Otodus obliquus was one of the major marine predators of the Palaeocene and early Eocene and an early member of the otodontid lineage that later gave rise to the giant megatooth sharks. It was a large, powerful lamniform with a feeding apparatus built for tackling substantial prey.

Its thick triangular teeth had smooth cutting edges and strong lateral cusplets. Working together, they formed a robust grasping-and-cutting dentition capable of penetrating flesh and retaining large prey. Fishes and other marine vertebrates are likely food sources, although direct evidence of individual prey is rare.

O. obliquus was widespread across warm seas and was not simply a local London Clay animal. Its occurrence there places a major open-water predator alongside a remarkably diverse community of smaller sharks and rays.