A high diversity in fossil beaked whales (Mammalia, Odontoceti, Ziphiidae) recovered by trawling from the sea floor off South Africa Author Bianucci, Giovanni Dipartimento di Scienze della Terra, Università di Pisa, via S. Maria, 53, I- 56126 Pisa (Italy) bianucci @ dst. unipi. it Author Lambert, Olivier Institut royal des Sciences naturelles de Belgique, Département de Paléontologie, rue Vautier, 29, B- 1000 Brussels (Belgium) olivier. lambert @ naturalsciences. be Author Post, Klaas Natuurhistorisch Museum Rotterdam, P. O. Box 23452, NL- 3001 Rotterdam (The Netherlands) klaas @ fiskano. nl klaas@fiskano.nl text Geodiversitas 2007 29 4 561 618 journal article 10.5281/zenodo.4651080 1638-9395 4651080 FA38C827-6C5F-4B70-B306-F30C90801A2F Genus Izikoziphius n. gen. TYPE SPECIES . — Izikoziphius rossi n. gen., n. sp. , by present designation. OTHER SPECIES INCLUDED . — Izikoziphius angustus n. gen., n. sp. ETYMOLOGY. — Iziko is the network of South African museums, which includes the South African Museum where most of the specimens studied here are stored, Ziphius is a Recent ziphiid genus. Gender masculine. DIAGNOSIS. — Izikoziphius n. gen. differs from all the other members of the Ziphiinae in the presence of a fossa on the anterior surface of the ascending process of the premaxilla distinct from the premaxillary sac fossa. It differs from Ziphius in: longer rostrum; lack of a prenarial basin; lesser asymmetry of the premaxillary sac fossae (<0.40) and longer contact between nasal and premaxillary crest. It differs from Tusciziphius in: the barely concave premaxillary sac fossa and the anterior part of the nasal not contacting the premaxillary crest. It differs from Choneziphius in: longer rostrum; premaxillae medially separated on the rostrum by the thickened vomer and barely concave premaxillary sac fossa. It differs from Caviziphius in: premaxillae medially separated on the rostrum by the thickened vomer; lower rostrum base and less asymmetric and barely concave premaxillary sac fossa. It differs from Aporotus , Beneziphius , Messapicetus , and Ziphirostrum in: longitudinally elongated nasals; premaxillae medially separated on the rostrum by the thickened vomer and lack of a constriction of the ascending process of the premaxilla (last character less clearly present in Messapicetus ). Both species of Izikoziphius n. gen. have a somewhat smaller cranium size than Ziphius cavirostris .