identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
03F52665D050FF8FFC609E34FB8C74CD.text	03F52665D050FF8FFC609E34FB8C74CD.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Palaeoproteus miocenicus (Vasilyan and Yanenko 2020)	<div><p>Palaeoproteus cf. miocenicus</p><p>Figures 3–4</p><p>Material. Hambach 6C: three atlases (IPB-HaH 2117, IPB-HaH 2175, IPB-HaH 2164); one trunk vertebra (IPB-HaH 2162). Hambach 11: two dentaries (IPB-HaR 2043, IPB-HaR 2071); one anterior trunk vertebra (IPB-HaR 2183); one trunk vertebra (IPB-HaR 2008). Hambach 11C: five trunk vertebrae (IPB-HaR 2404/2408).</p><p>Description. IPB-HaR 2071 (Figure 3) represents part of the posterior end of a very large dentary. It is very fragmentary. IPB-HaR 2043 is also very large and robust. It represents a portion originally located somewhere in the middle of the dentary. The pars dentalis of the dentary is composed by a very high dental lamina and a very low subdental lamina. On the medial side, nine tooth positions are visible, hosting the poorly-preserved remains of pleurodont, very high, rather narrow and closely spaced teeth provided with thick walls. Ventral to the pars dentalis, there is a robust shelf, which is not strongly developed medially. The preservation of this shelf is rather poor, but a narrow and shallow groove is visible ventrally. The groove moves towards the medial surface near the anterior end of the fragment. The lateral surface is smooth. In lateral/medial view, the ventral margin is somehow concave, suggesting ventral development of the posterior part of the dentary.</p><p>IPB-HaH 2164 is a very small atlas, but the other ones are larger. The length of the largest atlas, IPB-HaH 2175 (Figure 4 F-I), is 6 mm. All atlases miss almost completely the neural arch, preserving only the centrum. Anteriorly, the occipital joints are wide and mediolaterally elongated, with a suboval/subelliptical shape (i.e., slightly dorsoventrally compressed) in anterior view. They are very shallowly concave and do not coalesce in the middle, being separated by a thin and long processus odontoideus. The processus is slightly slenderer in IPB-HaH 2175 than in the other two specimens. It has a flat dorsal surface and an anteroventrally-directed and strip-like articular surface that is not separated into two distinct lateral areas. There is no postodontoideus foramen at the base of the process. The posterior end of the centrum is represented by a posterior cotyle with a notochordal pit in the middle. The cotyle is circular in IPB-HaH 2175 (Figure 4I) and more mediolaterally compressed in IPB-HaH 2117 (Figure 4D). In both specimens, it is larger than the processus odontoideus. This feature cannot be evaluated in IPB-HaH 2164 because the area is damaged. In IPB-HaH 2715, the ventral surface of the centrum shows a concave area with a number of large foramina (Figure 4G). On the other hand, IPB-HaH 2117 bears a very deep fossa in the middle of the centrum, which is flanked by two smaller symmetrical foramina by the sides and by other even smaller foramina posteriorly (Figure 4B). The ventral surface of IPB-HaH 2164 displays a depressed area by each side of the centrum. Foramina also cover the lateral surface of each processus lateralis in all specimens.</p><p>Both IPB-HaR 2008 (Figure 4 O-T) and IPB-HaR 2408 (Figure 4 U-Z) are amphicoelous and large sized (the centrum length reaches 6.5 mm and 9.5 mm, respectively). A notochordal pit is present in the middle of the large and hourglassshaped centrum. The cotyles are circular in both anterior and posterior views. The ventral surface of the centrum bears two high and sharp longitudinal basapophyses, which run parallel along the entire length of the vertebra. Only in IPB-HaR 2408, the basapophyses contact in the middle at about one third of the centrum length (Figure 4V). Between the basapophyses, various central foramina are present. At least three large ones are visible on IPB-HaR 2008 (Figure 4P), surrounded by other smaller ones, whereas only a number of small ones are visible on IPB-HaR 2408 (Figure 4V). The neural arch is robust and dorsally flattened, being better preserved in IPB-HaR 2408. A neurapophysis is present. It is low anteriorly, but rises to a moderate degree posteriorly. A robust spine is present at the posterior end of the arch, strongly projecting posterodorsally beyond the postzygapophyses. The posterior end of the spine is truncated. A wide and deep, U-shaped anterior notch on the neural arch is visible on IPB-HaR 2408 (Figure 4U), allowing the anterior cotyle to be visible in dorsal view. The deepest part of the notch reaches the posterior margin of the prezygapophyses. The zygapophyses are more or less horizontal in both anterior and posterior view. The zygapophyseal facets are suboval. In posterior view, two shallow depressions are visible on the posteroventral surface of the neural arch, flanking a low longitudinal ridge running along the ventral side of the neural spine. The transverse processes are moderately developed and posterolaterally directed. Ventrally, they are connected to the centrum by moderately-(IPB-HaR 2008) or well-developed (IPB-HaR 2408) anterior ventral crests (anterior alar process in Vasilyan and Yanenko, 2020) and little-developed posterior ventral crests. On the other hand, the zygapophyseal crests are not developed. The other vertebrae only preserve isolated centra or fragments of centra, some of them being much smaller than the two previously described (IPB-HaR 2406 is about 4 mm long). Nevertheless, they share the same morphology.</p><p>IPB-HaR 2183 (Figure 4 J-N) is the only trunk vertebra displaying some differences from the other ones. This large vertebra has a very massive, almost 6 mm long centrum, which is amphicoelous, hour-glass-shaped and notochordal. The overall aspect is relatively shorter compared to the trunk vertebra IPB-HaR 2008, coming from the same level. The anterior cotyle is moderately mediolaterally compressed, appearing subelliptical in anterior view. The posterior cotyle, on the other hand, is subcircular in posterior view. The ventral surface of the centrum bears a narrow keel and no basapophyses. A number of small foramina are present by the ventrolateral sides of the centrum, in place of real subcentral foramina. Most of the neural arch is missing, preserving only the right lateral wall and the base of the left one. The transverse processes are long and moderately robust; they are directed posterolaterally. The anterior ventral crest is very low, whereas the posterior one is slightly more developed. Zygapophyseal crests are not developed. The base of the right prezygapophysis is also preserved, but not the zygapophysis itself. The shortness of this vertebra, together with its ventral keel, identify it as an anterior trunk vertebra (Estes et al., 1967).</p><p>Remarks. The diagnostic features recently reported by Vasilyan and Yanenko (2020) allow a rather straightforward identification for these remains as a batrachosauroidid salamander. The dentaries of these urodeles have thick-walled teeth and a ventrally-projecting posterior part. Trunk vertebrae are amphicoelous, with subcircular cotyles, basapophyses, and a posterodorsally-projecting neural spine. The atlases are provided with both anterior and posterior cotyles with a rounded outline, among which the former are large and concave. The well-developed paired ventral basapophyses, as well as maybe the flat neural arch and developed anterior ventral crest, suggest that the batrachosauroidid from Hambach is a member of the European genus Palaeoproteus (Vasilyan and Yanenko, 2020) . In particular, the following combination of features observed in the studied material is diagnostic of P. miocenicus following Vasilyan and Yanenko (2020): overall large size; poorly-developed subdental shelf of dentary; vertebrae with a long neural spine; weakly-concave and slightly dorsoventrally-compressed anterior cotyles of the atlas; external surface of the atlas pierced by foramina of different sizes; strongly pronounced, lip-shaped odontoid process of the atlas (Vasilyan and Yanenko, 2020: p. 8, stated that “In P. miocenicus, the odontoid process is very large in comparison to all known batrachosauroidids”). However, the atlases from Hambach 6C show no postodontoid foramen, in contrast with the type and referred material of P. miocenicus (Vasilyan and Yanenko, 2020) . All four P. miocenicus atlases share the presence of this foramen, whereas it is absent in Palaeoproteus klatti Herre, 1935, and Palaeoproteus gallicus Estes et al., 1967 . Despite this difference, we refrain to name a new species here and attribute the fossils from Hambach 6C to Palaeoproteus cf. miocenicus, due to the overall similarity between bones of P. miocenicus and the German taxon as well as the low sample of atlases that hinders a complete understanding of the real variation of this feature in these animals. Material coming from the youngest level in Hambach also shares the same attribution, given that atlases from this level are currently unknown, and so it is not possible to verify the presence or absence of a postodontoid foramen.</p></div>	https://treatment.plazi.org/id/03F52665D050FF8FFC609E34FB8C74CD	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	Villa, Andrea;Macaluso, Loredana;Mörs, Thomas	Villa, Andrea, Macaluso, Loredana, Mörs, Thomas (2024): Miocene and Pliocene amphibians from Hambach (Germany): New evidence for a late Neogene refuge in northwestern Europe. Palaeontologia Electronica (a 3) 27 (1): 1-56, DOI: 10.26879/1323, URL: http://dx.doi.org/10.26879/1323
