Palaeoproteus miocenicus

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.

Figure 5

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.

Material. Hambach 6 C: one humerus (IPB-HaH 2390).