Before migrating to the sea, whales were terrestrial herbivores. As they transitioned to the ocean and became carnivores, at least one proto-whale was an eating machine — both on land and in the sea. This fearsome fossil was found in the Sahara desert, which used to be an ocean bottom. Whales are carnivorous , although gigantic baleen whales feed on such tiny prey that it is hard to believe that they ever get enough food. Toothed whales dine on fish, squid, and octopi. (Fun fact: Orcas, also known as killer whales, are not really whales — they are gigantic, killer dolphins.) Before moving into the sea, it is believed that whales were once terrestrial herbivores and somewhat deer-like. About 43 million years ago, say the authors of a new study , at least one protocetid — a semi-aquatic whal
