Primitive Snakes

Abstract

There seems no doubt that the snakes arose from burrowing or aquatic lizard-like ancestors, although the fossil evidence is thin and does not extend earlier than the lower Cretaceous. The early snakes were rather short, thick-bodied reptiles of comparatively large size with a mixture of lizard and snake characters. Among the many lizard families there is no certainty which is the most closely related to the snakes. The varanid and lanthanotid lizards have both been considered as candidates to share snake ancestry, although neither group has leg-less forms and any resemblances with the snakes may be fortuitous. On the other hand the various snake-like lizards, which at first sight would seem to be better qualified, are probably instances of convergence and have no close relationship with the snakes.