Palaeobatrachidae, Cope, 1865

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), pp. 1-56 : 27

? Palaeobatrachidae indet.

Figure 18

Material. Hambach 6C: one maxilla (IPB-HaH 2279).

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.

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.

Figures

FIGURE 18. Possible Palaeobatrachidae indet. from Hambach: fragment of maxilla (IPB-HaH 2279) in medial (A), lateral (B), dorsal (C) and ventral (D) views. Scale bar equals 1 mm.