Did the snake used to have legs?
Snakes evolved from legged ancestors, yes. Fossil snakes have been found that still had tiny rear legs, but as yet one has not been found with any trace of front legs – snake skeletons are delicate and rarely fossilise. Some snakes – including, but not limited to, pythons and boas – still have a pelvic girdle, attached to two small claws, called spurs, on either side of the cloaca. These are used in courtship, which may be why they have been retained. In response to BWANA’s answer, I’d like to point out that snakes are not the only reptiles to lack eyelids – chameleons and certain gecko species do not have eyelids, either. There are various characteristics that make a snake a snake, including the structure of the skull, the arrangement of the internal organs, and the lack of external ears.
