Steller's Sea Cow Extinct

"When Commander Vitus Bering's ship St. Peter was wrecked on a remote, rocky island in 1741, the survive crew members found, in addition to bewhiskered sea otters, immense 'sea cows,' which were subsequently named for Bering's naturalist, Georg Wilhelm Steller. . . Steller's biographer. . . estimated that there were about 1,500. . . The animal, which could probably not dive below the surface, pulled itself along the shallows on its stumps as it browsed on kelp. Instead of teeth, the mouth of the sea cow was equipped with horny plates that it rubbed together to grind plant matter into a pulp. . . The sealers killed the huge, slow moving, oil-rich 'manatees' with such insensitive profligacy that there were none left by 1768."