''Atokasaurus'' is an extinct

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 ...

scincomorph Scincomorpha is an infraorder and clade of lizards including skinks (Scincidae) and their close relatives. These include the living families Cordylidae (girdled lizards), Gerrhosauridae (plated lizards), and Xantusiidae (night lizards), as wel ...

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

from the

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

of Oklahoma. The type and only species is ''Atokasaurus metarsiodon'', named in 2002 on the basis of a single isolated lower jaw bone found within the

Antlers Formation The Antlers Formation is a stratum which ranges from Arkansas through southern Oklahoma into northeastern Texas. The stratum is thick consisting of silty to sandy mudstone and fine to coarse grained sandstone that is poorly to moderately sorte ...

Atoka County Atoka County is a county located in the U.S. state of Oklahoma. As of the 2010 census, the population was 14,007. Its county seat is Atoka. The county was formed before statehood from Choctaw Lands, and its name honors a Choctaw Chief named ...

. It is similar in appearance to extinct lizards in the family

Paramacellodidae Paramacellodidae is an extinct family of lizards that first appeared in the Middle Jurassic around 170 million years ago (Ma) and became extinct at the end of the Cretaceous around 66 Ma. It was one of the earliest groups of lizards to have under ...

and may itself be a paramacellodid, although the

phylogenetic 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 ...

relationships of the group are uncertain. ''Atokasaurus'' differs from other paramacellodids in having teeth in the lower jaw with enlarged bases and an S-shaped profile when viewed edge-on.

References

Early Cretaceous reptiles of North America Cretaceous lizards Fossil taxa described in 2002 {{paleo-lizard-stub