Hydrodamalis gigas (Steller's Seacow)

[Melanie]

The Giant Sea Mammal That Went Extinct in Less Than Three Decades

www.theatlantic.com/science/archive/2017/04/pleistoseacow/522831/

[surroundx]

Warner, Jeffery F., Harpole, Michael G. and Crerar, Lorelei D. (2017). Microsatellite Analysis for Identification of Individuals Using Bone from the Extinct Steller’s Sea Cow (Hydrodamalis gigas), pp. 205-217. In: Espina, Virginia (eds.). Molecular Profiling: Methods and Protocols (Methods in Molecular Biology series No. 1606). New York: Springer. [Abstract]

[surroundx]

Using Google Translator:

"In the Commander's Reserve (Kamchatka Territory) a skeleton of the extinct sea cow Steller

During the next survey of the coastline by the staff of the Commander's Reserve, a skeleton of the animal that had disappeared as far back as the 18th century - Steller's cow - was found. Several ribs could be seen from the coastal cliff, the skeleton was hidden under a layer of pebbles and sand at a depth of 70 cm.

Work on excavations lasted 4 hours by forces of 8 people. As a result, we managed to dig up the skeleton completely. All the bones were cleaned and marked for further assembly of the complete skeleton.

The found skeleton consists of 45 vertebrae, 27 ribs, left scapula, bones of the shoulder and forearm, several bones of the wrist. In the skeleton found, there was no skull, cervical spine, 1-2 thoracic vertebrae, several caudal vertebrae, right side of the thoracic extremities belt, as well as the bones of the pastern and phalanx of the fingers of the left extremity. The total length of the skeleton was 5.2 meters. Given the length of the missing parts of the vertebral column and head, it can be assumed that the total length of the animal was equal to or slightly greater than 6 meters.

The discovery of such a sufficiently complete skeleton of Steller's sea cow is an extremely important event not only for the Komandorsky reserve, but for science in general.

Currently, there are a lot of skeletons of the sea cow in the world's museums, but as a rule, all complete skeletons were discovered in the 19th century. The last find of the full skeleton of a 3-meter-long sea cow was made on the Bering Island in 1987. Some fragments of this skeleton are presented in the exposition of the Aleut Museum of Local History in the village of Nikolsky on the Bering Island.

The found skeleton will become one of the central exhibits of the visitor center of the Komandorsky reserve."

Source: www.mnr.gov.ru/news/detail.php?ID=343860

[Melanie]

Enormous Extinct Sea Cow Fossil Found on Russian Island
While lacking a head, the marine mammal bones could reveal more details about the little-known species.


news.nationalgeographic.com/2017/11/enormous-extinct-sea-cow-fossil-russian-island-spd/

[Melanie]

Ancient sea monster reappears on remote Russian island

siberiantimes.com/other/others/news/ancient-sea-monster-reappears-on-remote-russian-island/

[surroundx]

Sharko, Fedor S. et al. (In Press, 2018). Molecular phylogeny of the extinct Steller's sea cow and other Sirenia species based on their complete mitochondrial genomes. Genomics. doi.org/10.1016/j.ygeno.2018.10.012 [Abstract]

[Melanie]

Steller's sea cow: the first historical extinction of a marine mammal at human hands

www.nhm.ac.uk/discover/stellers-sea-cow-first-historical-extinction-of-marine-mammal-at-human-hands.html

[Melanie]

A Youtube video on Steller's seacow

[surroundx]

Renshaw, Graham. (1905). More Natural History Essays. London: Sherratt and Hughes.

[surroundx]

Bullen, Cameron David. (2020). A marine megafaunal extinction and its consequences for kelp forests of the North Pacific. Thesis, The University of British Columbia.

[surroundx]

Sharko, Fedor S. et al. (2021). Steller’s sea cow genome suggests this species began going extinct before the arrival of Paleolithic humans. Nature Communications 12: 2215.

[surroundx]

Le Duc, Diana et al. (2022). Genomic basis for skin phenotype and cold adaptation in the extinct Steller’s sea cow. Science Advances 8(5): eabl6496. doi.org/10.1126/sciadv.abl6496

[Melanie]

"Researchers reveal how extinct Steller's sea cow shaped kelp forests" phys.org/news/2022-11-reveal-extinct-steller-sea-cow.amp

[koeiyabe]

"Atlas of Extinct Animals (in Japanese)" by Radek Maly (2022)

[redpinnipedgamer]

I wonder if polar bears hunted steller sea cows, and if so if they did the same way they hunt belugas along the coast.

[Melanie]

I don't think that Steller's seacow belong to the prey of the Polar bear. First Steller's sea cow was much larger than any other animals in the Polar region, second they live largely under water and third they had a very thick layer of fat which makes it almost impossible for a Polar bear to kill a sea cow under water. If Polar bears hunt for walrusses they do it only on the ice shelf.

[Melanie]

Genus Hydrodamalis (Zimmermann, 1780)
Hydrodamalis gigas (Zimmermann, 1780)
Steller’s sea cow, manati marino
Monotypic.
Conservation: Hydrodamalis gigas is listed as Extinct by the IUCN (Domning 2016).
Characteristics: Steller’s sea cow is large sized; total length 8000–9000 mm, estimates of weight 24 tons. Hair on its body
was sparse and its skin was brownish-black, with white patches on some individuals; back is smooth, but flanks rough with
crater-like depressions most likely caused by parasites; tail fluke was forked; without dorsal fin; rostrum short; toothless.
Comments: Hydrodamalis gigas ranges only in the Bering Sea. Can be different from all other species by having tail fluke
was forked; without dorsal fin; rostrum short; toothless.

Sergio Ticul Álvarez-Castañeda Mammals of North America - Volume 1 Systematics and Taxonomy. Springer, 2024, p. 575