03F52665D053FF80FC199AE1FE0E7493.text	03F52665D053FF80FC199AE1FE0E7493.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Palaeoproteus miocenicus (Vasilyan and Yanenko 2020)	<div><p>? Palaeoproteus cf. miocenicus</p><p>Figure 5</p><p>Material. Hambach 6C: one humerus (IPB-HaH 2390).</p><p>Description. This humerus is rather large and robust. It misses only most of the distal epiphysis. The length of the preserved portion is about 16 mm. The bone expands strongly towards the epiphyses. Based on the preserved portion, it appears rather short. The proximal epiphysis is poorly ossified. It has an asymmetrical shape, more expanded toward the ventral side. The posterior surface displays a distinct fossa.</p><p>Remarks. The size of this humerus suggests that it belongs to one of the two largest caudate taxa recognised in Hambach (i.e., either cryptobranchids or batrachosauroidids). The bone appears rather short in general appearance, which hints against Chelotriton, cryptobranchids, and possibly also proteids. Its shortness rather recalls the shortened limbs of P. klatti (see Vasilyan and Yanenko, 2020). Furthermore, the general morphology of the bone differs from the fragment of humerus attributed to Mioproteus gardneri Venczel and Codrea, 2018, whereas the poorly ossified proximal end hints against Chelotriton . Therefore, IPB-HaH 2390 is here attributed with doubt to the batrachosauroidid taxon found in the Hambach assemblage, Palaeoproteus cf. miocenicus .</p></div>	https://treatment.plazi.org/id/03F52665D053FF80FC199AE1FE0E7493	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	Villa, Andrea;Macaluso, Loredana;Mörs, Thomas	Villa, Andrea, Macaluso, Loredana, Mörs, Thomas (2024): Miocene and Pliocene amphibians from Hambach (Germany): New evidence for a late Neogene refuge in northwestern Europe. Palaeontologia Electronica (a 3) 27 (1): 1-56, DOI: 10.26879/1323, URL: http://dx.doi.org/10.26879/1323
03F52665D05CFF80FED19B23FE5F7218.text	03F52665D05CFF80FED19B23FE5F7218.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Euronecturus grogu Macaluso, Villa, and Mors 2022	<div><p>Euronecturus grogu Macaluso, Villa, and Mörs, 2022</p><p>Material. Hambach 6C: five atlases (IPB-HaH 2119/2121, IPB-HaH 2150, IPB-HaH 2165).</p><p>Remarks. These atlases were recently described as types of a new proteid taxon, E. grogu . The reader is referred to Macaluso et al. (2022b) for further information.</p></div>	https://treatment.plazi.org/id/03F52665D05CFF80FED19B23FE5F7218	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	Villa, Andrea;Macaluso, Loredana;Mörs, Thomas	Villa, Andrea, Macaluso, Loredana, Mörs, Thomas (2024): Miocene and Pliocene amphibians from Hambach (Germany): New evidence for a late Neogene refuge in northwestern Europe. Palaeontologia Electronica (a 3) 27 (1): 1-56, DOI: 10.26879/1323, URL: http://dx.doi.org/10.26879/1323
03F52665D05CFF81FED59CB4FDD47309.text	03F52665D05CFF81FED59CB4FDD47309.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Mioproteus wezei Estes 1984	<div><p>Mioproteus cf. wezei</p><p>Figure 6</p><p>Material. Hambach 11: nine trunk vertebrae (IPB-HaR 2000/2007, IPB-HaR 2013). Hambach 11C: six trunk vertebrae (IPB-HaR 2400/2403, IPB-HaR 2427/2428).</p><p>Description. These vertebrae (Figure 6) reach a large size and are robustly ossified. The largest one has a centrum length of about 6.5 mm. They display a range of different degree of preservational statuses, from very fragmentary to well preserved. The centrum is amphicoelous and pierced by a wide notochordal canal. Ventrally, the centrum bears a robust and high keel, which is more or less narrow (from sharp to slightly thicker). By the anterior and posterior ends, the keel expands into triangular and flat ventral surfaces. The keel is flanked by small subcentral foramina, sometimes more than one per side. Posteriorly, poorly-developed basapophyses are present. The neural arch is low, without a significant rising posteriorly, and dorsally flat. A neurapophysis is present, being either rather low or slightly higher. It runs almost entirely along the dorsal surface of the arch. The anterior margin of the arch appears straight in dorsal view, even though it is never completely preserved. It is located roughly at midlength of the prezygapophyses. The posterior margin is rather straight (but very slightly wavy, even though with no median notch) and ends well before the end of the postzygapophyses. By each side of the neurapophysis, the posterior end of the dorsal surface of the neural arch carries a well-developed spine, which projects well beyond the posterior margin, but not beyond the postzygapophyses. The spines are well spaced in dorsal view, not strongly extended anteriorly (they do not reach the level of the transverse processes) and not connected to the neurapophysis medially. The zygapophyses are suboval and almost horizontal. The ventral lamina has a subtrapezoidal shape, originated by very well-developed anterior ventral crests and less-developed posterior ones. The zygapophyseal crests are also well developed, but not as much as the anterior ventral crests. The posterior zygapophyseal crests are distinctly convex dorsally in lateral view. Due to the strong development of both the ventral lamina and the zygapophyseal crests, the vertebrae assume a wide appearance in both ventral and dorsal views. The transverse processes are reduced to a small single structure, which is slender and posterolaterally directed. Individualized para- and diapophyses are not clearly discernible. A more-or-less large foramen is visible anterior to the base of the transverse process.</p><p>Remarks. These vertebrae are referred to Mioproteus because of the following combination of features (Estes and Darevsky, 1977): robust and wellossified aspect; well-spaced posterior spines; wide appearance in dorsal and ventral views (i.e., wide neural arch, wide ventral lamina); presence of basapophyses. Three species of Mioproteus are currently known: Mioproteus caucasicus Estes and Darevsky, 1977, M. gardneri, and M. wezei . The vertebrae from Hambach are concordant in size with both M. caucasicus and M. wezei, whereas they are larger than M. gardneri . Regarding their morphology, they differ from M. gardneri in the more developed zygapophyseal crests, the taller neurapophysis, and the more laterally-trending prezygapophyses (Venczel and Codrea, 2018). Most characters reported to be diagnostic for M. wezei are variable, but at least the consistent absence of a connection between the posterior spines and the neurapophysis seems to be sufficiently reliable (Syromyatnikova et al., 2021). This condition is shown by the Hambach material, whereas M. caucasicus either has posterior spine that connect or not to the neurapophysis medially. Strongly dorsally-convex posterior zygapophyseal crests may also be typical for M. wezei (Młynarski et al., 1984; Bailon, 1995; even though Syromyatnikova et al., 2021, mentioned some variation of this feature in Mioproteus vertebrae). Considering this, we here tentatively attribute the Hambach Mioproteus vertebrae to M. wezei, even though pointing out uncertainty over this identification pending a clarification of the diagnostic features within Neogene Mioproteus .</p></div>	https://treatment.plazi.org/id/03F52665D05CFF81FED59CB4FDD47309	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	Villa, Andrea;Macaluso, Loredana;Mörs, Thomas	Villa, Andrea, Macaluso, Loredana, Mörs, Thomas (2024): Miocene and Pliocene amphibians from Hambach (Germany): New evidence for a late Neogene refuge in northwestern Europe. Palaeontologia Electronica (a 3) 27 (1): 1-56, DOI: 10.26879/1323, URL: http://dx.doi.org/10.26879/1323
03F52665D043FF92FCEB98DBFD3E70B3.text	03F52665D043FF92FCEB98DBFD3E70B3.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Palaeobatrachus eurydices Villa, Rocek, Tschopp, van den Hoek	<div><p>Palaeobatrachus eurydices Villa, Roček, Tschopp, van den Hoek Ostende, and Delfino, 2016</p><p>Figures 16–17</p><p>Material. Hambach 11: one sphenethmoid (IPB-HaR 2021); 11 angulars (IPB-HaR 2110/2113, IPB-HaR 2129/2132, IPB-HaR 2144/2146); one trunk vertebra (IPB-HaR 2030); five humeri (IPB-HaR 2148/2152); five ilia (IPB-HaR 2099/2102, IPB-HaR 2147). Hambach 11C: one maxilla (IPB-HaR 2429); one angular (IPB-HaR 2418); two humeri (IPB-HaR 2419/2420).</p><p>Description. IPB-HaR 2429 (Figure 16 A-C) is a fragment of maxilla, measuring about 5.5 mm in length and preserving only the area of the processus palatinus. The bone is robustly built. On the medial side, part of the tooth row is preserved, even though in bad conditions. Four wide tooth positions are preserved, one of them still hosting the base of a tooth. The tooth positions are separated by knob-like structures. The lamina horizontalis is mostly broken, but it clearly extended medially with a toothless portion. No clear ridge is visible ventrally separating the toothed and toothless portion of the lamina. On its dorsal side, a deep recessus vaginiformis is present. The processus palatinus is represented in this specimen by a low, subtriangular structure with a truncated dorsal tip. In dorsal view, it is shifted medially, thus originating a concavity on the lateral surface of the maxilla. Both the anterior and posterior margins of the process are distinctly irregular, and its lateral surface displays few foramina.</p><p>IPB-HaR 2021 (Figure 16 D-G) is a fragmentary sphenethmoid. It is anteroposteriorly elongated and large-sized. The lateral margins of the bone are rather eroded, but distinctly developed laminae supraorbitalis and trabecula seem not to be present. In dorsal view, a long and U-shaped fenestra frontoparietalis is recognizable, even if the left portion of the bone is lacking. Anteriorly to the fenestra, the dorsal surface of the bone is smooth. The contact surface with the parasphenoid is visible on the ventral surface: it is delimited laterally by two low ridges and widens anteriorly.