Morawanocetus is a genus of extinct primitive baleen whale from the family Aetiocetidae that existed during the Chattian stage of the Oligocene epoch. Its fossils have been found in the North Pacific. Morawanocetus was named by Barnes et al. in 1995, who described the species, M. yabukii. Three new species, dating from 17 to 19 million years ago, were unearthed between 2000 and 2005 in a road-widening project in California. These three new specimens of Morawanocetus, a genus thought to have gone extinct some five million years earlier, were discovered next to a fourth specimen, still under preparation, which clearly has archaeocete dentition.