An extinct suborder comprising the oldest and most primitive cetaceans, which flourished in the Eocene and may have originated in Africa. Most were comparable in size with modern porpoises, had an elongated snout, and nostrils on top of the skull. The brain case was long and low. The front teeth were peg-like, the cheek teeth heterodont and characteristic of primitive carnivores. There were 44 teeth in all. The hind legs in most were reduced to vestiges, but in some early genera (Ambulocetus, Basilosaurus) still protruded from the body wall. They were fish-eating carnivores that had adopted an aquatic life to which they were more highly adapted than, for example, modern seals. The term archaeocete really means any primitive cetacean and probably does not designate a natural, monophyletic group.