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Naturwissenschaften

, Volume 98, Issue 12, pp 1027–1034 | Cite as

The last “pelycosaur”: a varanopid synapsid from the Pristerognathus Assemblage Zone, Middle Permian of South Africa

  • Sean P. Modesto
  • Roger M. H. Smith
  • Nicolás E. Campione
  • Robert R. Reisz
Original Paper

Abstract

We report on a partial varanopid skull and mandible from the Pristerognathus Assemblage Zone of the Beaufort Group, in the South African Karoo Basin, which is probably latest Middle Permian (Capitanian) in age. This mycterosaurine is not only the youngest known varanopid from the Southern Hemisphere, but it is also the youngest known “pelycosaur” (i.e., non-therapsid synapsid). Like all other members of this clade of hypercarnivores, the teeth are strongly flattened, recurved, and have finely serrated cutting edges. The anterior dentary teeth form a caniniform region, and the splenial features a foramen intermandibularis oralis, the first ever to be described in a “pelycosaur.” The last varanopids were the smallest carnivores of latest Middle Permian continental faunas. Occupation of the small carnivore guild appears to have allowed varanopids to achieve a nearly cosmopolitan distribution throughout the Middle Permian, between the great Early Permian radiation of basal synapsids and the spectacular diversification of therapsid synapsids in the Late Permian and Early Triassic.

Keywords

Paleozoic tetrapods Synapsida Varanopidae Paleobiogeography South Africa 

Notes

Acknowledgments

We thank Hedi Stummer and Annelise Crean for initial preparation of SAM-PK-K10407; Diane Scott for the photo images that appear in the Figures and Online Resource 1 of the Electronic supplementary material, and Nicola Wong Ken for additional preparation and the illustration of SAM-PK-K10407 and for the skull reconstruction seen in Fig. 3. Sheena Kaal is also thanked for supplemental locality data. This research was supported by Discovery Grants from the Natural Sciences and Engineering Research Council of Canada (to SPM and RRR).

Supplementary material

114_2011_856_MOESM1_ESM.doc (3.8 mb)
ESM 1 (DOC 3916 kb)

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Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Sean P. Modesto
    • 1
  • Roger M. H. Smith
    • 2
  • Nicolás E. Campione
    • 3
  • Robert R. Reisz
    • 4
  1. 1.Department of BiologyCape Breton UniversitySydneyCanada
  2. 2.Karoo PalaeontologyIziko: South African MuseumCape TownSouth Africa
  3. 3.Department of Ecology and Evolutionary BiologyUniversity of TorontoTorontoCanada
  4. 4.Department of BiologyUniversity of Toronto at MississaugaMississaugaCanada

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