Anguinae is a subfamily of

legless lizard Legless lizard may refer to any of several groups of lizards that have independently lost limbs or reduced them to the point of being of no use in locomotion.Pough ''et al.'' 1992. Herpetology: Third Edition. Pearson Prentice Hall:Pearson Education ...

s in the family

Anguidae Anguidae refers to a large and diverse family of lizards native to the Northern Hemisphere. Common characteristics of this group include a reduced supratemporal arch, striations on the medial faces of tooth crowns, osteoderms, and a lateral fold ...

, commonly called glass lizards, glass snakes or

slow worm The slow worm (''Anguis fragilis'') is a reptile native to western Eurasia. It is also called a deaf adder, a slowworm, a blindworm, or regionally, a long-cripple and hazelworm. These legless lizards are also sometimes called common slowworms. ...

s. The first two names come from the fact their tails easily break or snap off. Members of Anguinae are native to North America, Europe, Asia, and North Africa.

Evolution

They first appeared in Europe during the early

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

, approximately 48.6 million years ago, originating from North American ancestors that crossed over from Greenland via the

Thule Land Bridge The Thule Land Bridge (also called the Thulean North Atlantic Bridge) was a land bridge, now submerged beneath the Atlantic Ocean, that connected the British Isles to central Greenland. The land bridge appeared during the Late Paleocene and disap ...

and spread toward Asia sometime after the drying of the

Turgai Strait The Turgai Sea, also known as the Turgay Sea, Turgai Strait, Obik Sea, Ural Sea or West Siberian Sea, was a large shallow body of salt water (an epicontinental or epeiric sea) during the Mesozoic through Cenozoic Eras. It extended north of the pres ...

at the beginning of the

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but ...

, and then across the

Bering Land Bridge Beringia is defined today as the land and maritime area bounded on the west by the Lena River in Russia; on the east by the Mackenzie River in Canada; on the north by 72 degrees north latitude in the Chukchi Sea; and on the south by the tip o ...

to North America during the

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" ...

Description

Very

vestigial Vestigiality is the retention, during the process of evolution, of genetically determined structures or attributes that have lost some or all of the ancestral function in a given species. Assessment of the vestigiality must generally rely on co ...

hindlegs are present in '' Hyalosaurus'' and ''

Pseudopus ''Pseudopus'' is a genus of anguid lizards that are native to Eurasia. One extant species remains, the sheltopusik, with four fossil species. They are the most robust members of subfamily Anguinae. The oldest fossils of the group date to the Ear ...

'', but are entirely absent in the other

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial ...

.Lavin, & Girman, D. J. (2019). Phylogenetic relationships and divergence dating in the Glass Lizards (Anguinae). Molecular Phylogenetics and Evolution., 133, 128–140. Members of the group largely feed on insects and other invertebrates. The largest living species, the

Sheltopusik The sheltopusik (''Pseudopus apodus''), also commonly called Pallas's glass lizard the European legless lizard, or the European glass lizard, is a species of large glass lizard found from Southern Europe to Central Asia. Etymology ''Pseudo ...

(''Pseudopus apodus''), can reach lengths of .

Taxonomy

The subfamily contains the following genera: * ''

Dopasia ''Dopasia'' is a genus of lizards in the family Anguidae. The genus contains seven species, which are native to Asia. They are most closely related to the North American '' Ophisaurus'', and are sometimes considered part of that genus. Species T ...

'' (7 species), native to eastern Asia * '' Hyalosaurus'' (1 species), native to North Africa * ''

Ophisaurus ''Ophisaurus'' (from the Greek 'snake-lizard') is a genus of superficially snake-like lizards in the family Anguidae. Known as joint snakes, glass snakes, or glass lizards, they are so-named because their tails are easily broken; like many liz ...

'' (6 species), native to eastern North America * ''

'' (1 extant species, the

), native to Europe and Asia * ''

Anguis SlowwormsThe "slow-" in slowworm is distinct from the English adjective ''slow'' ("not fast"); the word comes from Old English ''slāwyrm'', where ''slā-'' means "slowworm" and ''wyrm'' means "serpent, reptile". () (also called blindworms and ha ...

'' - slowworms (5 species), native to Europe and Western Asia Relationships after Lavin & Girman, 2019:

References

Anguids {{Anguidae-stub