sentences:  Cetaceans are descended from land-dwelling hoofed mammals, and the now extinct archaeocetes represent the several transitional phases from terrestrial to completely aquatic.Historically, cetaceans were thought to have descended from the wolf-like mesonychids, but cladistic analyses confirm their placement with even-toed ungulates in the order Cetartiodactyla.Whale populations were drastically reduced in the 20th century from intensive whaling, and the activity was globally banned in 1982.