With a skull as long as a sofa and a total body length equivalent to that of three elephants, this early whale was at the top of the underwater food chain. To maintain its incredible weight — it was as heavy as two tanks — Basilosaurus was an eating machine that could swallow sharks whole. Fossils also show a reminder of its land-animal ancestors: a pair of tiny back legs.

PRONUNCIATION: BASS-IL-OH-SAWR-US
LIVED: 40 – 36 million years ago
SIZE: 66 feet long
FACT: Carnivorous, feeding on fish, sharks, mollusks and cetaceans
MEANING: King lizard
CLOSEST LIVING RELATIVE: Whales
RANGE: North America and North Africa