ODONTOCETI FLOWER, 1867

Bianucci, Giovanni & Landini, Walter, 2006, Killer sperm whale: a new basal physeteroid (Mammalia, Cetacea) from the Late Miocene of Italy, Zoological Journal of the Linnean Society 148 (1), pp. 103-131 : 106

SUBORDER ODONTOCETI FLOWER, 1867 SUPERFAMILY PHYSETEROIDEA GRAY, 1821

Emended diagnosis: A superfamily of Odontoceti characterized by the following combined characters of the skull, ear bones and mandible: presence of a supracranial basin; strong asymmetry of skull emphasized by the posterior edge of the right premaxilla extending more posteriorly than the left; right premaxilla transversely widening and passing to the left side of the skull (character lacking because of reversal in the Kogiidae ); left premaxillary foramen either very small or absent, and one or two nasal bones lacking; antorbital notch deeply incised; frontal–maxilla suture, with skull in lateral view, angled posterodorsally and lateral exposure of frontal thickening posteriorly; zygomatic process of the squamosal triangular in lateral view with the dorsal margin dorsally bending in its posterior portion; anterior bullar facet of the tympanic bulla absent or very small; accessory ossicle present and partially fused with the anterior process of the periotic; involucrum with an evident central concavity, visible in ventral and medial views; fovea epitubaria of the periotic large and rectangular owing to the anteroposterior elongation of the accessory ossicle; anteroposteriorly elongated mandibular foramen; mandibular condyle located near the ventral margin. Moreover, the following combination of soft-tissue features characterizes the extant species: presence of a spermaceti organ; nasal passages not confluent distally to bony nares and characterized by a developed distal sac and by a proximal sac evolved into a frontal sac.