TY - JOUR
AU - SCOTT,, DIANE
AB - Abstract The cranial anatomy of the Early Permian sphenacodontid synapsid Secodontosaurus is redescribed. There is no evidence for recognition of more than one species of Secodontosaurus, and S. willistoni is declared a junior subjective synonym of S. obtusidens. Numerous derived characters (autapomorphies), mainly related to the unusually slender and slightly elongated skull, distinguish Secodontosaurus. The cranial specializations are interpreted as an adaptation toward a feeding strategy which involved preying upon small tetrapods that attempted to avoid capture by hiding in crevices and burrows. A cladistic analysis supports the following hypotheses of relationships: (a) the Sphenacodontidae is the nearest sister taxon of Therapsida; (b) Secodontosaurus, Sphenacodon, Ctenospondylus and Dimetrodon share a more recent common ancestor with one another than any of them do with Haptodus, and (c) Secodontosaurus shares a more recent common ancestor with Dimetrodon than with either Sphenacodon or Ctenospondylus. The latter hypothesis suggests that the sphenacodont subfamily ‘Sphenacodontinae’ is paraphyletic and, therefore, invalid. Secodontosaurus, Synapsida, Sphenacodontidae, mammal-like reptile, Palaeozoic, osteology, phytogeny REFERENCES. AX , P. 1987 . The Phylogenetic System: The Systematization of Living Organisms on the Basis of Their Phylogenesis . Toronto : John Wiley and Sons . Google Scholar Google Preview OpenURL Placeholder Text WorldCat COPAC BERMAN , D. S. & REISZ , R. R. 1982 . 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TI - The cranial anatomy and relationships of Secodontosaurus, an unusual mammal-like reptile (Synapsida: Sphenacodontidae) from the early Permian of Texas
JF - Zoological Journal of the Linnean Society
DO - 10.1111/j.1096-3642.1992.tb00920.x
DA - 1992-02-01
UR - https://www.deepdyve.com/lp/oxford-university-press/the-cranial-anatomy-and-relationships-of-secodontosaurus-an-unusual-6stkf0zKbz
SP - 127
EP - 184
VL - 104
IS - 2
DP - DeepDyve
ER -