</p><p>Angulars are robust and large-sized. They have a rather deep sulcus cartilagine Meckeli and an anteroposteriorly elongate, stocky and dorsoventrally compressed processus coronoideus. The dorsal surface of the latter is strongly irregular, with pits and/or ridges, and shows a certain degree of individual variation (Figure 17). A few angulars, such as e.g., IPB-HaR 2111 (Figure 17A) and IPB-HaR 2418, bear a small tubercle on the lateral side, in correspondence with the anterior end of the processus coronoideus. The extremitas spatulata is short and broad.</p><p>IPB-HaR 2030 is a fragmentary trunk vertebra provided with a very dorsoventrally compressed centrum. The latter is procoelous, wide, and shows numerous small pits on the ventral surface.</p><p>Humeri (Figure 16 H-M) are very large-sized and lack a fossa cubitalis ventralis. The eminentia capitata and the epicondyles are distally eroded and were probably partly cartilaginous in the living animal. The epicondylus ulnaris is only slightly larger than the epicondylus radialis. The olecranon scar is depressed, but the articular surface with the olecranon of the radioulna is small and poorly developed. All specimens but IPB-HaR 2420 preserve only the distal epiphysis and the distal part of the diaphysis. IPB-HaR 2420 is more preserved, but the proximal end of the bone is still missing. A hint of a robust crista ventralis is recognizable on the ventral surface of the humeri. This is particularly evident in IPB-HaR 2420, which also express the base of a crista paraventralis. Cristae medialis and lateralis are not developed.</p><p>Ilia (Figure 16 N-Q) show a well-developed and elongated dorsal tubercle, but no dorsal crest. The tubercle bends in lateral direction. The large acetabular fossa has a prominent anteroventral rim. The ventral acetabular expansion is not developed, whereas the dorsal one is moderately developed. A supraacetabular fossa is visible dorsally to the acetabulum. A wide and deep interiliac groove is visible on the medial surface of the body of the bone.</p><p>Remarks. Clear diagnostic features of palaeobatrachid anurans in the above-described material are the following (Wuttke et al., 2012; Roček, 2013; Roček et al., 2021): knob-like structures separating tooth positions in the maxilla; elongated sphenethmoid, provided with frontoparietal fenestra longer than half the total length of the bone and with two parallel ridges delimiting the articulation area for the parasphenoid on the ventral surface; coronoid process of the angular either smooth or bearing muscle scars on dorsal surface; vertebral centrum strongly dorsoventrally compressed and with numerous pits on the ventral surface; humerus devoid of fossa cubitalis ventralis (different from Eocene palaeobatrachids, though) and provided with a comparatively small eminentia capitata that is located on or near the long axis of bone, as well as similar-sized epicondyles; ilium with massive dorsal acetabular expansion; large acetabular fossa extending anteroventrally beyond the margin of the ilial body, thus concealing the ventral expansion; dorsal tubercle protruding only slightly in dorsal direction, but more prominent laterally and bearing muscle scars on the lateral surface; distinct horizontal depression on the inner surface of the iliac shaft. Specific attribution to P. eurydices appears also justified, due to the following combination of features (Villa et al., 2016): the interorbital section of the processus cultriformis of the parasphenoid was narrow, but the process becomes wider towards the anterior (as suggested by the divergent longitudinal ridges on the ventral side of sphenethmoid, which delimit laterally the area of attachment of the parasphenoid); the sphenethmoid lacks articular facets for the nasals; the dorsal surface of the sphenethmoid shows no median ridge; the processus coronoideus of the angular extends parallel to most of the extremitas spatulata; the extremitas spatulata is short and broad; the fossa cubitalis ventralis of humerus is absent. Despite its very fragmentary status, the maxilla IPB-HaR 2429 is also very similar in morphology to maxillae of P. eurydices . In particular, it could be somehow representative of a sort of “intermediate” stage between the supposed juvenile maxilla reported by Villa et al. (2016) and the adult ones. Similar to the purported juvenile specimen, IPB-HaR 2429 has a subtriangular processus palatinus, which gives to the bone a concave lateral appearance in dorsal view due to a slight medial shifting. However, the size of the specimen, as well as the number of teeth in the processus palatinus area and the absence of a ridge separating the toothed and toothless portions of the ventral surface of the lamina horizontalis, seem to be more comparable with the adult holotype maxilla of P. eurydices .</p></div>	https://treatment.plazi.org/id/03F52665D043FF92FCEB98DBFD3E70B3	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	Villa, Andrea;Macaluso, Loredana;Mörs, Thomas	Villa, Andrea, Macaluso, Loredana, Mörs, Thomas (2024): Miocene and Pliocene amphibians from Hambach (Germany): New evidence for a late Neogene refuge in northwestern Europe. Palaeontologia Electronica (a 3) 27 (1): 1-56, DOI: 10.26879/1323, URL: http://dx.doi.org/10.26879/1323
03F52665D04EFF93FEF79EE2FCD174ED.text	03F52665D04EFF93FEF79EE2FCD174ED.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Palaeobatrachidae Cope 1865	<div><p>? Palaeobatrachidae indet.</p><p>Figure 18</p><p>Material. Hambach 6C: one maxilla (IPB-HaH 2279).</p><p>Description. IPB-HaH 2279 is a fragmentary and robust maxilla, lacking the anterior and posterior portions. The lamina horizontalis is robust and moderately developed in medial direction. On the ventral surface of the lamina, a low longitudinal ridge separates a toothless medial half from the crista dentalis. Teeth were pleurodont, but no one is preserved; they were separated by small processes, which are now eroded. Nine tooth positions are recognizable. In the middle of the dorsal surface of the lamina, a deep and circular recess is visible. By the recess, the lateral wall of the maxilla bends medially. The processus palatinus should be located by this bending, but it is not clearly recognizable in this specimen; this could be either due to a real absence of the processus or, more likely, to preservational reasons. The lateral surface of the bone is smooth.</p><p>Remarks. This specimen from Hambach 6C is rather similar to the maxillae of P. eurydices in (Villa et al., 2016): overall robustness; presence of the circular recess (recessus vaginiformis for the processus maxillaris anterior, which is the anterior termination of the subocular bar; Roček, 2003: 1941) on the lamina horizontalis; presence of processes separating the teeth (even though it is not possible to say if they were knob-like in origin). On the ventral surface of the lamina horizontalis, the low ridge delimitating medially the toothed area recalls the maxilla RGM 632039, possibly referred to a young P. eurydices by Villa et al. (2016). However, the Hambach 6C specimen has more teeth than the latter. IPB-HaH 2279 may thus represent a palaeobatrachid, maybe even related to P. eurydices, but in absence of further, better preserved and more taxonomically significant, material from the Miocene level of Hambach, it appears more confident to propose only a cautious identification.</p></div>	https://treatment.plazi.org/id/03F52665D04EFF93FEF79EE2FCD174ED	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	Villa, Andrea;Macaluso, Loredana;Mörs, Thomas	Villa, Andrea, Macaluso, Loredana, Mörs, Thomas (2024): Miocene and Pliocene amphibians from Hambach (Germany): New evidence for a late Neogene refuge in northwestern Europe. Palaeontologia Electronica (a 3) 27 (1): 1-56, DOI: 10.26879/1323, URL: http://dx.doi.org/10.26879/1323
03F52665D04FFF93FE9D9B21FC24716D.text	03F52665D04FFF93FE9D9B21FC24716D.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Eopelobates Parker 1929	<div><p>EOPELOBATES Parker, 1929</p><p>cf. Eopelobates sp.</p><p>Figure 19 A-J</p><p>Material. Hambach 11: one sacral vertebra (IPB-HaR 2179); one humerus (IPB-HaR 2154); two ilia (IPB-HaR 2084, IPB-HaR 2103).</p><p>Description. IPB-HaR 2179 (Figure 19 A-D) is a moderately small sacral vertebra and has an amphicoelous and cylindrical centrum. The neural canal is circular and the dorsal surface of the neural arch is smooth. Both the prezygapophyses and the transverse processes are broken off. The latter are anteroposteriorly extended.</p><p>IPB-HaR 2154 (Figure 19 E-F) is a poorly preserved humerus provided with a curved diaphysis (though it is broken and misses the proximal portion) and an eminentia capitata that is shifted laterally compared to the main axis of the bone. A deep fossa cubitalis ventralis is present; it opens on the lateral side. There are no cristae medialis and lateralis.</p><p>Ilia (Figure 19 G-J) lack a dorsal tubercle and a dorsal crest. They have an acetabular fossa provided with a strong anteroventral rim. The dorsal acetabular expansion is rather short. No supraacetabular fossa, preacetabular fossa, interiliac groove, or interiliac tubercle are visible. The spiral groove is not distinct. The posterior end of the bone is slightly eroded in both specimens, but very light striae are visible on their posteromedial surface.