Physeter sp. Linnaeus, 1758

Fitzgerald, Erich M. G., 2005, Pliocene marine mammals from the Whalers Bluff Formation of Portland, Victoria, Australia, Memoirs of Museum Victoria 62 (1), pp. 67-89 : 74

cf. Physeter sp. Linnaeus, 1758

Referred specimen. NMV P218298, isolated, worn-down apical region of tooth crown ( Fig. 3C ).

Description. P218298 has an ovoid cross-section at its base which becomes more ellipsoid towards the preserved apex of the crown. In occlusal view, the apex of the tooth crown is incised by a deep anteroposterior cleft which is attributed to tooth wear. Shallow longitudinal grooves in the surface occur on all faces of the crown. The basal end of the tooth is broken to reveal a cross-section through the crown. The only notable feature of this aspect of the tooth is the presence of thick layers of cementum.

Discussion. The large size of this tooth and the thick layers of cementum suggest that P218298 represents a physeterid. Little more can be said about the systematics of this specimen although its size and similarity to teeth of large adult Physeter macrocephalus suggest affinities with the extant sperm whale.

Figures

Figure 3. Mysticeti and Physeteridae from the Pliocene Whalers Bluff Formation, Portland. A, Balaenidae gen. et sp. indet., incomplete right periotic, NMV P218269, in ventrolateral view (AC); B, Balaenopteridae gen. et sp. indet., incomplete right periotic, NMV P218268, in ventral view (AC); C, cf. Physeter sp., apical crown of tooth, NMV P218298, in side view (AC). Scale bars equal 10 mm.