Scientific name Amphisbaenidae | Clade Amphisbaenia Phylum Chordata Rank Family | |
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Similar Amphisbaena, Reptile, Amphisbaenia, Scaled reptiles, Amphisbaena alba | ||
The Amphisbaenidae, common name worm lizards, are a family of amphisbaenians, a group of limbless vertebrates.
Contents
Geographic range
Amphisbaenids occur in South America, some Caribbean islands, and in Sub-Saharan Africa.
Taxonomy
One deep-branching and somewhat aberrant genus, Blanus, is native to Europe, and may represent a distinct family. More recent sources indeed place it in the family Blanidae.
Description
Members of the family are limbless, burrowing, lizards with carnivorous diets. As in other amphisbaenians, the body bears rings of scales, which gives amphisbaenids a worm-like appearance. The heads are massively constructed and used for burrowing, with powerful jaws and large, recurved teeth used for seizing prey. Some species have spade-like heads, while others have a narrow keel on their heads, and still others have a rounded skull. The eyes are highly reduced, while the ear bone, or stapes in the middle ear, is large and massive. Together with another bone, the extracollumella, the stapes detects vibrations caused by prey items, allowing amphisbaenids to hunt for invertebrates underground. In this respect there apparently is evolution convergent to the burrowing mammalian family Chrysochloridae, in which the malleus in the middle ear is greatly enlarged.
Genera
Over 120 species are in the family, grouped into 17 genera:
Fossil record
A number of extant and extinct taxa are known from the fossil record:
