Revision of the anguine lizard Pseudopus laurillardi (Squamata, Anguidae) from the Miocene of Europe, with comments on paleoecology

A revision of the Early-Middle Miocene anguine, Pseudopus laurillardi (Lartet, 1851), is presented based on a detailed anatomical analysis of one newly discovered articulated specimen and numerous disarticulated cranial and postcranial elements from several localities in Germany, as well as on the restudy of the original skeletal material of Lartet. the articulated specimen represents the first record of an articulated anguine from the Neogene. We demonstrate that the contemporaneous anguine Propseudopus fraasii (= Pseudopus fraasi, Pseudopus moguntinus or Ophisaurus moguntinus) from Germany and elsewhere in Europe represents a junior synonym of P. laurillardi. Three species of Pseudopus can by discriminated in the Cenozoic of Eurasia: P. laurillardi (Early-Middle Miocene of Europe), P. pannonicus (Late Miocene-Middle Pleistocene of central and eastern Europe) and P. apodus (Late Pleistocene-Recent, from Eastern Europe to central Asia). Eleven morphological characters of the skull have been identified that distinguish Pseudopus laurillardi from P. pannonicus and P. apodus. Four of these characters regard the frontal and parietal bones, whereas all other characters regard the dentary and dentition. the genus Pseudopus represents the largest and most robust taxon in the subfamily Anguinae and first occurs in central Europe at the beginning of MN 4 (~18.5 Ma). in contrast to the extant species, P. apodus, the fossils P. laurillardi and P. pannonicus had a greater ecological plasticity and lived in various types of environments. the fossil remains of these taxa are most frequently found in localities characterized by sub-humid to humid climate, which may indicate that their preferential habitats include forested environments.