Steller's sea cow (Hydrodamalis gigas) was a large sirenian mammal that was once abundant throughout the North Pacific but was limited to the Commander Islands by 1741. Within 27 years of being discovered by Europeans, the slow moving sea cow was hunted to extinction for food and oil. It grew up to 8 meters long, looked like a large seal but with forelimbs and a whale-like tail. It lived in the water and fed on kelp. The sole remaining population was hunted to extinction by 1768 for its meat and fat.

1. Steller's sea cow Martí & Javier 4B

3. Description The sea cow grew at least 8 metres long, much larger than the manatee or dugong. Steller's work contains two contradictory weights: 4 and 24.3 tons. The true value probably lies between these figures, around 8-10 tons. It looked somewhat like a large seal, but had two stout forelimbs and a whale-like tail. According to Steller, "The animal never comes out on shore, but always lives in the water. Its skin is black and thick, like the bark of an old oak, its head in proportion to the body is small…, it has no teeth, but only two flat white bones- one above, the other below". It was completely tame, according to Steller. They fed on a variety of kelp. Wherever sea cows had been feeding, heaps of stalks and roots of kelp were washed ashore. The sea cow was also a slow swimmer and apparently was unable to submerge.

4. Habitat The steller's sea cow, lived in the Indian Ocean and part of the Pacific, from Taiwan to New Guinea. Many years ago, about 12.000, this huge animal lived around all the seas and oceans, from Japan to California, but at the final of a period, the animal only lived at major's Islands, near the north pacific.

5. Causes of extinction The steller's sea cow became extincted because the sailors that were at the Commander Islands hunted them to eat, and to have them fat to make oil lamps. In 27 years, the steller's sea cow became extincted.