First remains of diplocynodon cf. Ratelii from the early miocene sites of ahníkov (most basin, czech republic)

Abstract

Fossil crocodylians from the early Miocene (Eggenburgian, MN3a) sites of Ahníkov (Most Basin, Czech Republic) are described in this paper. The new material presented here includes over 200 remains (bones, teeth and osteoderms), and therefore constitutes the largest crocodylian sample known from the fossil record of the Czech Republic. Assignment of the specimens to the fossil alligatoroid taxon Diplocynodon cf. ratelii Pomel, 1847 (family Diplocynodontidae) is justified by the presence of several cranial and postcranial features. In the Czech Republic, this species has been previously reported only from the Tušimice site (MN3, Most Basin, Ohře/Eger Graben). The majority of the material reported from Ahníkov is composed of disarticulated juvenile individuals. Both sites are most likely attributable to the specific environment of swampy areas, where crocodile hatchlings would hide from predators. The presence of the genus Diplocynodon supports the assumption of rather warm climatic conditions in Central Europe during the early to middle Miocene, as well as a swampy depositional environment previously inferred for Ahníkov. However, some squamate taxa suggest the existence of additional, surrounding palaeoenvironment characterised by a more open landscape with slightly drier conditions.