''Sphodrosaurus'' is an extinct

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of basal

archosauriform Archosauriformes (Greek for 'ruling lizards', and Latin for 'form') is a clade of diapsid reptiles encompassing archosaurs and some of their close relatives. It was defined by Jacques Gauthier (1994) as the clade stemming from the last common anc ...

reptiles from the

Late Triassic The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch a ...

-aged

New Oxford Formation The New Oxford Formation is a mapped bedrock unit consisting primarily of sandstones, conglomerates, and shales. The New Oxford Formation was first described in Adams County, Pennsylvania in 1929, and over the following decade was mapped in adjace ...

(not the Brunswick Formation as initially suggested) of

Pennsylvania Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...

. The type species is ''S. pennsylvanicus'', described by

Edwin Colbert Edwin Harris "Ned" Colbert (September 28, 1905 – November 15, 2001)O'Connor, Anahad ''The New York Times'', November 25, 2001. was a distinguished American vertebrate paleontologist and prolific researcher and author. Born in Clarinda, Iowa, he ...

in 1960. Colbert, E. H. (1960). A New Triassic Procolophonid from Pennsylvania. ''American Museum Novitates'' 2022:1-19 The holotype ( NMN, Franklin and Marshall College 2321; the cast is listed under AMNH 7601) consists of a partial skeleton including the back of the skull, the vertebral column, all of the ribs, all of the hindlimbs and part of the upper forelimbs; ''Sphodrosaurus'' was originally believed to have been a member of the

Procolophonidae Procolophonidae is an extinct family (biology), family of small, lizard-like parareptiles known from the Late Permian to Late Triassic that were distributed across Pangaea, having been reported from Europe, North America, China, South Africa, Sou ...

while more recently ''Sphodrosaurus'' was believed to be a basal member of the

Diapsida Diapsids ("two arches") are a clade of sauropsids, distinguished from more primitive eureptiles by the presence of two holes, known as temporal fenestrae, in each side of their skulls. The earliest traditionally identified diapsids, the araeosc ...

by most authors starting with Sues ''et al.'' (1993), or a member of the

Rhynchosauria Rhynchosaurs are a group of extinct herbivorous Triassic archosauromorph reptiles, belonging to the order Rhynchosauria. Members of the group are distinguished by their triangular skulls and elongated, beak like premaxillary bones. Rhynchosaurs ...

(Baird, 1986). In 2022, Ezcurra & Sues redescribed the holotype in detail and placed it in a phylogenetic analysis with other Triassic diapsid reptiles, where it was found as the basalmost doswellid.

References

Prehistoric reptile genera Late Triassic extinctions Taxa named by Edwin H. Colbert Fossil taxa described in 1960 {{paleo-reptile-stub