Although Ambulocetus looked like a furry crocodile or a giant otter, it was actually an early whale.

Meaning of scientific name
"walking whale" (natans = "that swims").

Pronunciation of scientific name
am-byu-lo-SEE-tus

Statistics
3m long.

Physical description
Although Ambulocetus looked rather like a huge otter, it was in fact one of the earliest whales. It had a long, low body with short, powerful limbs. Its back legs in particular seemed to be used for propulsion, and its feet had long, probably webbed toes (each ending in a tiny hooflet). Its tail was slightly flattened, like that of an otter, to help it swim. Its eyes and nostrils were on the top of its skull, allowing it to see and breathe whilst partly submerged, and it had a fearsome set of teeth.

Distribution
One fairly complete specimen and several partial skeletons have been found in Pakistan.

Habitat
Swam in the estuaries and rivers on the northern shores of the Tethys Ocean separating Africa and Eurasia.

Diet
Carnivorous - eating quite large animals.

Behaviour
Ambulocetus was not as agile in the water as an otter, and seems to be adapted for ambushing large prey, which it then drowned. Its skull shows adaptations for holding large, struggling prey underwater. Its ear bones also show that it did not have external ears but instead used the same method of hearing as modern whales do - picking up vibrations through the jawbone. It may have used this technique to listen for prey walking along the shore by resting its head on the ground.

Conservation status
Extinct.

History
Ambulocetus lived 50-49 million years ago and was descended from land-living carnivorous hoofed animals such as the dog-like Pakicetus.

Closest relative
Most closely related to modern whales, but also related to cloven hoofed animals (artiodactyls).