Roots of the European Cenozoic ecosystems: lizards from the Paleocene (MP 5) of Walbeck in Germany

We studied at least part of Kuhn's original material of lizards from the Paleocene (similar to MP 5) of the Walbeck locality in Germany. The collection was considered to be lost but is consistently discussed in the literature due to its importance. We restudied the type material of aff. Parasauromalus paleocenicus and aff. Glyptosaurus walbeckensis described by Kuhn in 1940. The former was originally allocated to Iguania, the latter to Anguimorpha, though later on these identifications were questioned by several authors. We show such a classification of both cannot be upheld. P. paleocenicus resembles the morphology of lacertids showing their presence in Europe already around MP 5. We consider the name P. paleocenicus as a nomen dubium. The material of aff. G. walbeckensis was later suggested to belong to Lacertidae and also considered as a potential amphisbaenian. Although it differs from modern amphisbaenians, it shares features with one supposed polyodontobaenid - Camptognathosaurus parisiensis. The Walbeck form is identical to this species. Since the Walbeck taxon was described in 1940, the principle of priority makes Camptognathosaurus parisiensis a junior synonym of the species erected by Kuhn. We propose a new combined name for this form, Camptognathosaurus walbeckensis comb. nov. The specimen figured by Kuhn is currently lost, thus we designate a neotype from Walbeck. However, this taxon differs significantly from Polyodontobaena and new data doubt the attribution of Camptognathosaurus to Amphisbaenia. This taxon is tentatively assigned here to Lacertidae, as further confirmed by phylogenetic analyses. Material of Scincoidea is also described.