Dorudon ("Spear-Tooth") is a genus of extinct basilosaurid ancient whales that lived alongside Basilosaurus 40.4 to 33.9 million years ago, in the Eocene. They were about 5 m (16 ft) long and fed on small fish and mollusks. Dorudon lived in warm seas around the world. Fossils have been found along the former shorelines of the Tethys Sea in present-day Egypt and Pakistan, as well as in the United States, New Zealand, and Western Sahara.