</p><p>Remarks. Few elements from Hambach 11 are attributed to Pelobatidae because of the following combination of features (Bailon, 1999; Roček, 2013): curved diaphysis of the humerus; laterallyshifted eminentia capitata; deep fossa cubitalis ventralis, which is open laterally; ilia with no dorsal crest and no dorsal tubercle; no preacetabular and supracetabular fossae; striae on the medial side of the ilial body. Within pelobatids, the absence of a deep spiral (or oblique) groove is used to distinguish Eopelobates from Pelobates Wagler, 1830 (Böhme, 2010; Syromyatnikova, 2019), and thus these fossils are here assigned to the former genus. However, this identification is only considered tentative here, because not all authors deem isolated postcranial elements sufficient for genus level discrimination (Rage and Roček, 2003). Known Eopelobates species are all based on articulated material (Roček et al., 2014), making comparison with the disarticulated specimens from Hambach difficult. Furthermore, most of the diagnostic features of the species are on cranial elements. Nevertheless, at least Eopelobates deani Roček et al., 2014, and Eopelobates grandis Zweifel, 1956, seem to differ from the Hambach ilia in the low dorsal tubercle and the low dorsal crest in the anterior portion of the shaft respectively. The sacral vertebra IPB-HaR 2179 is also tentatively attributed to cf. Eopelobates sp. because of the cylindrical centrum and the extended transverse processes, as well as the presence of the spinal foramina. In pelobatids, sacral vertebrae not fused to the urostyle are present in both Eopelobates and Pelobates (Bailon, 1999; Roček et al., 2014; Syromyatnikova, 2017). However, vertebrae of pelobatids are usually procoelous. Amphicoelous vertebrae, followed by a cartilaginous disk, are known only in E. grandis (even though its referral to Eopelobates is called into question by some authors also because of this feature; Roček et al., 2014). The holotype and only known specimen of E. grandis does not preserve the sacral centrum or the anterior part of the urostyle, and so an amphicoelous condition of the former cannot be evaluated. Amphicoelous sacral centra are shown by Ascaphus Stejneger, 1899, and some extinct Mesozoic frogs (Reilly and Jorgensen, 2011), but accounting for the absence of any existing evidence supporting the possible presence of the North American ascaphids in Europe at any moment in time as well as the highly unlikely circumstance of a survival of an early-branching Mesozoic anuran lineage in the Pliocene of the continent, we here consider more probable that IPB-HaR 2179 could represent a pelobatid with either a peculiar vertebral morphology or an anomalous condition due to ontogenetic or pathologic circumstances.</p></div>	https://treatment.plazi.org/id/03F52665D04FFF93FE9D9B21FC24716D	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	Villa, Andrea;Macaluso, Loredana;Mörs, Thomas	Villa, Andrea, Macaluso, Loredana, Mörs, Thomas (2024): Miocene and Pliocene amphibians from Hambach (Germany): New evidence for a late Neogene refuge in northwestern Europe. Palaeontologia Electronica (a 3) 27 (1): 1-56, DOI: 10.26879/1323, URL: http://dx.doi.org/10.26879/1323
03F52665D049FF95FE279D2CFC18746E.text	03F52665D049FF95FE279D2CFC18746E.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Pelobatidae Bonaparte 1850	<div><p>Pelobatidae indet.</p><p>Figure 19 P-U</p><p>Material. Hambach 6C: one trunk vertebra (IPB-HaH 2220); one humerus (IPB-HaH 2399).</p><p>Discussion. IPB-HaH 2220 (Figure 19 P-S) is a moderately large-sized and procoelous trunk vertebra. It has a cylindrical centrum and a long neural arch, with a low carina neuralis and a well-developed posterior point. Transverse processes are broken off, but they were located under the prezygapophyses.</p><p>The humerus (Figure 19 T-U) is small, but preserves part of the diaphysis and part of the epiphysis. The eminentia capitata is shifted laterally. A shallow fossa cubitalis ventralis, which is open on the lateral side, is present. The epicondyles are missing. The cristae medialis and lateralis are not developed. On the dorsal side, the visible part of the olecranon scar is poorly marked.</p><p>Remarks. Following Bailon (1999), these two fossils can be assigned to pelobatids. This attribution is based on: vertebra procoelous, with a long neural arch, transverse processes located ventral to the prezygapophyses, a cylindrical centrum, and a well-developed posterior point; humerus with a laterally-open fossa cubitalis ventralis and maybe also lateral shift of the eminentia capitata. The absence of more taxonomically significant elements in the Miocene level of Hambach, however, hinders a discrimination of either Eopelobates or Pelobates .</p></div>	https://treatment.plazi.org/id/03F52665D049FF95FE279D2CFC18746E	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	Villa, Andrea;Macaluso, Loredana;Mörs, Thomas	Villa, Andrea, Macaluso, Loredana, Mörs, Thomas (2024): Miocene and Pliocene amphibians from Hambach (Germany): New evidence for a late Neogene refuge in northwestern Europe. Palaeontologia Electronica (a 3) 27 (1): 1-56, DOI: 10.26879/1323, URL: http://dx.doi.org/10.26879/1323
03F52665D04AFF96FC199902FC0B75F8.text	03F52665D04AFF96FC199902FC0B75F8.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Bufo bufo (Linnaeus 1758)	<div><p>BUFO BUFO (Linnaeus, 1758)</p><p>Bufo gr. bufo</p><p>Figure 21</p><p>Material. Hambach 11: one sacral vertebra (IPB-HaR 2020).</p><p>Description. IPB-HaR 2020 is a medium-sized sacral vertebra provided with an anterior cotyle and two posterior condyles. The neural canal is subelliptical. A low carina neuralis is present on the dorsal surface of the neural arch, whereas there are no fossettes. Transverse processes are broken and so it is not easy to evaluate their complete anteroposterior extension. Nevertheless, the preserved bases suggest that they were not cylindrical and also not strongly expanded.</p><p>Remarks. This sacral vertebra is here attributed to a representative of the common toad species group due to (Bailon, 1999): presence of an anterior cotyle; transverse processes not strongly extended; presence of a carina neuralis; and absence of fossettes on the dorsal surface of the neural arch.</p></div>	https://treatment.plazi.org/id/03F52665D04AFF96FC199902FC0B75F8	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	Villa, Andrea;Macaluso, Loredana;Mörs, Thomas	Villa, Andrea, Macaluso, Loredana, Mörs, Thomas (2024): Miocene and Pliocene amphibians from Hambach (Germany): New evidence for a late Neogene refuge in northwestern Europe. Palaeontologia Electronica (a 3) 27 (1): 1-56, DOI: 10.26879/1323, URL: http://dx.doi.org/10.26879/1323
03F52665D074FFA8FE309AC3FA7F74B3.text	03F52665D074FFA8FE309AC3FA7F74B3.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Ranidae Batsch 1796	<div><p>Ranidae indet.</p><p>Figure 22 G-N</p><p>Material. Hambach 6C: nine sacral vertebrae (IPB-HaH 2193/2194, IPB-HaH 2209/2215); one scapula (IPB-HaH 2323). Hambach 11: one trunk vertebra (IPB-HaR 2184); three sacral vertebrae (IPB-HaR 2018/2019; IPB-HaR 2031); one ilium (IPB-HaR 2087).</p><p>Description. IPB-HaR 2184 is a small and amphicoelous trunk vertebra, with a short neural arch and laterally directed transverse processes.</p><p>Sacral vertebrae (Figure 22 G-J) are small and provided with one anterior and two posterior condyles. They have cylindrical transverse processes.</p><p>IPB-HaH 2323 (Figure 22 K-L) is an elongated scapula. It has no ridges on the anterior margin, but it is provided with a ridge on the inner surface. The cavitas glenoidalis opens in posterior direction and is partially hidden by the pars acromialis in ventral view.</p><p>The ilium (Figure 22 M-N) is small and poorly preserved, missing completely the shaft. It has a large and subcircular acetabular fossa. Dorsal to the latter, a deep supraacetabular fossa is present. The dorsal tubercle is also present, even though mostly broken away. Nevertheless, it appears moderately distinct. Anteriorly, it is in continuation with a dorsal crest. Both the dorsal and ventral acetabular expansions are broken, but the former appears well developed based on what is preserved. Medially, there is no interiliac groove or tubercle. The ilioischiatic juncture seems rather low and large, but it is not completely preserved.</p><p>Remarks. All these specimens present a combination of features supporting attribution to indeterminate ranids according to the criteria presented by Bailon (1999). For the trunk vertebra, this combination includes amphicoely, the short neural arch, and the laterally directed processes; this further suggests that it represents the eighth vertebra in the column (Bailon, 1999). In the sacral vertebra, the diagnostic combination consists of the anterior condyle, the two posterior condyles, and the cylindrical processes. For the scapula, significant are the elongation, the absence of crista anterior, the cavitas glenoidalis hidden in ventral view, as well as the presence of an inner ridge on scapula. The attribution of the ilium is supported by the presence of the dorsal crest and the absence of interiliac tubercles and grooves. The low and large juncture could hint at green frogs for the ilium (Gleed-Owen, 1998), but it is not clear how much this apparent morphology may be influenced by the preservation.</p></div>	https://treatment.plazi.org/id/03F52665D074FFA8FE309AC3FA7F74B3	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	Villa, Andrea;Macaluso, Loredana;Mörs, Thomas	Villa, Andrea, Macaluso, Loredana, Mörs, Thomas (2024): Miocene and Pliocene amphibians from Hambach (Germany): New evidence for a late Neogene refuge in northwestern Europe. Palaeontologia Electronica (a 3) 27 (1): 1-56, DOI: 10.26879/1323, URL: http://dx.doi.org/10.26879/1323
