2000): The new Actinopterygian order Guildayichthyiformes from the Lower Carboniferous of Montana (USA). Geodiversitas 22 (2): 171-206, DOI: 10.5281/zenodo.4664626
03ECD041AA28FF9E3EC7FB7F10A9367B.taxon	discussion	REMARKS All skull bones have ganoine sculpturing of long ridges; either the mesial or the anterior face of each ridge lies at a low angle to the plane of the bone while the opposite face meets the bone approximately perpendicularly. Ganoine ridges on the gulars are of the reverse orientation (Fig. 2). Scales of the anterior trunk have pegand-socket joints and have ganoine sculpturing of faint marginal vertical lines; all trunk scales are pectinated and the deepened ventral abdominal scales are particularly strongly pectinated. Only the central flank scale rows are markedly deepened (rows 2 - 5 below the lateral line). The anteri- or scales of these rows average 3.85 times deeper than wide. Squamation at the bases of dorsal and anal fins is of small thin scales, extending as lobes over and under the caudal peduncle. The statistics of Guildayichthys (Tables 1; 2) are based upon an inadequate sample size and may be misleading. Standard length-maximum height correlation is strong, and caudal peduncle proportions also correlate. No other recorded parameters show meaningful correlations.	en	Lund, Richard (2000): The new Actinopterygian order Guildayichthyiformes from the Lower Carboniferous of Montana (USA). Geodiversitas 22 (2): 171-206, DOI: 10.5281/zenodo.4664626
03ECD041AA28FF9E3EC7FB7F10A9367B.taxon	description	DESCRIPTION Lateral aspect of skull (Figs 2 - 4) The paired premaxillae (P, Figs 3; 4) are high, narrow and separated posteriorly in the midline where they meet the rostral. They are firmly attached only to the first infraorbital posteriorly. Short styliform to conical teeth are borne in a narrow band along the oral margin. The maxilla is elongate and narrow (height one seventh of length), extends to midorbital level and overlaps the posterodorsal rim of the mandible. Short teeth are borne only upon the anterior half of the maxilla. There are five to six bones in the infraorbital lateral line canal series (IO, Figs 3; 4). The most anterior is narrow and forms the ventral edge of the posterior nostril. The second is large and moderately expanded anteriorly. The remaining elements are quite narrow, the most posterodorsal of which is tightly associated posteriorly with a thin and large bone. The latter two bones cover the dilator opercular fossa and articulate with the skull roof. A series of thin suborbitals extend from the skull roof to midorbital level. There is a short dorsal and a taller ventral preoperculum, both anteroposteriorly narrow, carrying the preopercular canal from the margin of the skull roof to the posterior end of the lower jaw (POPD, POPV, Figs 3; 4). Two small postspirac- ular bones (see Polypterus, Pehrson 1958) lie dorsal to the tall, narrow, principal bone of the opercular series. The opercular is flanked ventrally by a series of branchiostegals, two dorsally concave, the next a posteriorly widened triangle, followed by 4 - 5 ventrally concave, deeply overlapping bones and a ventral plate (posterolateral gular). The plate is divided anteroposteriorly in one specimen (Fig. 3); a narrow lateral gular lies anterior to the plate and mesial to the mandible. A series of five mobile, overlapping interopercular rays (Fig. 2; I, Fig. 3) extends from the posterior margin of the mandible to the anteroventral edge of the opercular. There is strong evidence in MV 6045 of either lateral line pores or pit-organs in the two rays closest to the mandible. The lateral surface of the mandible consists of a large dentary and smaller, posterior, angular. No surangular is visible. Short conical teeth occupy the anterior half of the oral margin of the dentary. The mandibular lateral line canal traverses the mandible near its ventral margin, and bends abruptly dorsad in the angular. The articular facet is located slightly below a projection of the dorsal margin of the jaw that presumably functioned as a coronoid process. Skull roof (Figs 3; 4; 14 A; 15 C) The small median rostral (R, Figs 3; 4) is followed by a paired postrostral that is notched for the mesial margin of the dorsal nostril. An ethmoid commissure has not been observed. A moderately large median second postrostral extends past the level of the anterior edge of the parietals. The supratemporal commissure crosses the midline anterior to the posterior margin of the supraoccipital (Figs 3; 14 A). The posterior border of the anterior (dorsal) nasal opening is formed by the most anterior of a series of two to three narrow bones. This series extends lateral to the postrostrals, and mesial to the nasal and supraorbital, and abuts posteriorly against the frontal, the intertemporal, or both (Figs 3; 4). A thin nasal bone bridges the space