An unusual new fossil shark (Pisces: Chondrichthyes) from the Late Devonian of South Africa

WA Museum Records and Supplements | Updated 9 years ago

Abstract - A new stem-group chondrichthyan fish, Plesioselachus macracanthus gen. et sp. nov., is described from the Late Devonian Witpoort Formation, representing an estuarine lagoon site, near Grahamstown, South Africa. Based on a single, fairly complete specimen, it is distinctive in its a single dorsal fin braced by a large, stout spine with numerous ribs and posterior denticles, apparently no second dorsal or anal fin, an amphistylic jaw suspension, and a distinctive triangular palatoquadrate. It is suggested that the species may represent a high-latitude, Late Devonian relict taxon.