[Neoselachii] Compagno, 1977 - modern sharks and rays see Infraclass Elasmobranchii Bonaparte, 1838 Order Hexanchiformes Compagno, 1973 - six-gill sharks Family Hexanchidae Gray, 1851 - cow sharks Genus Notorynchus Ayres, 1855 [monotypic] 1 Notorynchus cepedianusᵀ (Péron, 1807) - bluntnose sevengill shark