Acta Palaeontologica Polonica

A new basal sphenacodontid synapsid from the Late Carboniferous of the Saar-Nahe Basin, Germany

Jörg Fröbisch, Rainer R. Schoch, Johannes Müller, Thomas Schindler, and Dieter Schweiss

Acta Palaeontologica Polonica 56 (1), 2011: 113-120 doi:

A new basal sphenacodontid synapsid, represented by an anterior portion of a mandible, demonstrates for the first time the presence of amniotes in the largest European Permo−Carboniferous basin, the Saar−Nahe Basin. The new taxon, Cryptovenator hirschbergeri gen. et sp. nov., is autapomorphic in the extreme shortness and robustness of the lower jaw, with moderate heterodonty, including the absence of a greatly reduced first tooth and only a slight caniniform development of the second and third teeth. Cryptovenator shares with Dimetrodon, Sphenacodon, and Ctenospondylus, but notably not with Secodontosaurus, enlarged canines and a characteristic teardrop outline of the marginal teeth in lateral view, possession of a deep symphyseal region, and a strongly concave dorsal margin of the dentary. The new find shows that sphenacodontids were present in the Saar−Nahe Basin by the latest Carboniferous, predating the record of sphenacodontid tracks from slightly younger sediments in this region.

Key words: Synapsida, Sphenacodontidae, Carboniferous, Saar-Nahe Basin, Germany.

Jörg Fröbisch [], Department of Geology, The Field Museum, 1400 South Lake Shore Drive, Chicago, Illinois 60605, USA and and [joerg.froebisch@mfn−], Museum für Naturkunde Leibniz−Institut für Evolutions− und Biodiversitätsforschung an der Humboldt−Universität zu Berlin, Invalidenstr. 43, D−10115 Berlin, Germany; Rainer R. Schoch [], Staatliches Museum für Naturkunde, Rosenstein 1, D-70191 Stuttgart, Germany; Johannes Müller [], Museum für Naturkunde – Leibniz-Institut für Evolutions- und Biodiversitätsforschung an der Humboldt-Universität zu Berlin, Invalidenstr. 43, D-10115 Berlin, Germany; Thomas Schindler [], Büro für Paläontologie, Stratigraphie und Geotopschutz, Am Wald 11, D-55595 Spabrücken, Germany; Dieter Schweiss [], Geoskop Urweltmuseum, Burg Lichtenberg, D-66871 Thallichtenberg, Germany.