Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

Diademodon tetragonus Seeley, 1894 (Therapsida: Cynodontia) in the Triassic of South America and Its Biostratigraphic Implications

Agustín G. Martinelli, Marcelo de la Fuente and Fernando Abdala
Journal of Vertebrate Paleontology
Vol. 29, No. 3 (Sep. 12, 2009), pp. 852-862
Stable URL: http://www.jstor.org/stable/20627095
Page Count: 11
  • Subscribe ($19.50)
  • Cite this Item
Diademodon tetragonus Seeley, 1894 (Therapsida: Cynodontia) in the Triassic of South America and Its Biostratigraphic Implications
Preview not available

Abstract

We report for the first time the presence of the cynodont Diademodon tetragonus Seeley, 1894 in the South American Triassic. The specimen, represented by a fragmented skull and lower jaws, was found in levels of the Río Seco de la Quebrada Formation (Puesto Viejo Group), Mendoza Province, Argentina. It is assigned to D. tetragonus based on its overall skull shape (narrow and elongated snout with a concave outline in dorsal view), the morphology of the jugal that forms most of the dorsoventral depth of the zygoma and shows a well-excavated external auditory meatus, and a postcanine series including circular outlined anterior teeth, ovoid gomphodont teeth in the middle, and posterior sectorial teeth. The association of this taxon with the cynodonts Cynognathus crateronotus and Pascualgnathus polanskii, along with comparisons to African Triassic assemblages, suggest an Early to Late Anisian age for the Río Seco de la Quebrada Formation. These levels are most likely correlated to the subzones B and C of the South African Cynognathus Assemblage Zone, where both Cynognathus and Diademodon are known. This discovery represents the fourth report of shared cynodont genera between allegedly Lower to Middle Triassic African and South American terrestrial faunas.

Page Thumbnails

  • Thumbnail: Page 
852
    852
  • Thumbnail: Page 
853
    853
  • Thumbnail: Page 
854
    854
  • Thumbnail: Page 
855
    855
  • Thumbnail: Page 
856
    856
  • Thumbnail: Page 
857
    857
  • Thumbnail: Page 
858
    858
  • Thumbnail: Page 
859
    859
  • Thumbnail: Page 
860
    860
  • Thumbnail: Page 
861
    861
  • Thumbnail: Page 
862
    862