between nostrils. The course, or even the presence of the supraorbital canal in the nasal region is uncertain; the canal can only be followed in the frontal and parietal and may lie under the suture between the pre-frontal and the more lateral series. The supraorbital canal in MV 6045 bears a short posteromesial branch in the frontal before continuing on to the parietal; the canal does not reach the transverse pit line. There are three bones in the otic canal series, the largest and most anterior, the intertemporal (IT, Figs 3; 4), receiving the infraorbital canal from the posterodorsal infraorbital. Pores associated with a profundus branch of the otic canal (Poplin 1973) extend forward within the intertemporal from the junction with the infraorbital canal in MV 6045 (Fig. 3). Two to three pores in a transverse row extend mesially across the supratemporal and parietal toward the transverse pitline but there is no evidence for an underlying canal branch. The posterior margin of the skull roof in MV 6045 is bordered by one pair of bones bearing the canal intersection characteristic of the extrascapular. In CM 41010, however, two pairs of bones are evident in the same space, posttemporal and extrascapular (Fig. 4). In neither condition do these bones extend to the dorsal midline. The braincase and the floor of the olfactory cup are well ossified. Details, however, are obscured by overlying bones. A short process, possibly a palatobasal (basal) process, is visible in the orbital region of CM 41010. Neither palate nor visceral skeleton is visible. Postcranial Shoulder Girdle. The posttemporal is abutted anteroventrally by a presupracleithrum (Lund & Melton 1982) and posteroventrally by a large supracleithrum. The supracleithrum-cleithrum contact is masked by the operculum; a tall, thin postcleithrum is present and may have served to strengthen what appears to be a very limited area of contact. The cleithrum is deeply notched for the insertion of the pectoral fin. The scapulocoracoid is ossified in a thin sheet and supports one radial for each pectoral fin ray. Clavicles are absent. Scales have strong peg-and-socket articulations, smooth ganoine coatings, and are slightly pectina- ted. Anterior flank and abdominal scales are moderated deepened. There is an abrupt caudal inversion, and the scaled body axis continues past the last caudal fin ray. A complete series of median dorsal scutes extends from the head to the origin of the dorsal fin; as the series approaches the dorsal fin, the scutes increase in height and the sharp posteriorly directed spine of each overlaps the spine of the following scute. The bases of the first jointed fin rays originate behind the last of the dorsal scutes and level with the bases of the scutes. There are two to three dorsal scutes between the end of the dorsal fin and the caudal lobe, followed by a series of dorsal caudal scutes that extend to the end of the caudal axis. There is a series of short, stout, strongly serrated abdominal scutes that extend from the shoulder girdle to the pelvic fins. All fins are composed of well-spaced and jointed rays. The pectoral, dorsal and anal fins are supported on finely scaled lobes. The pelvic fin is moderate in length, and the caudal fin is slightly forked and slightly inequilobate. There are no fin fulcrae. No postcranial endoskeletal detail is available.	en	Lund, Richard (2000): The new Actinopterygian order Guildayichthyiformes from the Lower Carboniferous of Montana (USA). Geodiversitas 22 (2): 171-206, DOI: 10.5281/zenodo.4664626
03ECD041AA23FF9E3CDEFEF6121D344A.taxon	materials_examined	TYPE SPECIES. — Discoserra pectinodon n. gen. n. sp. by original designation.	en	Lund, Richard (2000): The new Actinopterygian order Guildayichthyiformes from the Lower Carboniferous of Montana (USA). Geodiversitas 22 (2): 171-206, DOI: 10.5281/zenodo.4664626
03ECD041AA23FF9E3CDEFEF6121D344A.taxon	etymology	ETYMOLOGY. — Discoserra, serrated disc, descriptive of the appearance of the body in lateral view.	en	Lund, Richard (2000): The new Actinopterygian order Guildayichthyiformes from the Lower Carboniferous of Montana (USA). Geodiversitas 22 (2): 171-206, DOI: 10.5281/zenodo.4664626
03ECD041AA23FF9E3CDEFEF6121D344A.taxon	diagnosis	DIAGNOSIS. — Teeth of the premaxilla, maxilla and dentary long, thin, and styliform. Posterior end of maxilla does not extend back to level of anterior margin of orbit. Parietals excluded from contact in dorsal midline by postrostral 2, which contacts supraoccipital. No transverse supratemporal commissure in supraoccipital. Two rows of paired bones over orbit. One to three interopercular bones; two to three small postspiraculars and a presupracleithrum. Branchiostegals very variable in size, number and shape. Dorsal ridge scales with small, forwardly facing hooks; two to three small anal fin hooks. Origin of anterior edge of dorsal fin set well below dorsal margin of ridge scales. All fins with well spaced rays; pelvic fin reduced, caudal fin rounded.	en	Lund, Richard (2000): The new Actinopterygian order Guildayichthyiformes from the Lower Carboniferous of Montana (USA). Geodiversitas 22 (2): 171-206, DOI: 10.5281/zenodo.4664626
