TYPE SPECIES. — Tusciziphius crispus Bianucci, 1997, from Tuscany (Italy), early Pliocene, calcareous nannofossil zone MNN14-15 (Bianucci et al. 2001).

OTHER SPECIES INCLUDED. — Tusciziphius atlanticus n. sp.

EMENDED DIAGNOSIS. — Tusciziphius differs from all other ziphiines except Imocetus n. gen. and Globicetus n. gen. in having an extremely ossified trapezoidal vertex in which the anterior part of the nasals contact the premaxillary crests. It differs from Globicetus n. gen. and Imocetus n. gen. in the extreme widening and anterior projection of the right premaxillary crest, and in the lesser posterior constriction of the vertex; it further differs from Globicetus n. gen. in lacking a large spherical medial premaxillary rostral prominence; it further differs from Imocetus in lacking a wide facial depression, a rostral maxillary spur-shaped crest, and in having the premaxillary foramen not located posterior to the level of the antorbital notch. Among the other ziphiine genera it further differs from Ziphius and Izikoziphius in the medial fusion of the premaxillae closing the mesorostral groove; it further differs from the possible ziphiine Caviziphius in the shallower excavation of the premaxillary sac fossae.