03F52665D074FFA9FB8A9AE3FDCE7071.text	03F52665D074FFA9FB8A9AE3FDCE7071.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Anura Fischer 1813	<div><p>Anura indet.</p><p>Material. Hambach 6C: four premaxillae (IPB-HaH 2268/2270, IPB-HaH 2299); 51 fragments of maxilla (IPB-HaH 2233/2265, IPB-HaH 2282/2298, IPB-HaH 2300); 17 trunk vertebrae (IPB-HaH 2089/2097, IPB-HaH 2144/2145, IPB-HaH 2157/ 2158, IPB-HaH 2181/2183, IPB-HaH 2192); seven sacral vertebrae (IPB-HaH 2087, IPB-HaH 2206/ 2208, IPB-HaH 2217/2218, IPB-HaH 2225); 12 urostyles (IPB-HaH 2088, IPB-HaH 2197/2198, IPB-HaH 2201/2205, IPB-HaH 2216, IPB-HaH 2226/2227, IPB-HaH 2306); three coracoids (IPB-HaH 2313/2314, IPB-HaH 2378); nine humeri (IPB-HaH 2063, IPB-HaH 2303/2304, IPB-HaH 2311/ 2312, IPB-HaH 2317/2318, IPB-HaH 2331); five radioulnae (IPB-HaH 2301/2302, IPB-HaH 2309, IPB-HaH 2330, IPB-HaH 2335); two ilia (IPB-HaH 2319/2320); one ischium (IPB-HaH 2322); one femur (IPB-HaH 2326); 14 tibiofibulae (IPB-HaH 2054, IPB-HaH 2062, IPB-HaH 2064/2068, IPB-HaH 2305, IPB-HaH 2310, IPB-HaH 2327, IPB-HaH 2332/2334, IPB-HaH 2400); four indeterminate elements (IPB-HaH 2308, IPB-HaH 2315, IPB-HaH 2328, IPB-HaH 2398). Hambach 11: 29 maxillae (IPB-HaR 2044/2070, IPB-HaR 2177/ 2178); one angular (IPB-HaR 2114); two atlases (IPB-HaR 2025, IPB-HaR 2035); five trunk vertebrae (IPB-HaR 2024; IPB-HaR 2027/2029; IPB-HaR 2037); two sacral vertebrae (IPB-HaR 2026, IPB-HaR 2036); three urostyles (IPB-HaR 2038/ 2040); two coracoids (IPB-HaR 2125/2126); two scapulae (IPB-HaR 2072/2073); 10 humeri (IPB-HaR 2089/2095, IPB-HaR 2108/2109, IPB-HaR 2153); 16 radioulnae (IPB-HaR 2074/2079, IPB-HaR 2107, IPB-HaR 2123/2124, IPB-HaR 2128, IPB-HaR 2155/2157, IPB-HaR 2180/2182); four ilia (IPB-HaR 2085/2086, IPB-HaR 2104/2105); one ischium (IPB-HaR 2106); three femurs (IPB-HaR 2133/2134, IPB-HaR 2141); 25 tibiofibulae (IPB-HaR 2080/2082, IPB-HaR 2118/2122, IPB-HaR 2135/2140, IPB-HaR 2158/2168); one indeterminate element (IPB-HaR 2169). Hambach 11C: three maxillae (IPB-HaR 2422/2424); one ornamented bone fragment (IPB-HaR 2430); four tibiofibulae (IPB-HaR 2410/2413); one indeterminate element (IPB-HaR 2409).</p><p>DISCUSSION</p><p>The Middle Miocene and Late Pliocene Amphibians from Hambach Compared</p><p>Deposition of the two fossiliferous levels in Hambach, stratum 6C (with site Hambach 6C) and stratum 11 (with sites Hambach 11 and 11C), is separated by about a dozen Myr and happened in very different global climatic contexts (the MCO vs a period of climate deterioration preceding the onset of Quaternary glacial cycles). This is clearly reflected in the faunal composition, with a far higher diversity in the Middle Miocene association compared to the Late Pliocene one and the presence of several taxa linked with subtropical conditions in the former (e.g., among amphibians and reptiles: cryptobranchids, Chelydropsis, Diplocynodon Pomel, 1847, cobras). Based on our observations and identifications (Table 1), the amphibian component of the Hambach faunas matches with this pattern, all in all. The Middle Miocene fossil assemblage from Hambach 6C includes at least six different urodeles and six anurans. The Hambach 11 and 11C combined assemblage, on the other hand, listed only half the number of urodeles, even though the total of recognized anurans amounts to the same value. The remains attributed to the indeterminate cryptobranchid and to Chelotriton stand as evidence of the already-mentioned “tropical” elements present during the Middle Miocene. In agreement with crocodylians (Mörs et al., 2000; Mörs, 2002) and cobras (Čerňanský et al., 2017), but in contrast with what happens with Chelydropsis turtles (which possibly persisted in the Upper Pliocene deposits; Mörs, 2002), the two urodeles are absent in younger sites at Hambach, hinting towards a likely extirpation between MN 5 and MN 16a. Other urodeles sharing the same pattern of a Miocene presence and Pliocene absence in Hambach include Euronecturus grogu and Triturus sp. It is interesting to note that the proteid E. grogu, of which Hambach 6C is the only occurrence known worldwide at the moment, seems to be replaced by Mioproteus, a member of a different “modern” lineage of Eurasian proteids (Macaluso et al., 2022b). The ranid frogs Pelophylax sp. and Rana sp. are also recognized in Hambach 6C only, but the presence of ranids in the Upper Pliocene as well is attested by few remains from Hambach 11. At least one of these remains, the ilium IPB-HaR 2087, may even display green frog features, and thus the absence of either one or the two ranids from the younger assemblage may be artifactual.</p><p>Remarks. Numerous fossil elements can be assigned to anurans, but are either too poorly preserved or not taxonomically significant enough for a more refined identification.</p><p>Reptiles</p><p>While studying the amphibian material, we chanced upon a few remains of reptiles that were accidentally not included in Čerňanský et al.’s (2017) work. Most of these are fragments of poorly diagnostic bones, but at least two specimens are worth mentioning and figuring. IPB-HaH 2340 (Figure 23 A-B), from Hambach 6C, is probably a fragment of the posterodorsal process of a right jugal. The ornamentation recalls Chamaeleo andrusovi Čerňanský, 2010, even though the topotypic jugals of this species show two rows of protuberances instead of just one as in the case of the specimen from Hambach. It is here attributed to Chamaeleo aff. andrusovi, similar to the squamosal fragment described by Čerňanský et al. (2017) from the same site. IPB-HaR 2171 (Figure 23 C-D), from Hambach 11, can be associated to the same taxon as the nasal assigned by Čerňanský et al. (2017) to Pseudopus cf. pannonicus (Kormos, 1911), because they share a similar dermal sculpturing.</p><p>Nevertheless, there are also amphibians clearly persisting in Hambach in both Middle Miocene and Late Pliocene times. These include at least two urodeles, Palaeoproteus cf. miocenicus and Lissotriton sp., and two anurans, Latonia sp. and Hyla sp. As mentioned, ranids can also be added to this list, even though detailed identification of the Pliocene remains at specific rank is prevented. Among frogs, palaeobatrachids and pelobatids show the reverse situation, with Late Pliocene remains that can be identified at species ( P. eurydices) or, possibly, genus (cf. Eopelobates sp. and? Eopelobates sp.) ranks respectively, whereas only the general presence of the families can be reported for the Middle Miocene (even in a tentative way in the case of palaeobatrachids). On the opposed side, the toad Bufo gr. bufo is the only anuran whose presence is certified just for the Late Pliocene in Hambach. Therefore, considering the uncertainty surrounding the possible persistence of some taxa from the Middle Miocene, the composition of the Late Pliocene Hambach 11 and 11C amphibian assemblage is certainly impoverished compared to the older one from Hambach 6C, apparently mainly as far as the urodele component is concerned, but it appears to exhibit an overall similarity and continuity. This differs from other tetrapod groups, which are sporadically represented by the same or related taxa in both Miocene and Pliocene levels (e.g., some petauristid rodents and possibly the already-mentioned Chelydropsis turtles; Mörs et al., 2000; Mörs, 2002; Van Laere and Mörs, 2023).</p><p>In terms of abundance, the highest numbers of remains identified per taxon in the Miocene assemblage are those referred to Chelotriton sp. (57 remains) and Latonia sp. (37 remains). These are, therefore, the taxa dominating the oldest Hambach oryctocenosis. Latonia persisted as dominant also in the Pliocene with 22 remains (18 from Hambach 11 and six from Hambach 11C), following P. eurydices represented by 27 remains (23 and four from Hambach 11 and 11C, respectively). As already mentioned, Chelotriton is not present in the Pliocene 11 and 11C sites, in agreement with a general European trend of extinction of this newt. The only Pliocene remains referred to this genus come in fact from the Upper Pliocene of southern France (Bailon, 1989; Macaluso et al., 2022a). The most-represented urodele in the Upper Pliocene of Hambach is Mioproteus cf. wezei, represented by 15 remains (nine and six, respectively, from Hambach 11 and 11C). Other taxa from both the Miocene and Pliocene assemblages are only represented by very few, less than 10 remains each (except for Triturus sp., with 12). Thus, these represent only very minor components of the fossil associations.</p><p>Palaeobiogeographical Significance of the Hambach Amphibian Assemblages</p><p>The amphibian fossil record from Hambach already proved to host unexpected surprises with the discovery of Euronecturus grogu, an enigmatic proteid (see Macaluso et al., 2022b) that is only known from its type locality of Hambach 6C at the moment. The extended study of the whole amphibian record revealed that this is not the only noteworthy taxon preserved in the site, and that significant findings were hidden in both the Miocene and Pliocene assemblages.</p><p>Cryptobranchids are in general poorly represented in the fossil record, even though a particular concentration of Neogene cryptobranchid-bearing sites is found in central Europe, and more specifically in Southern Germany (Böhme et al., 2012). Still, they are almost unknown from the European early Middle Miocene, even though their presence in Lower, upper Middle and Upper Miocene sites (Westphal, 1958, 1970; Böttcher, 1987; Miklas, 2002; Böhme, 2003; Kvaček et al., 2004; Tempfer, 2004; Böhme et al., 2012; Vasilyan et al., 2013; Sach, 2016; Georgalis et al., 2019b; Szentesi et al., 2020) suggests their continuous persistence in the continent. As a matter of fact, Hambach 6C is currently the only known occurrence of a cryptobranchid from the early Middle Miocene time frame in Europe, and even adds to a limited Eurasian Langhian record that further includes only few localities in Kazakhstan (Chkhikvadze, 1982; Böhme et al., 2012). Cryptobranchids later declined in Europe during the Pliocene, with their last occurrence at Willershausen, in central Germany (Westphal, 1967; Böhme et al., 2012). The age of Willershausen was reported as Zanclean by Böhme et al. (2012, table 1), but it is now considered as Piacenzian (Kolibáč et al., 2016, and reference therein). Adding to being the only data currently available on European early Middle Miocene cryptobranchids, Hambach 6C represents also the westernmost point ever reached by these urodeles in Eurasia, based on our current knowledge. Only the late Oligocene occurrence at Rott (Westphal, 1958; Mörs, 2002; Böhme et al., 2012), close but located slightly eastward to Hambach, further supports the past existence of cryptobranchid populations west of the Rhine Graben.