Steller’s Sea Cow

Hydrodamalis gigas. Also giant sea cow, formerly borkentier. Northern Pacific. 1897.

Of the 27 extant skeletons of this extinct species worldwide, none is complete. The almost complete specimen at the NHM is the only one with pelvic bones.

1741–1768
German doctor and naturalist Georg Wilhelm Steller was the first and only scientist ever to have seen a living example of the sea cow that is named after him. He observed the enormous creatures near Bering Island off the Kamtchatka Peninsula, where he was stranded with a Russian expedition ship in 1741.
His publications helped attract the attention of Russian fur trappers to this tasty food source. The preferred shallow-water feeding sites of the sea cow were soon found, and the animal was avidly hunted. Harpooning the colossus and hauling it on shore with ropes required at least ten men. As the animals were extremely trusting, could not dive deep, and could not escape into the open sea, they could be overwhelmed with relatively little effort. Just 27 years after their discovery, the easily caught giants had been eradicated. What we know about them today is based above all on Georg Steller’s detailed descriptions, on two small pieces of skin and a few skeletons at museums.
The Steller sea cow was up to eight meters long and weighed about four tons. It had extremely tough skin and fed on kelp. In addition to small forelimbs and a broad, whale-like tail, other characteristic features of the species were a particularly thick layer of fat. Steller sea cows were very social, gregarious animals who came to the aid of injured members of their species, which – combined with their site fidelity and their slow rate of reproduction – was a significant factor in their rapid elimination.