Headless Skeleton Of Extinct Sea Cow The Size Of A Killer Whale Found In Siberia


Katy Evans

Katy is Managing Editor at IFLScience where she oversees editorial content from News articles to Features, and even occasionally writes some.

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This specimen would have been 20 feet long, when it still had its head. Commander Islands Nature and Biosphere Reserve

Up until the 18th century, a ginormous but gentle sea “monster” languished in the Arctic waters of the Bering Sea, off the coast of Russia. Until, we hunted it to extinction, of course.

The Steller's sea cow was only discovered in 1741 and just 27 years later it was no more. Since then it has kind of flummoxed scientists as we don’t know very much about it.


Now, one of the most complete skeletons of the gentle giant (albeit sadly missing a head) has been discovered on a lonely beach on one of the Commander Islands of Siberia, revealing a creature estimated to be around 6 meters (20 feet) in length – the size of a killer whale.

The bones of the giant ribcage were first spotted by Marina Shitova of the Commander Islands Nature Reserve, protruding out of the sand. She described seeing what looked like fence poles jutting out of the ground.

Commander Islands Nature and Biosphere Reserve

After just 4 hours of digging in less than a meter (3 feet) of earth, Shitova and her team had exhumed the 5-meter-long (17 feet) skeleton of the massive marine mammal. Surprisingly well-preserved, it includes 45 vertebrae, 27 ribs, and a left scapula. Sadly no head was discovered, but they haven’t given up hope of finding it in the surrounding area.

Commander Islands Nature and Biosphere Reserve

The Steller's sea cow, part of the sirenian order that includes dugongs and manatees, was one of the last Pleistocene megafaunas, and the largest mammal of the Holocene, barring cetaceans. It could grow up to 10 meters (30 feet) and weighed around 10 tonnes (11 US tons).


It was named after Georg Steller, the German naturalist and explorer who discovered it in 1741. He had some interesting ideas about the creature, including that it may have walked on land – which isn’t actually that crazy seeing as sea cows are members of the paenungulates clade, just like elephants and hyraxes.

An illustration of a Steller's sea cow (Hydrodamalis gigas) from the book "Extinct Monsters", by the Rev. H.N. Hutchinson (London, 1893). Biodiversity Heritage Library (CC By) Creative Commons

They were endemic to the seas between Siberia and Alaska, and when Steller revealed to the world his discovery, sadly they became prize hunting due to their abundance of meat and skin, but also because they were slow and gentle, and so rather easy to kill.

File:Steller measuring a sea cow.jpg
Reconstruction of Steller measuring a Steller's sea cow on Bering Island, July 12, 1742, published in Steller's Journal of the Sea Voyage from Kamchatka to America.

Skeletons of the giant marine mammals are rare these days, with a museum in Finland the only known place to hold an intact skeleton that isn’t a composite of many different individuals. This new one will go on display at the Komandorsky Nature Reserve, to not only educate people about the natural history of the Commander Islands, but to remind people of the awesome megafauna that once roamed the earth, and that our actions have consequences.


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  • fossil,

  • manatee,

  • steller's sea cow,

  • commander islands