</p><p>One of the most unexpected findings from Hambach is the batrachosauroidid Palaeoproteus . Batrachosauroidids are enigmatic urodeles, which are mainly known from the Cretaceous and Palaeogene of North America (Gardner and DeMar, 2013, and reference therein). They persisted in the USA throughout the Miocene, with a handful of occurrences in California (Naylor, 1981), Delaware (Weems and George, 2013), Florida (Estes, 1963; Bryant, 1991), Louisiana (Williams, 2009), and Texas (Taylor and Hesse, 1943; Auffenberg, 1958; Hinderstein and Boyce, 1977; Holman, 1977; Albright, 1994). They are also known from Europe, even though their record on this continent is far poorer. They were possibly present already during the Cretaceous (Duffaud, 1995; Evans and Milner, 1996; Evans and McGowan, 2002), and then are seldomly recovered in the Palaeocene (Estes et al., 1967; Groessens-Van Dyck, 1981), Eocene (Herre, 1935), and Upper Miocene (Vasilyan and Yanenko, 2020). A single record from the Lower Miocene is also reported (Böhme, 2003; Kvaček et al., 2004), but detailed descriptions and identification of these fossils remain unpublished so far. Similar to the cryptobranchids, the Hambach 6C Palaeoproteus remains are the only batrachosauroidid fossils currently known from the Middle Miocene in Europe. Adding to this, those coming from Hambach 11 and 11C further stand out as the youngest occurrence of this clade worldwide, as well as the only one postdating the Miocene/Pliocene transition. Moreover, Hambach lists among the northernmost sites reached by these urodeles in post-Palaeogene times, being located even slightly more northward than Hrytsiv in Ukraine (Vasilyan and Yanenko, 2020) and Ahníkov/Merkur North in Czech Republic (where the presence of these amphibians can be seen as unconfirmed, for the time being; Böhme, 2003; Kvaček et al., 2004). Both the Miocene and Pliocene Hambach material is here referred to the European genus Palaeoproteus, and even to a taxon related to the species P. miocenicus . Even though a confident identification of the fossils with this Late Miocene species is currently prevented, Hambach is evidence that either one or two morphologically similar forms (depending on whether occurrences from Hambach 6C and Hambach 11 and 11C are conspecific or not) were already present in Europe several Myr before the oldest occurrence reported by Vasilyan and Yanenko (2020) and successively persisted at least up to slightly before the Plio-Pleistocene boundary.</p><p>Euronecturus is not the only proteid found in Hambach: Mioproteus, a possible representative of a modern European clade including also the extant Proteus (Macaluso et al., 2022b), actually replaced it in the youngest level. Several other occurrences of Mioproteus are known from Germany throughout the Miocene (Schleich, 1985; Böhme, 2003; Böttcher et al., 2009; Prieto et al., 2009; Abdul Aziz et al., 2010; Sach, 2016; Macaluso et al., 2022a, 2022b), including fossils referred to both M. caucasicus and indeterminate species (even though most of these were never properly published). Its absence in Hambach 6C, thus, appears puzzling per se, especially when paired with the presence of Euronecturus . Some sort of competitive exclusion cannot be discounted, even though only treated as speculative at the moment due to the very poor information we have about the latter. Later on, Mioproteus survived up to the late Early Pleistocene (Młynarski and Szyndlar, 1989; Averianov, 2001; Ivanov, 2007), but all findings postdating the Miocene/Pliocene transition are either unassigned to species (Averianov, 2001; Ratnikov, 2010; Vasilyan et al., 2017) or referred to M. wezei (Młynarski et al., 1984; Młynarski and Szyndlar, 1989; Bailon, 1995; Averianov, 2001; Ivanov, 2007; Syromyatnikova et al., 2021, Macaluso et al., 2022a). If our identification is correct, the Upper Pliocene occurrence of Mioproteus cf. wezei in Hambach would agree with this pattern. Furthermore, this is currently one of the westernmost records of Mioproteus, with only M. wezei from Balaruc II, in France (Bailon, 1995), located in an even more western position (even though in a far more southern, Mediterranean area).</p><p>Among salamandrids, Chelotriton is the most represented in Hambach 6C and also very common in Europe, and even in Germany, during the Miocene. Hambach lists among the northernmost Miocene occurrences reached by the genus on the continent, together with the slightly more southern remains from Echzell (Vasilyan et al., 2022). These large salamandrids apparently decreased after the Messinian Salinity Crisis. They are reported from the post-evaporitic succession of Moncucco Torinese in Italy (Colombero et al., 2017), and subsequently the only published occurrence is from the Upper Pliocene of Balaruc II in France (Bailon, 1989). Their absence in Hambach 11 and 11C agrees with this observed pattern of extirpation from northern Europe possibly somewhen in the Late Miocene, and in any case before the Late Pliocene (Macaluso et al., 2022a). Triturus newts also are represented in Hambach 6C only in our material, even though, in contrast with Chelotriton, their presence as far north as central Germany (Holman, 1998; Böhme, 2000, 2020) and The Netherlands (Villa et al., 2018c) in northwestern Europe is known up to the Quaternary. The genus still persists nowadays in the area of Hambach with the species T. cristatus (Sillero et al., 2014; Speybroeck et al., 2016). Few published Triturus dated back to MN 5 are also reported in Europe only from southern Germany (Böttcher et al., 2009), but other occurrences from Czech Republic and Germany were mentioned by Böhme (2003) without figures or detailed descriptions. The Hambach specimens add, thus, to the rather poor knowledge of these newts at the Early/Middle Miocene transition. Further significance can be given to the Miocene Lissotriton remains from Hambach 6C, given that these stand out among the oldest occurrences of the genus. Older remains were found in two upper Oligocene sites in southern France (Macaluso et al., 2022a) and southern Germany (Böhme 2008), as well as in the Lower Miocene of southern France (two sites; Rage and Hossini, 2000; Rage and Bailon, 2005), western Germany (one site; Vasilyan et al., 2022), and southern Germany (two sites; Böttcher et al., 2009; Böhme, 2010). Macaluso et al. (2022a) further mentioned possible Lissotriton identity for lower Eocene vertebrae from France (Augé et al., 1997), but this has yet to be confirmed. Several other localities yielding Early and Middle Miocene Lissotriton remains in Germany (possibly going back even to the Oligocene/ Miocene transition) were listed by Böhme (2003), but these fossils still await proper publication. On the other hand, the very few vertebrae from Hambach 11 represent the first Pliocene Lissotriton remains found in Germany, where otherwise occurrences in the country date to either Miocene or Quaternary. Very few further Late Pliocene remains come from Poland (Sanchiz and Młynarski, 1979b; Młynarski and Szyndlar, 1989) and Spain (Gómez de Soler et al., 2012).</p><p>Anurans from Hambach also include very common taxa in Europe during corresponding time frames, as well as unexpected occurrences. The most abundant anuran in Hambach, Latonia, is very common all over Europe, including Germany, during most of the Neogene (Roček, 1994b, 2013, and reference therein). It is far less distributed on the continent during the Late Pliocene, when only few occurrences in southern France (Bailon, 1991), central Germany (Böhme, 2000), northern Italy (Vergnaud-Grazzini, 1970), and southern Ukraine (Ratnikov, 2001) are known. In the Pleistocene, relict occurrences of this alytid genus in Europe are only reported from northern Hungary (Szentesi, 2019) and central Italy (Sorbelli et al., 2021). Early Pleistocene Latonia remains were also found in Turkey (Vasilyan et al., 2014), but late Quaternary occurrences are limited to Israel (Biton et al., 2016), where the last survivors of these frogs were recently rediscovered (Biton et al., 2013; Perl et al., 2017). After the Miocene/Pliocene boundary, the German site of Kaltensundheim is the only place where Latonia was reported (Böhme 2000) that reaches comparable northern latitudes with Hambach. However, Böhme (2002) found no trace of Latonia among the fossil material from this Thuringian site and recommended its removal from the taxon list of the assemblage. Thus, Hambach currently stands as the northernmost confirmed occurrence of Latonia from the late Neogene onwards.</p><p>Palaeobatrachids are almost completely absent from western Europe following the Miocene/Pliocene transition (Wuttke et al., 2012; Roček, 2013; Roček et al., 2021), with the only notable exceptions being Tegelen, in The Netherlands (Villa et al., 2016), and Hambach 11 and 11C. These localities share the same palaeobatrachid species, which is currently not known elsewhere, and are geographically close, even though the Dutch site is younger, being Lower Pleistocene (Gelasian) in age. Other Pliocene and Quaternary occurrences of palaeobatrachids are all located far eastward. The closest one in geographical terms to Tegelen and Hambach, and only other post-Miocene site with palaeobatrachids in Germany, is possibly Voigtstedt, a Chibanian locality in Thuringia, from which Palaeobatrachus langhae (Fejérváry, 1917) was reported by Kretzoi (1965) and later mentioned as a tentative occurrence by Holman (1998), Sanchiz (1998), and Böhme (2000). There is no other Miocene occurrence of palaeobatrachids in the northwestern part of continental Europe surrounding Hambach and Tegelen (Wuttke et al., 2012), and the estimated closest relatives to the Plio-Pleistocene species P. eurydices are to be found in the Lower Miocene of southern France and central Germany ( Palaeobatrachus robustus Hossini and Rage, 2000; Hossini and Rage, 2000; Roček, 2013; Villa et al., 2016; Roček et al., 2021; Vasilyan et al., 2022). In this context, the fragmentary maxilla from Hambach 6C testifies that these water-dwelling frogs likely inhabited the area during the early Neogene as well, even though the preservational status prevents both a confident attribution at family rank and even more any inference on the possible persistence of the lineage leading to P. eurydices . More Neogene palaeobatrachid fossils from countries such as Belgium, The Netherlands, and (northwestern) Germany are needed to shed light on the early evolution of this possibly relictual lineage.