Science, Tech, Math › Animals & Nature Steller's Sea Cow Share Flipboard Email Print Steller's Sea Cow (Wikimedia Commons). Animals & Nature Dinosaurs Prehistoric Mammals Basics Paleontologists Carnivores Dinosaurs & Birds Herbivores Marine Reptiles Amphibians Birds Habitat Profiles Mammals Reptiles Wildlife Conservation Insects Marine Life Forestry Evolution View More By Bob Strauss Science Writer B.S., Cornell University Bob Strauss is a science writer and the author of several books, including "The Big Book of What, How and Why" and "A Field Guide to the Dinosaurs of North America." our editorial process Bob Strauss Updated March 17, 2017 Name: Steller's Sea Cow; also known as Hydrodamalis Habitat: Shores of the northern Pacific Historical Epoch: Pleistocene-Modern (2 million-200 years ago) Size and Weight: About 25-30 feet long and 8-10 tons Diet: Seaweed Distinguishing Characteristics: Enormous size; small, flexible head About Steller's Sea Cow Although it's much less well known than the Dodo Bird or the Giant Moa, Steller's Sea Cow (genus name Hydrodamalis) shared the unfortunate fate of these famous birds. Widespread across the northern Pacific Ocean for hundreds of thousands of years, by the mid-18th century this giant, 10-ton ancestor of modern dugongs and manatees was restricted to the obscure Commander Islands. There, in 1741, a population of a thousand or so survivors was studied by the early naturalist Georg Wilhelm Steller, who remarked on this megafauna mammal's tame disposition, undersized head perched on an oversized body, and exclusive diet of kelp (a type of seaweed). You can probably guess what happened next. As soon as word of Steller's Sea Cow got out, various sailors, hunters and traders made it a point to stop over at the Commander Islands and bag themselves a few of these gentle beasts, which were valued for their fur, their meat, and most of all their whale-like oil, which could be used to fuel lamps. Within three decades, Steller's Sea Cow had breathed its last; fortunately, though, Steller himself bequeathed his studies of live specimens on future generations of paleontologists. (It's important to realize that Steller's Sea Cow had been on the decline for tens of thousands of years before Europeans arrived on the scene; according to one theory, early human settlers of the Pacific Basin overhunted sea otters, thus allowing the unchecked proliferation of sea urchins, which feasted on the same kelp as Hydrodamalis!) By the way, it may yet be possible for scientists to resurrect Steller's Sea Cow by harvesting scraps of its fossil DNA, under a controversial research program known as de-extinction.