The easternmost record of the largest anguine lizard that has ever lived – Pseudopus pannonicus (Squamata, Anguidae): new fossils from the late Neogene of Eastern Europe

Abstract

We here report on new material of Pseudopus pannonicus, the iconic and largest-known representative of the lizard clade Anguinae, from several late Neogene localities across Moldova, Ukraine, and regions of the North Caucasus – the last representing the easternmost known occurrence of this extinct species. Today, Pseudopus apodus, the last extant Pseudopus representative, is found in a variety of habitats ranging from South-East Europe to Central Asia. In the late Cenozoic of Europe, however, several extinct species of Pseudopus existed. Among them, interestingly, P. pannonicus displayed the largest spatiotemporal range of the genus, occurring from Spain to the North Caucasus and known from the Late Miocene to the Early Pleistocene. Although it has been reported in a plethora of European localities, P. pannonicus is a taxon “with several questionings related to its few diagnostic features vs. numerous features shared with P. apodus”. The elements described here exhibit some variability, but their overall morphology undoubtedly resembles that of previously described material of P. pannonicus. The lacrimal from Tatareshty, moreover, represents the first fossil lacrimal reported for P. pannonicus. Besides, the fairly complete maxilla with a length of almost 3.7 cm is the largest maxilla ever reported for this taxon, expanding our knowledge of its gigantism. In addition, several features are described and discussed regarding their diagnostic relevance for P. pannonicus. The relationship between body size and some of these features was tested statistically. Consequently, two cranial characters and one vertebral feature peculiar to P. pannonicus were retained in the diagnosis of the species.