New amphisbaenian lizards from the Early Paleogene of Europe and their implications for the early evolution of modern amphisbaenians
Scientific Heritage Survey, Royal Belgian Institute of Natural Sciences, rue Vautier 29, B-1000 Brussels, Belgium. E-mail: annelise.folie@naturalsciences.be
O.D. Earth and History of Life, Royal Belgian Institute of Natural Sciences, rue Vautier 29, B-1000 Brussels, Belgium. E-mail: richardsmithpal@hotmail.com
O.D. Earth and History of Life, Royal Belgian Institute of Natural Sciences, rue Vautier 29, B-1000 Brussels, Belgium. E-mail: thierry.smith@naturalsciences.be
Abstract
Three new amphisbaenian lizard taxa are described from the Early Paleogene of Western Europe. Two new basal forms, Polyodontobaena belgica gen. et sp. nov. from the Early Paleocene of Hainin (Belgium) and Camptognathosaurus parisiensis gen. et sp. nov. from the Late Paleocene of Rivecourt-Patit Pâtis and Cernay-lès-Reims (France), are characterised by a dentary lacking a strong angle at the symphysis and bearing 10 to 12 massively built and conical teeth. These two taxa form the new family Polyodontobaenidae. A third new amphisbaenian, Blanosaurus primeocaenus gen. et sp. nov., is also described from the Early Eocene of Dormaal (Belgium), Condé-en-Brie and Prémontré (France) and represents the oldest modern amphisbaenian lizard of Europe, tentatively assigned to Blanidae. It is characterised by a reduction of tooth number and by the presence of a strong angle at the symphysis. Palaeobiogeographic considerations suggest a first hypothesis that the Eocene forms would have evolved from the Paleocene species.The second hypothesis would be that as for the lizard Scincoideus haininensis, primitive amphisbaenians were present in Europe from the Paleocene,whereas beginning in the Early Eocene only modern forms with typical reduced dentition (fewer than 10 teeth) are present. The origin of these modern forms is very likely related with the dispersal of the first modern mammals.