03ECD041AA23FF983C9AFCBA10F031DB.taxon	materials_examined	HOLOTYPE. — CM 30621. REFERRED SPECIMENS. — MV 2772, 2773, 2956, 2984, 3579, 3810, 3811, 7669, 7670, 7756, 7757, 7793, 7794. CM 27290 - 27292, 27294 - 27296, 27298, 27333, 35206 - 35216, 35409, 35547, 37545 - 37547, 37665, 41009, 44500, 46201 - 46206, 48650, 48651, 48717 - 48720, 48841, 62794 - 62802. ROM 36562, 41030, 41169, 43003, 43115, 43976.	en	Lund, Richard (2000): The new Actinopterygian order Guildayichthyiformes from the Lower Carboniferous of Montana (USA). Geodiversitas 22 (2): 171-206, DOI: 10.5281/zenodo.4664626
03ECD041AA23FF983C9AFCBA10F031DB.taxon	etymology	ETYMOLOGY. — Pectinodon, in reference to the long teeth.	en	Lund, Richard (2000): The new Actinopterygian order Guildayichthyiformes from the Lower Carboniferous of Montana (USA). Geodiversitas 22 (2): 171-206, DOI: 10.5281/zenodo.4664626
03ECD041AA23FF983C9AFCBA10F031DB.taxon	diagnosis	DIAGNOSIS. — For meristics see Table 1. Other characters as for genus, only species.	en	Lund, Richard (2000): The new Actinopterygian order Guildayichthyiformes from the Lower Carboniferous of Montana (USA). Geodiversitas 22 (2): 171-206, DOI: 10.5281/zenodo.4664626
03ECD041AA23FF983C9AFCBA10F031DB.taxon	discussion	REMARKS The statistics of Discoserra (Table 3) are remarkable. The number of dorsal fin rays correlates with the numbers of anal and caudal rays as well as those of the precaudal ridge scales. The number of caudal rays also correlates with the number of lateral line scales and a size parameter, maximum height. Pelvic position in scale rows along the lateral line negatively correlates with number of lateral line scales. Scale rows above the lateral line correlates with size parameters, while scale rows below the lateral line do not. Maximum height correlates well with most morphometrics, and excellently with caudal peduncle width. Caudal peduncle length correlates only with caudal angle. Despite these correlations, Discoserra pectinodon is morphologically and statistically the most variable fish in the Bear Gulch fauna. It has not proven possible to consistently isolate variant morphologies that would suggest separate populations either through space or time; in fact several bone complexes such as branchiostegals and suborbitals are not bilaterally consistent within all individuals.	en	Lund, Richard (2000): The new Actinopterygian order Guildayichthyiformes from the Lower Carboniferous of Montana (USA). Geodiversitas 22 (2): 171-206, DOI: 10.5281/zenodo.4664626
03ECD041AA23FF983C9AFCBA10F031DB.taxon	description	DESCRIPTION Ganoine Skull bones have ganoine sculpturing of coarse, irregular longitudinal to circumferential convex ridges. The central areas of broad bones such as the opercular may bear ganoine sculpturing that grades from tubercles centrally to ridges peripherally (Fig. 6). Scales Lateral flank scales are up to 3.6 times deeper than wide and bear strong peg-and-socket joints as well as internal anterior thickenings. Most lateral scale rows are deepened. Ganoine sculpturing varies on the flank scales from few, relatively coarse circumferential grooves near the dorsum to finer circumferential striations at midflank. The stout, deep ventral abdominal scales are strongly serrated in addition to bearing coarse circumferential grooves. Squamation at the bases of dorsal and anal fins is of small, thin scales, extended into lobes that project over and under the caudal peduncle. A significant bulk of dorsal and anal fin radial musculature is indicated. Lateral aspect of skull (Figs 7; 8) The premaxillae (P, Figs 7; 8) are about five times longer than wide, and are not firmly sutured either across the midline or to any other bones. There appears to have been a tendency for them to fuse, in some individuals, to the anteriormost infraorbital posteriorly. The premaxillae bear a single row of long, fine, styliform, closely set teeth. The maxilla (M, Figs 7; 8) is most often triangular in shape, varying from 1: 4 to 1: 5 in length: height ratio. It is not firmly held to any other skull bones. A mesial view of the maxilla of one specimen is available, that shows what appears to be a slight anterior articular facet (CM 27290). The single row of long, closely fit teeth diminishes abruptly in height and ends at one third of the distance to the posterior end of the bone. The infraorbital lateral line canal bones are very variable in number (I 0, Figs 7 - 9). The first infraorbital is short and in close contact with the premaxilla. The second element is wedge shaped, of variable length, and may either be