Introduction

Anguinomorph lizards have attracted the attention of various workers for several reasons. They form a lacertilian infraorder well defined by the subdivision of their tongue into a retractile fore-portion and a broad, elastic hind-portion. The long, independent evolutionary history is documented by a rich fossil record (Hoffstetter, 1962 a). The lizards referred to the Anguinomorpha are subdivided into two suprafamilies, the Anguinoidea and the Platynota. The Anguinoidea comprise three families, the Anguidae, Xenosauridae and Anniellidae. The Platynota comprise seven families, the Helodermatidae, Parasaniwidae, Lanthanotidae, Dolichosauridae, Aigialosauridae, Mosasauridae and Varanidae. The Anguinomorpha exhibit a wide range of adaptation from the burrowing Anniellidae to the Dolichosauridae, Aigialosauridae and Mosasauridae, inhabitants of the Cretaceous seas. Since the days of Nopsca (1903,1908,1923), Janesch (1906) and Fejervary (1918) they stand as ancestors of snakes, a view which was accepted by Camp (1923) and McDowell and Bogert (1954, see also McDowell, 1972).