''Rhigosaurus glacialis'' is a species of therocephalian therapsid. Its fossilized remains have been found in the Fremouw Formation of Antarctica and Australia. Part of a juvenile skull was found near

Mount Kenyon The Cumulus Hills () are several groups of largely barren hills in Antarctica. Divided by the Logie Glacier, they are bounded by Shackleton Glacier on the west, McGregor Glacier on the north and Zaneveld Glacier on the south. Discovery and ...

, Antarctica. The

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

of the partial skull shows evidence of promiment upper and lower canine teeth. The genus name ''Rhigosaurus'' comes from the Greek , meaning cold, and , meaning lizard or reptile. The name was coined by Edwin Harris Colbert and James William Kitching, who described the species in 1981 based on a fossil found in 1970-1971. They described it as robust and small in size. The fossil skull was long and across at the widest point. Modern paleontologists such as

Christian Sidor Christian Alfred Sidor is an American vertebrate paleontologist. He is currently a Professor in the Department of Biology, University of Washington in Seattle, as well as Curator of Vertebrate Paleontology and Associate Director for Research and C ...

consider the species a

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium,'' it may be impossible to determine whether a ...

. Sidor describes it as an "indeterminate juvenile baurioid" and suggests that the name ''Rhigosaurus'' be discontinued.

References

Therocephalia genera Baurioidea Triassic synapsids Extinct animals of Antarctica Triassic Antarctica Fossils of Antarctica Fossil taxa described in 1981 {{Paleo-therapsid-stub