Basilosaurus
Cenozoic Era
65 million years ago to today
This early relative of modern whales had tiny hind legs. The legs, just 46 cm
(18 in) long, were evolutionary leftovers from its ancestors' life on land.
Whales evolved from four-legged land mammals that returned to the sea during
the Cenozoic Era. Basilosaurus had already evolved paddlelike forelimbs
and a streamlined body but lacked other attributes of modern whales such as
a blowhole at the top of its head. Seals, sea cows, walruses, and sea lions
all evolved from land mammals during this period. Their fossils are also on
display.
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| Life in the Ancient Seas Main Page |
Trilobite | Mosasaur | Gastropod |
