1. WhalE Evolution An example of Secondary Evolution
(started in the water, went on land, returned to the water)

2. Odontoceti (toothed whales)
Evolved from
a wolf-like ancestor
about 50 million years ago
Used to think they
had evolved from a
bear-like animal…

3. Pakicetus

4. Pakicetus
Toes

5. Ambulocetus
Ambulocetus means ‘walking whale’. It lived 49 million years ago in Pakistan.
It had the legs of its terrestrial ancestors and the body of a primitive whale. (10 feet long).

6. Basilosaurus isis 40 million year old, 50 foot long whale from
Egypt. It still
had tiny hind legs.
Legs

7. Dr. B. Holly Smith working at the base of the tail of a weathered Basilosaurus isis in Wadi Hitan, Egypt. This is the part of the skeleton where the reduced hind limbs, feet, and toes were found. Photograph ©1991 Philip Gingerich. (U. of Michigan)

8. Mysticeti (baleen whales)
Evolved from a small
deer-like ancestor (Indohyus)
about 50 million years ago
Used to think they
had evolved from a
cow or hippo-like animal…