Little was known about the Steller’s sea cow ()as it became extinct just 27 years after it was discovered by a Russian explorer, Captain Vitus Bering, in 1741. It was the largest of the sirenians (a group of marine mammals that includes manatees and dugongs).

When the sea cow was discovered in Alaska, it was already rare; there were perhaps 1,000 to 2,000 individuals. Bering’s crew killed many of the remaining sea cows for their meat and hides, as their ship was stranded in Alaska and they were forced to remain there. Subsequent expeditions to the area killed the rest. The Steller’s sea cow probably was extinct by 1768.