Amphibia and Squamata

Abstract

The Pliocene of Laetoli (Tanzania) has produced a taxonomically unbalanced fauna of amphibians and squamate reptiles. Amphibians are represented by only two specimens belonging to indeterminate anurans. Similarly, lizards are comprised of two specimens that are referred to an indeterminate acrodontan and an indeterminate scincomorphan. Snakes are more numerous (more than 150 specimens) and taxonomically diverse. They include a boid (Python sebae or P. natalensis), at least three colubrids (cf. Thelotornis, cf. Rhamphiophis, one indeterminate colubrid, and another indeterminate taxon that might be a modern specimen), an elapid (Naja robusta), a possible distinct elapid, and a viperid (Bitis olduvaiensis or a new species of Bitis). The latter taxon represents the most common snake. The paleoecological implications of the fauna are not readily apparent because the most useful indicator taxa are distributed in different beds. Based on the entire fauna it may be concluded that the Laetoli area was neither a desert nor covered by forest. Bodies of water were periodically present, at least during the period of deposition of the Upper Laetolil Beds. An unusual feature of the Laetoli snake community, but similar to a few other Neogene faunas from sub-Saharan Africa, is the fact that colubrids are not the dominant taxon.