Chelotriton sp.

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 : 13

? Chelotriton sp.

Figure 9

Material. Hambach 6C: two humeri (IPB-HaH 2389, IPB-HaH 2393).

Description. These humeri are moderately large and well ossified. IPB-HaH 2389 ( Figure 9 A-B) preserves only the proximal half, which is about 9.5 mm long. The humerus head is rather flat proximally. On the ventral side, the ventral crest of the humerus is well developed and robust. It has an almost horizontal distal margin and a rather steep proximal margin. The crest does not bear a distinct sulcus ventrally. On the other side of the bone, the dorsal crest of the humerus is present as a short and pointed process. IPB-HaH 2393 ( Figure 9 C-D), on the other hand, is represented only by the distal epiphysis, which is about 6.5 mm in length. It has deep cubital ventral and olecranon fossae. The distal portion of the epiphysis was not coossified with the rest of it.

Remarks. These humeri are tentatively assigned to Chelotriton because of the size and the strong ossification. Proteids and likely batrachosauroidids have poorly ossified long bones, and the two specimens are larger and more ossified than bones of other salamandrids identified in Hambach and not as large as those of adult cryptobranchids.

Figures

FIGURE 9. Limb bones of possible Chelotriton sp. from Hambach: left humerus (IPB-HaH 2389) in anterior (A) and posterior (B) views; right humerus (IPB-HaH 2393) in ventral (C) and dorsal (D) views. Scale bars equal 1 mm. Abbreviations: cvf, cubital ventral fossa; dc, dorsal crest of the humerus; h, humeral head; of, olecranon fossa; vc, ventral crest of the humerus.