Sphodrosaurus is an extinct genus of basal archosauriform reptiles from the Late Triassic-aged New Oxford Formation (not the Brunswick Formation as initially suggested) of Pennsylvania. The type species is S. pennsylvanicus, described by Edwin Colbert 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 while more recently Sphodrosaurus was believed to be a basal member of the Diapsida by most authors starting with Sues et al. (1993),Sues, H-D., Baird, D., and Olsen, P.E. (1993). Redescription of Sphodrosaurus pennsylvanicus Colbert, 1960 (Reptilia) and a Reassessment of its Affinities. Annals of Carnegie Museum 62(3):245-253 or a member of the Rhynchosauria (Baird, 1986Baird, D. (1986). Some Upper Triassic reptiles, footprints and an amphibian from New Jersey. The Mosasaur 3:125-153). 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.
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