Bipedidae is a

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

amphisbaenians Amphisbaenia (called amphisbaenians or worm lizards) is a group of usually legless squamates, comprising over 200 extant species. Amphisbaenians are characterized by their long bodies, the reduction or loss of the limbs, and rudimentary eyes. As ...

that includes the extant

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

'' Bipes'' represented by three

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

from

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

and the southern coast of

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

and the extinct genus ''

Anniealexandria ''Anniealexandria'' is an extinct genus of amphisbaenian lizard known by the type species ''Anniealexandria gansi'' from the earliest Eocene of Wyoming. ''Anniealexandria'' is the only known member of the family Bipedidae in the fossil record, w ...

'' represented by one species that lived in what is now

Wyoming Wyoming () is a U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the south ...

during the earliest Eocene around 55 million years ago.

Phylogenetic analysis In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

indicates that Bipedidae is most closely related to the family

Blanidae ''Blanus'' is a genus of amphisbaenians found in the Mediterranean region of Europe and North Africa. Like other amphisbaenians, ''Blanus'' species are specialized for a subterranean existence, with long, slender bodies, reduced limbs, and rudim ...

, which includes the living genus ''

Blanus ''Blanus'' is a genus of amphisbaenians found in the Mediterranean region of Europe and North Africa. Like other amphisbaenians, ''Blanus'' species are specialized for a subterranean existence, with long, slender bodies, reduced limbs, and rudim ...

''. Bipedidae are very small usually ranging from 120 to 240 mm, and have large mole-like limbs that each include five claws. They have a short tail that does not regenerate if lost. They use their blunt head for burrowing by ramming it into the soil, and usually prey on arthropods.

References

Amphisbaenians Lizard families Taxa named by Edward Harrison Taylor Extant Eocene first appearances {{lizard-stub