The Amerophidia, also known as amerophidian snakes, are a clade of

snake Snakes are elongated limbless reptiles of the suborder Serpentes (). Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group. Many species of snakes have s ...

s that contains two families: Aniliidae (containing a single species, '' Anilius scytale'', the American red pipe snake or false coral snake) and the boa-like

Tropidophiidae The Tropidophiidae, common name dwarf boas or thunder snakes, are a family of nonvenomous snakes found from Mexico and the West Indies south to southeastern Brazil. These are small to medium-sized fossorial snakes, some with beautiful and strikin ...

(containing two genera, '' Trachyboa'' (with two species) and ''

Tropidophis ''Tropidophis'', common name Caribbean dwarf boas, wood snakes or West Indian wood snakes,Hampton Wildman Parker, Parker HW, species:Alice Georgie Cruickshank Grandison, Grandison AGC (1977). ''Snakes — a Natural History''. Second Edition. Lond ...

'' (with either 17 or 33, depending on the authority)). The sister-group relationship between these two families is surprising and unintuitive when only morphology is considered, because Aniliidae more closely resemble the Asian pipe snakes in the families

Cylindrophiidae The Cylindrophiidae are a monotypic family of secretive, semifossorial, non-venomous snakes containing the genus ''Cylindrophis'' found in southeastern Asia. These are burrowing snakes and most have a banded pattern on the belly. Currently, 14 sp ...

and

Anomochilidae Anomochilidae is a Family (biology), family of snakes with one genus, ''Anomochilus'', containing three species of snake. Members of the genus are known as anomochilids, or by the common name, common names dwarf pipesnakes, lesser pipesnakes, ...

, whereas Tropidophiidae more closely resemble constricting, macrostomatan snakes such as

Boidae The Boidae, commonly known as boas or boids, are a family of nonvenomous snakes primarily found in the Americas, as well as Africa, Europe, Asia, and some Pacific islands. Boas include some of the world's largest snakes, with the green anaconda ...

and

Pythonidae The Pythonidae, commonly known as pythons, are a Family (biology), family of Venomous snake, nonvenomous snakes found in Africa, Asia, and Australia. Among its members are some of the largest snakes in the world. Ten Genus, genera and 39 specie ...

. However, every major phylogenetic analysis since 2007 has found support for the idea that these two families are one another's closest relatives, despite having last shared a common ancestor about 91 MYA I: 77-104 The oldest fossil member of this family is the extinct '' Australophis'' from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

of Argentina.

References

Alethinophidia Extant Santonian first appearances {{Alethinophidia-stub