absent or fused to the large third anterior infraorbital in some specimens. When present, it forms the anteroventral margin of the posterior nostril. The third anterior infraorbital is large and trapezoidal, with pores distributed irregularly and remote from the course of the infraorbital canal. As many as five to seven additional infraorbitals, most only surrounding the infraorbital canal, rim the orbit. Pores from the infraorbital bones below the orbit are irregularly distributed upon the suborbital bones ventrally. The most posterodorsal infraorbital is firmly associated with a large, thin bone that covers the dilator opercular fossa. Suborbitals (Figs 7; 8) on the posterodorsal cheek are scale-like. Under the orbit, the suborbital bones vary in number and shape from one long element (CM 35215) to a series of seven (CM 27292). Normally, a trapezoidal element or elements lie dorsal to the articular region of the mandible, followed by a variable number of small posterodorsal bones; in several specimens an anterior triangular element intervenes between the third infraorbital and the trapezoidal bone or bones (CM 27294, 35206, 35211). The dorsal of the two preopercular bones contacts the skull roof; it is shorter and thinner than the ventral element. The preopercular canal branches into an anteroventral and a ventral branch near the mandibular end of the bone (Fig. 8). There is one tall, narrow principal opercular bone, ventral to two to four considerably smaller bones and a large presupracleithrum (PSP, Figs 7; 8). The branchiostegals are very variable and are not always bilaterally symmetrical. A typical pattern is one dorsally concave ray below the opercular, followed ventrally by one that widens posteriorly, four to six ventrally concave rays and a single ventral plate (posterolateral gular). Variations are detailed in Figure 10. One to three small interopercular bones (I, Figs 7; 8) are found between the posterior end of the mandible, the posteroventral end of the ventral preopercular and the anteroventral end of the opercular. There is clear evidence for a branch of the mandibular lateral line canal extending under the anterior of these bones, and some indication that the ventral branch of the preopercular lateral line canal extended ventrally between the interoperculars. This is best displayed in CM 35206. The external aspect of the lower jaw consists of a large dentary and a small angular, with a single row of long, slim teeth along the anterior oral margin of the dentary. A surangular seems to be absent. The internal aspect of the mandible consists of two elements, an extensive prearticular that seems to lack teeth, and an articular with a strongly elevated anterior wall and a dorsomesial pit for adductor musculature insertion (CM 27290). The mandibular lateral line canal lies near the ventral border of the dentary; the canal is L-shaped in the angular but a posterior continuation of the canal is evident in several specimens. Skull roof (Figs 7; 8; 14 B) The long, narrow median rostral (R, Figs 7; 8) extends back to the level of the anterior border of the nostrils. While lateral line canals enter the median rostral from either side, a complete ethmoid commissure has not been seen. The paired postrostrals extend along the dorsal midline between the nostrils, receiving the posteromedian end of the median rostral between them. The posterior median postrostral contacts the supraoccipital posteriorly and excludes the frontal and parietal bones from the dorsal midline (Fig. 14 B). The supraoccipital is a significant bone of both the braincase, the skull roof, and the posterior cranial surface, where it bears a strong posteriorly projecting crest. The supratemporal commissure does not enter the supraoccipital. The more anterior of two pre-frontal bones (PF, Figs 7; 8) forms the posterior border of the anterior nostril, and a small nasal bone (N, Figs 7; 8) extends between the anterior and posterior nasal openings. The posterior prefrontal is narrow and flanked laterally by a single supraorbital bone. The supraorbital lateral line canal extends from the posterior pre-frontal through the frontal and parietal; the canal cannot be traced anterior to the posterior pre-frontal. The parietal bears a short transverse pitline, which may be continued laterally onto the supratemporal, the second of the three bones of the otic series, in the form of a few pores or pits. Behind the skull roof the supratemporal canal intersects with the extrascapular canal in a bone lateral to two paired extrascapulars, but there is no evidence for a complete commissure. Visceral skeleton The palate and suspensorium are displayed only in CM 27290 (Fig. 11). No palatal teeth can be seen. The hyomandibula (H, Fig. 11) has a ventral process one half of the total height of the bone and has a prominent central foramen for the hyomandibular branch of nerve VII. The metapterygoid (ME, Fig. 11) is attached only to the anterior edge of the ventral process of the hyomandibula, leaving ample room for a large spiracle. There is an indication of a symplectic and a palatal groove for this bone near the posterior edge of the quadrate. The quadrate condyle is poorly preserved but faced forward; a prominent ventral facet posterior to the condyle may have been for attachment of a strong quadrate-mandibular ligament. A stout ceratohyal is visible, with branchiostegal rays attached, in FMNH PF 10207. There are eight to ten sclerotic bones in the eye, the largest of which are the dorsal and anterior bones. Braincase The braincase is well ossified and is devoid of sutures that would delineate individual bones. No occipital fissure is evident, unless the small foramina (OC, Fig. 12) are remnants of such a structure. Structures are best displayed in CM 27295, although CM 27290 and CM 35547 have also contributed information (Figs 11; 12). The parasphenoid (PS, Figs 11; 12) extends the entire length of the braincase. It has small lateral wings, no obvious palatal articulations, and is strongly V-sha- ped in transverse section through most of its length. The ethmoid region is sheathed by two thin ossifications, the dorsal one also forming the floor of the nasal capsule and enclosing a foramen for the olfactory nerve. The sphenoid region is strongly notched for the exit of the optic nerve (II, Fig. 12). The sphenotic ossification area projects laterally beyond the skull roofing bones and is excavated by a deep pit with an apparent narrow foramen in its floor. This pit clearly is of the form and position of the dilator opercular fossa (DO, Fig. 12) of teleosts and seems to shows no relationship to a spiracular canal as reported for some chondrosteans (Patterson 1975). Foramina for branches of cranial nerves V, VII, and X are visible (Fig. 12). A strong posteriorly directed supraoccipital crest projects beyond the posterior face of the braincase. Postcranial Clavicles are absent in the shoulder girdle. The cleithrum is deeply notched for the insertion of the pectoral fin and has a strong peg-and-socket articulation with the supracleithrum. The postcleithrum is small. All scales have strong peg-and-socket articulations, smooth ganoine coatings, and have finely pectinated posterior borders (Fig. 13 C, D). The anterior flank and abdominal scales are tall and narrow. There is no caudal inversion, and the unscaled body axis extends to the last caudal fin ray and bears only long, fine dorsal scutes. A complete series of median dorsal scutes extends from the head to the origin of the dorsal fin; each scute taller than the preceding one and bearing a small forwardly facing hook. The bases of the first jointed fin rays originate behind the last of the dorsal scutes and level with the bases of the scutes. There are two to three dorsal and ventral scutes between the end of the dorsal fin and the caudal lobe. There is a series of tall, thick, strongly serrated abdominal scutes that extend from the shoulder girdle to the pelvic fins, and there are two to three pre-anal scutes. All fins are composed of well-spaced and jointed rays. The pectoral, dorsal and anal fins are supported on finely scaled lobes. The pelvic fin is very small, and the caudal fin is rounded but not dorsoventrally symmetrical. There are no fin fulcrae. Postcranial endoskeleton (Fig. 13) The pectoral fin base is lobed. Up to 11 to 12 radials are visible supporting the pectoral fin rays. The pelvic fin is very small and no endoskeleton is known. The axial skeleton contains 12 to 13 precaudal segments, 13 to 14 caudal segments anterior to the caudal fin endoskeleton and 11 segments are visible in the sharply upturned caudal lobe. Precaudal neural arches are paired, and while there are blocky precaudal ventral arch elements, there are no ossified interarcuals. Caudal neural arches are fused across the midline. Neural spines are not fused to the arches but extend from occiput to the end of the caudal as a complete separate series. Dorsal to the neural spines, a complete supraneural series extends from the occiput to the posterior end of the dorsal fin, the predorsal supraneurals each bearing a dorsal facet for articulation with the dorsal ridge scales (Fig. 13 A, B). Approximately two dorsal fin rays are supported by each supraneural (baseost); axonosts are not evident. Haemal arches are fused across the midline and articulate with separate haemal spines; these in turn support the infrahaemal series. The origin of the anal fin is supported by two haemal and infrahaemal elements. The anal fin ray: infrahaemal ratio is also approximately 2: 1.	en	Lund, Richard (2000): The new Actinopterygian order Guildayichthyiformes from the Lower Carboniferous of Montana (USA). Geodiversitas 22 (2): 171-206, DOI: 10.5281/zenodo.4664626
