The evolutionary origin of aniliids remains obscure. Fossil vertebrae ascribed to this family have been recovered from Cretaceous deposits in Wyoming and New Mexico. These fossils look superficially like the vertebrae of living aniliids except for two features of the neural arch that are more similar to those found in living scolecophidian snakes. Much of the older literature uses the term "aniliid" to refer to all basal alethinophidian lineages. Hence, it is unclear whether many of these data actually apply to Aniliidae sensu stricto. Recent phylogenetic analyses have produced conflicting results with respect to the relationships of aniliids, although most analyses place aniliids closest to the anomochilid-uropeltid-cylindrophiid lineages. Aniliids are therefore one of a group of relict, basal alethinophidian taxa.
The family contains a single species that has been divided into two subspecies based on ventral counts and the relative lengths of black and red rings on the body. The northern (Venezuelan) subspecies A. scytale phelpsorum is purported to have fewer than 225 ventrals and have black bands longer than the red bands, whereas the subspecies occupying the remainder of the family's range, A. scytale scytale, has more than 225 ven trals and has black bands shorter than the red bands. Specimens with characteristics of both subspecies have been found in northern Brazil and French Guiana. No subfamilies are recognized.
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