Palaeogene records of Glyptosauridae (Squamata: Anguimorpha) from Kazakhstan and Mongolia
摘要
Glyptosauridae (Squamata, Anguimorpha), an extinct group of heavily armoured lizards, are well recorded from Europe and North America, but extremely poorly represented in Asia. Here selected Asian records of Glyptosauridae are reviewed. Records from Kazakhstan, all from the upper Eocene Aksyir Formation, are described for the first time. The occurrence of Glyptosauridae in the Oligocene of Kazakhstan is not confirmed. A maxilla and dentary of Glyptosauridae from the Khoer Dzan locality of Mongolia are described and discussed. The Kazakhstan and Mongolian glyptosaurids are more similar to Helodermoides tuberculatus from North America than they are to European species of Placosaurus. This similarity supports the North American origin for the Asian glyptosaurids, which were derived from an Eocene member of a clade closely related to Helodermoides. The presence of ‘Melanosaurinae’ in Mongolia is not confirmed. This study provides updated information on the stratigraphical and geographical distribution of Glyptosauridae in Asia.