</p><p>A situation similar to that of palaeobatrachids arises for pelobatids from Hambach as well. Several pelobatids are reported from the Palaeogene and Neogene of Europe (e.g., Sanchiz, 1998; Roček, 2013; Vergilov and Tzankov, 2021; and reference therein), but only few of them come from the northwestern part of the continent, where Hambach is located. Miocene pelobatids found in the area come from only three localities placed slightly eastward to the latter site: an Aquitanian indeterminate member of the family from Budenheim, near Mainz, mentioned, but neither described nor figured, by Schleich (1988); several Burdigalian remains of Pelobates sanchizi Venczel, 2004 from Echzell (Vasilyan et al., 2022); and a Middle Miocene premetamorphic tadpole from Climbach, near Allendorf, attributed to Eopelobates sp. (originally referred to Palaeobatrachus goldfussi Tschudi, 1838 by von Meyer, 1860, but later reidentified by Špinar, 1972; see Gardner, 2016). The two fossil bones from Hambach 6C are evidence that the range of pelobatids extended further west in this part of Europe in the Middle Miocene, but it is currently impossible to figure out whether or not they were related to either the taxa living in nearby areas in Palaeogene times (e.g., Eopelobates bayeri Špinar, 1952 from Belgium, Eopelobates wagneri (Weitzel, 1938) from western Germany; Roček, 2013; Roček et al., 2014; Smith et al., 2018), the Early/Middle Miocene above-mentioned ones from western Germany, or even those from the youngest level in Hambach. If correctly identified, the Late Pliocene Eopelobates from Hambach 11 and 11C, on the other hand, shares potentially no relations with other pelobatids identified at genus rank in close-by post-Miocene sites. Known congeneric occurrences postdating the Miocene/ Pliocene transition are all located in Eastern Europe (Młynarski 1962; Sanchiz and Młynarski, 1979a; Młynarski and Szyndlar, 1989; Ratnikov, 2001; Venczel, 2001; Roček, 2013; Roček et al., 2014; Vergilov and Tzankov, 2021), even though Rage and Roček (2003), Roček (2013), and Vergilov and Tzankov (2021) recommended caution on these occurrences due to the absence of the most diagnostic cranial elements in the respective material. Nevertheless, only Pelobates is recorded in the western part of the continent in the last 5 Myr. Apart from the fossils from Hambach, the other youngest published records of Eopelobates in western Europe are Middle Miocene in age (Špinar, 1972; Böhme, 2010; Roček et al., 2014; Gardner, 2016). If our identification is correct, the possible Late Pliocene Hambach Eopelobates is, thus, another unexpected late survivor from the site. Available published evidence suggest that Eopelobates went extinct before the beginning of the Pleistocene (but see Rage and Roček, 2003, and Vergilov and Tzankov, 2021, for an older extinction date), which agrees with the fact that Quaternary sites in the area close to Hambach only yielded Pelobates (Böttcher, 1991; Holman, 1998; Sanchiz, 1998; Schouten, 2016; Villa et al., 2018c).</p><p>Taking into account their rather fragile skeleton, tree frogs of the genus Hyla are rather common in European sites from the Miocene onwards, especially during the Quaternary. Earliest European representatives of the genus possibly entered the continent in the Early Miocene (Sanchiz and Roček, 1996; Rage and Roček, 2003; Roček, 2013), together with several other amphibians and reptiles (Szyndlar and Schleich, 1993; Ivanov, 2000; Delfino et al., 2003; Rage and Roček, 2003; Rage, 2013; Georgalis et al., 2016; Ivanov et al., 2018; Villa et al., 2018a; Villa and Delfino, 2019; Macaluso et al., 2022a). In this context, tree frogs from Hambach represent one of the oldest occurrences in Germany, together with Oggenhausen 2 in Baden-Württemberg (Böttcher et al., 2009), but also the westernmost location reached in Europe by these frogs during the Neogene based on the current published knowledge (even though, again, bones of tree frogs are very fragile and maybe subject to a strong preservation bias). Hambach is also the first German site yielding Pliocene tree frog remains. Subsequently, tree frogs persisted in the area, as testified at least by the members of the H. arborea group found in Tegelen (Villa et al., 2018c). They are widespread throughout northwestern Europe nowadays (Sillero et al., 2014; Speybroeck et al., 2016).</p><p>Bufonids and ranids are also inhabitants of modern northwestern Europe, as well as common findings in Neogene and Quaternary fossil assemblages in the continent. Hambach stands out as one of the northernmost known occurrences of the common toad in Pliocene times, together with Kaltensundheim in Germany (Böhme, 2002) and at least Węże 2 in Poland (Młynarski et al., 1984). Both the common toad and the two ranids were found also in the Lower Pleistocene of the nearby Tegelen locality (Villa et al., 2018c).</p><p>Palaeoenvironmental Insights and the Role of Northwestern Europe as a Late Neogene Refugial Area for Amphibians</p><p>The Hambach palaeofaunas, and especially their amphibian components, appear rather significant for their composition, with representatives of enigmatic and poorly known taxa and unexpected occurrences both in chronological and geographical terms. The palaeoenvironments in which these palaeofaunas lived were certainly humid ones. In addition to sedimentological and palaeobotanical evidence (see Geological setting), these humid conditions are testified by the rather high diversity of amphibians and the presence of other water-related animals (e.g., fish, pond turtles, Natrix Laurenti, 1768 snakes, dominant aquatic/semiaquatic forms among the insectivores, beavers; Mörs, 2002; Čerňanský et al., 2017). As far as amphibians are concerned, permanent water bodies are indicated by the occurrences of Palaeoproteus (Herre, 1935; Vasilyan and Yanenko, 2020), palaeobatrachids, and, at least in the Pliocene level, Mioproteus (a fully aquatic taxon according to Venczel and Codrea, 2018). The extant Latonia nigriventer inhabits marshy areas in the Hula Valley, in Israel (Biton et al., 2013, 2016; Perl et al., 2017), and the abundance of Latonia in both the Miocene and Pliocene of Hambach hints towards persistent preference for similar swampy environments in past members of the clade as well. Pelobatids are fossorial anurans that suggest the availability of sandy soils in Hambach. Forested areas nearby are supported by the rare tree frogs, as well as Pliopithecus Gervais, 1849, and flying squirrel remains (Mörs, 2002; Van Laere and Mörs, 2023) for the Miocene and Pliocene, respectively.</p><p>Humidity in Hambach was particularly high during the Middle Miocene, when cryptobranchids were living in the area. As a matter of fact, these urodeles are tied to high humidity and pluviometry according to Böhme et al. (2012). A certain influx of marine conditions in an estuarine setting is highlighted by the abundant marine fish and rare cetacean remains in Hambach 6C (Mörs, 2002). This changed at the end of the Middle Miocene (Schäfer et al., 2004), long before the deposition of remains found in Hambach 11 and 11C, which only include freshwater fish and is devoid of other marine animals. Fish remains in Hambach also mark another change from slow currents and larger channels in Hambach 6C to more oxygenated waters with higher energy in Hambach 11 and 11C (Mörs, 2002). Moreover, another palaeoenvironmental differences highlighted by the faunal composition in the two Hambach levels lies in the temperature: the Miocene fauna is rich in thermophilic vertebrates, such as giant tortoises, crocodylians, chameleons, “Oriental vipers”, and possibly cobras (Mörs, 2002; Čerňanský et al., 2017), whereas these are absent in the Pliocene one. This agrees with the climate reconstruction performed for Hambach 6C based on palaeobotanical data (Utescher et al., 2000, 2002), and makes further sense when considering that the Middle Miocene fauna deposited in a greenhouse interval (the Miocene Climatic Optimum; Steinthorsdottir et al. 2021), whereas the Late Pliocene one in a period of climate deterioration.</p><p>The faunal change between Hambach 6C on one side and Hambach 11 and 11C on the other is, thus, evident in several of its components, but it seems to affect the amphibians to a lower extent. Some amphibian taxa indeed disappeared between the Middle Miocene and the Late Pliocene (i.e., cryptobranchids, the Euronecturus lineage, Chelotriton), but others persisted to even be among the last known representatives of their clades in northern/northwestern Europe ( Latonia, palaeobatrachids) or worldwide ( Palaeoproteus). The case of cryptobranchids is particularly interesting because their last reported occurrence in Europe is in Willershausen, an Upper Pliocene locality in Lower Saxony, central Germany. This makes it and Hambach 11 and 11C close or comparable in terms of both geographical position and age, leading to the question on why these urodeles are absent from the Upper Pliocene level in Hambach. The depositional environment in Willershausen was that of a large and deep lake in a sinkhole, surrounded by a hilly mesophytic woodland (Kolibáč et al., 2016, and reference therein). The reconstructed palaeoclimate was cooler than what suggested for the Miocene Hambach, but with similar precipitations (Thiel et al., 2012). Unlike other taxa present in Hambach 6C and absent in Hambach 11 and 11C, then, extirpation of cryptobranchids from there is likely not tied to a decrease in temperature, given their survival in the colder Willershausen. An alternative potential explanation may be the altitudinal distribution model proposed by Böhme et al. (2012): cryptobranchids appear generally limited to higher elevations in drier periods with low basinal relief and colonize lowland environments in hyperhumid moments with high basinal relief. Giant salamanders may have disappeared from the Lower Rhine Embayment in one of such drier periods after the Middle Miocene, whereas the more elevated area near the Willershausen lake (i.e., the Harz Mountains) was able to sustain populations of these amphibians up to at least the late Neogene.