Regisaurus

Regisaurus Temporal range: Late Permian–Early Triassic PreꞒ Ꞓ O S D C P T J K Pg N
Restoration of R. jacobi
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Synapsida
Order:	Therapsida
Suborder:	Therocephalia
Family:	Regisauridae
Genus:	Regisaurus
Species
R. jacobi Mendrez, 1972

Regisaurus("rex's lizard", named after its discoverer Francis Rex Parrington) is an extinct genus of small carnivorous theriodont from the Lystrosaurus Assemblage Zone of South Africa.^[1]

Description

It was around 30 centimetres (12 in) in length, with long limbs and relatively small teeth. Like Urumchia, it had vomer bones, but they are not narrow at the end like in Urumchia. Also, unusually for a baurioid it has six incisor teeth.

Discovery and species

Regisaurus was discovered in 1964 by Francis Rex Parrington and it was named in 1972 by C. H. Mendrez. Two species are known, the type species R. jacobi and the possible species R.sp. R. jacobi is known from the holotype FRP 1964/27 which consists of the skull, the posterior half of left dentary, the ilium, both femora, both tibias, both fibulas, the calcaneum and astragalus of the left side,the left scapulo-coracoid, several isolated vertebrae, some ribs and unidentifiable foot bones.^[2] Its relative R. sp is known from the holotype T837 which consists of a fragmentary skull and a nearby complete skeleton.^[3][4]

Classification

Below is a cladogram modified from analysis published by Adam K. Huttenlocker in 2014.

Palaeobiology

It was probably fairly active, and ate insects and small vertebrates. The fossils suggest that it was an arboreal/terrestrial/burrowing carnivore, which was nocturnal and possibly hunted in packs.

See also

• List of therapsids

References

1. ↑ C. H. Mendrez (1972). "On the skull of Regisaurus jacobi, a new genus and species of Bauriamorpha Watson and Romer 1956 (=Scaloposauria Boonstra 1953), from the Lystrosaurus-zone of South Africa". In K.A. Joysey, T.S. Kemp. Studies in Vertebrate Evolution. Edinburgh: Oliver & Boyd. pp. 191–212. ISBN 9780050021316. 
2. ↑ http://www.paleofile.com/Theriodontia/Regisaurus.asp
3. ↑ Kemp, T.S. (1986). "The skeleton of a baurioid therocephalian therapsid from the Lower Triassic (Lystrosaurus Zone) of South Africa" (PDF). Journal of Vertebrate Paleontology 6 (3): 215–232. doi:10.1080/02724634.1986.10011617. JSTOR 4523096. Retrieved 26 March 2011. 
4. ↑ http://www.paleofile.com/Theriodontia/Regisaurussp.asp