After spurs or dew claws are the rudimentary remains of hind limbs , which in some taxa of snakes exist. These are parts of the basin that are considered to be an indication of the evolutionary descent of the snakes from four-legged reptiles . Accordingly, they are mainly found at very basal taxa, such as the blind snakes , rolling snakes , Wühlschlangen , pipesnakes and the boas and pythons . Especially in the latter two families, the dewclaws sometimes protrude from the body on both sides of the anus .
Anal spurs serve in some species to hold the partner in place during the reproductive act.
- Roland Bauchot (Ed.): Snakes. Bechtermünz Verlag, Augsburg 1998, ISBN 3-8289-1501-9 .