</p><p>Another locality that is worth comparing with Hambach is Tegelen, in The Netherlands (Table 2). Sediments at Tegelen were also deposited by the Rhine-Meuse river system, even though in a slightly younger, Early Pleistocene, time (van den Hoek Ostende, 2004; van den Hoek Ostende and de Vos, 2006). The Russel-Tiglia-Egypte pit at Tegelen is notable for being the type locality of P. eurydices, the palaeobatrachid species found in the Upper Pliocene level at Hambach, and for having yielded a rather diverse assemblage of amphibians and reptiles (Villa et al., 2016, 2018c). Urodeles are much more diverse in Hambach, especially in the Miocene layers. Tegelen only yielded salamandrids ( Triturus and Lissotriton), whereas Hambach has salamandrids, proteids, batrachosauroidids (both Miocene and Pliocene) and cryptobranchids (only Miocene). Among salamandrids, the presence of Chelotriton in the Miocene level of Hambach expands the ecomorphological adaptations represented by a member of this clade in this assemblage compared to Tegelen. As already mentioned, Triturus is missing in the Pliocene of Hambach, but it is present in the Pleistocene of Tegelen. Given the scarcity of the remains, it is not clear whether the absence of this newt may just be artifactual or not, though. For anurans, significant is the persistence of palaeobatrachids in all levels at Hambach and then in the Russel-Tiglia-Egypte pit at Tegelen, and especially the same species being shared between the Upper Pliocene of the former and the Lower Pleistocene of the latter. In general, the overall diversity of frog and toads appears comparable, but there are strong differences in composition of the assemblages. Latonia is the most abundant anuran in Hambach, but it is absent in Tegelen. Pelobatids are possibly represented by Eopelobates at least in the Pliocene of Hambach, whereas Pelobates is identified at Tegelen. On the other hand, the Hambach assemblages lack Bombina Oken, 1816, and Pelodytes Bonaparte, 1838, taxa otherwise present at Tegelen. Hyla, the common toad, and the ranids are shared by both the German and Dutch localities, even though less common in Hambach and restricted to specific levels as far as the toad and the ranids are concerned.</p><p>When looking at reptiles, crocodylians are absent in both the Pliocene of Hambach and at Tegelen, whereas several cranial and postcranial remains attributed to Diplocynodon were recovered in the Miocene level of the former (Mörs et al., 2000; Mörs, 2002). Turtles from Tegelen only include Emys Duméril, 1806, and Mauremys, moreover never found together in the same pit (Schreuder, 1946; van den Hoek Ostende and de Vos, 2006; Villa et al., 2018c). Hambach displays a higher diversity in the Miocene, with several distinct lineages and both aquatic/semiaquatic and terrestrial animals, but only two taxa in the Pliocene (Mörs, 2002; Klein and Mörs, 2003). Emys is shared between the Pliocene of Hambach (even though this occurrence still lacks a detailed publication, with description and figures of the remains, and should be treated with caution) and the Pleistocene of Tegelen, but Hambach misses Mauremys and Tegelen misses Chelydropsis (again, if its presence in Pliocene Hambach is confirmed). Squamate faunas from Hambach 6C and Tegelen are very different, with the former being far more diverse (especially in the snake component) and including several Palaeogene/Neogene lineages missing in Tegelen (i.e., chameleons, Eoanilius Rage, 1974, Bavarioboa Szyndlar and Schleich, 1993, cf. Falseryx Szyndlar and Rage, 2003, cf. Naja Laurenti, 1768, and the “Oriental vipers”; Čerňanský et al., 2017). A small viper is present in both, even though it is not clear if they may represent the same viper group. “Colubrine” snakes and Natrix are also shared between Tegelen and both Miocene and Pliocene levels in Hambach. However, Pleistocene and Pliocene “colubrines” remain unidentified at lower taxonomic ranks, whereas the Miocene ones include at least three different taxa (“ Coluber ” Linnaeus, 1758, Texasophis Holman, 1977, and Telescopus Wagler, 1830). Not a lot can be said about lacertids, except for them being recovered both in the Middle Miocene of Hambach (Čerňanský et al., 2017) and the Pleistocene of Tegelen (Villa et al., 2018c). Diversity seems to be comparable (two taxa), but there seems to be no evidence in Hambach of a possible green lizard as in Tegelen. Pseudopus is present in all Hambach levels (Čerňanský et al., 2017; this work) and tentatively even in Tegelen. However, Miocene and Pliocene assemblages in Hambach bear two different Pseudopus species, and it is not clear if the Tegelen one may be related to either one of the two.</p><p>It seems, thus, that a major change in the reptilian palaeofauna happened already at some point in the Middle Miocene-Late Pliocene interval, with less significant differences between the Upper Pliocene assemblage of Hambach 11 and 11C and the Lower Pleistocene ones of the Tegelen pits (and in particular the Russel-Tiglia-Egypte pit). On the other hand, differences in the batrachofauna are more marked between Hambach 11 and 11C and Tegelen compared to the two levels in Hambach. Whilst the faunal change affecting reptiles agrees with the well-recognized pattern of extirpation of thermophilic taxa from northern Europe characterizing the late Neogene and Quaternary (e.g., Delfino et al., 2007; Rage, 2013; Blain et al., 2016; Villa and Delfino, 2019), amphibians here appear to be less affected by this trend. The differences between Hambach and Tegelen in the amphibian palaeocommunity may be simply explained by different palaeoenvironments (swamp vs floodplain, respectively), but the peculiarity of the batrachofauna in Hambach 11 and 11C (with several taxa otherwise unknown from northwestern Europe in contemporary times) and its similarities with the Hambach 6C one suggest that other factors may be also at play. Reconstructed palaeoclimate at Tegelen based on the herpetofaunistic association recovered from the Russel-Tiglia-Egypte pit (Villa et al., 2018c) indicate a humid subtropical climate, but with MAT and MAP significantly lower than those at Hambach during the Middle Miocene (quantitative climate reconstructions are not available for the Upper Pliocene Hambach sites). A light degree of aridity was also suggested by the same reconstruction. No evidence of a similar dryness is available for the Upper Pliocene level in Hambach. Increased aridization was proposed as a possible cause for the disappearance of some amphibians (i.e., palaeobatrachids; Wuttke et al., 2012) from Western Europe in the late Neogene, but it is evident that areas suitable for these animals persisted at least in the northwestern part of the continent (i.e., in the Lower Rhine Embayment and the Rhine-Meuse delta system) up to the Late Pliocene and, maybe to a lower extent, the Early Pleistocene. High humidity may have allowed the Lower Rhine Embayment to act as a refuge for amphibians during this time, while they were disappearing from other parts of Western Europe. Later, a combination of increasing aridity and potentially the onset of the Quaternary glaciation may have led to the ultimate loss of the refugial conditions and to a faunistic change towards the early Quaternary and subsequent modern batrachofauna of the area. As a matter of fact, various evidence points out to different trends shown by temperatures and precipitations in the Lower Rhine Embayment during the late Neogene, with MATs showing a clear decreasing trend after the early Middle Miocene and MAPs maintaining high values (&gt; 1000 mm) well into the Pliocene (Utescher et al., 2000, 2009, 2012; van Dam, 2006; Crampton-Flood et al., 2018). Utescher et al. (2012) further observed that cool events in the Zanclean of northwestern Europe are related to, or start with, wetter conditions, in contrast with the correlation of warmer and wetter periods in the Miocene. This may have favoured the survival of amphibians in this area. In a somehow similar way, a persistent humid climate allowed the Italian Peninsula to act as a preferential refuge for amphibians during the Quaternary glacial cycles, versus the role of reptile refuges that was played by the more arid Balkan and Iberian peninsulae (Macaluso et al., 2021, 2023a). A comparable role may be advocated for the Lower Rhine Embayment as well during the late Neogene and maybe the Early Pleistocene.</p></div>	https://treatment.plazi.org/id/03F52665D074FFA9FB8A9AE3FDCE7071	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	Villa, Andrea;Macaluso, Loredana;Mörs, Thomas	Villa, Andrea, Macaluso, Loredana, Mörs, Thomas (2024): Miocene and Pliocene amphibians from Hambach (Germany): New evidence for a late Neogene refuge in northwestern Europe. Palaeontologia Electronica (a 3) 27 (1): 1-56, DOI: 10.26879/1323, URL: http://dx.doi.org/10.26879/1323
