Odobenocetops

Odobenocetops (/ˌoʊdəbiːˈnɒsɪtɒps/) is an extinct genus of small toothed whale that inhabited the southwestern coast of South America during the late Miocene. Two species of Odobenocetops are currently recognized, O. peruvianus and the slightly younger O. leptodon, both known from the Pisco Formation of Peru. More disarticulated, indeterminate remains are also known from the Bahía Inglesa Formation of Chile. Odobenocetops is mostly known for its large asymmetric tusks, which emerge from pronounced processes formed by the premaxillae, known as the alveolar sheaths. These tusks are thought to be sexually dimorphic and are only strongly pronounced in male individuals, while females appear to possess two similarly sized tusks. In the holotype of O. peruvianus the elongated right tusk is broken, leaving its precise length ambiguous. O. leptodon on the other hand preserves complete tusks, showing that at least in this species the longer tusk reached a total length of 1.35 metres (4 ft 5 in) long, 1.07 metres (3 ft 6 in) of which is located outside of the alveolar sheath. While these tusks are reminiscent of the tusk seen in the closely related narwhals, they evolved independently. Their purpose remains unknown, but the most common interpretation is that they served a non-violent social role, as they are too fragile for combat. The alveolar sheaths on the other hand may have been used as orientation guides during foraging.