Steller's sea cow
|Steller's sea cow
Temporal range: Pleistocene-Recent
|Drawing of a dead female published by Peter Simon Pallas in 1840, thought to be the only one drawn from an actual specimen|
|Map showing the position of the Commander Islands to the east of Kamchatka. The larger island to the west is Bering Island; the smaller island to the east is Copper Island.|
Steller's sea cow (Hydrodamalis gigas) is an extinct species of sirenian discovered in 1741. At the time of its discovery, the sea cow was found only around the Commander Islands, located in the Bering Sea between Alaska and Russia, however this may have been more expansive during the Pleistocene epoch. During the Holocene epoch it was among the largest mammals, reaching weights of 8–10 metric tons (8.8–11.0 short tons) and lengths of up to 9 metres (30 ft). The sea cow was a member of the family Dugongidae, of which its closest living relative, the dugong (Dugong dugon), is the sole surviving member.
Steller's sea cow had a thicker layer of blubber than other members of the order. This adaptation was due to the cold waters of its environment. The sea cow's tail was forked, like that of cetaceans. The sea cow did not have teeth, instead having an array of white bristles on its upper lip and two keratinous plates within its mouth for chewing. Steller's sea cow fed mainly on kelp, and communicated via sighs and snorting sounds. Evidence shows the sea cow was likely a monogamous and social animal, living in small family groups and raising its young, similar to extant sirenians.
The sea cow was named for Georg Wilhelm Steller, a naturalist who discovered the species in 1741. The discovery came on Vitus Bering's Great Northern Expedition when the crew became shipwrecked on Bering Island. Much of what is known about the behavior of the sea cow comes from Steller's observations on the island, documented in his posthumous publication The Beasts of the Sea. Within 27 years of discovery by Europeans, the slow-moving and easily caught Steller's sea cow was hunted into extinction for its meat, fat, and hide. However, sightings have been claimed post-1768, the recorded year of its extinction.
Steller's sea cows grew to be 8 to 9 m (26 to 30 ft) long as adults, much larger than extant sirenians. As for weight, Georg Steller's writings contain two contradictory estimates: 4 and 24.3 metric tons (4.4 and 26.8 short tons). The true value is estimated to fall between these figures, at about 8–10 metric tons (8.8–11.0 short tons). This size made the sea cow one of the largest mammals of the Holocene epoch, aside from whales. The sea cow's large size was likely an adaptation to reduce its surface-area-to-volume ratio and conserve heat. Unlike other sirenians, Steller's sea cow was positively buoyant, meaning it was unable to completely submerge. It had a very thick outer skin (2.5 centimetres (1 in)) to prevent injury from sharp rocks and ice, and possibly to prevent unsubmerged skin from drying out. The sea cow's blubber was 8–10 centimetres (3–4 in) thick, another adaptation to the frigid climate of the Berring Sea where it lived. Its skin was brownish-black in color, with white patches on some individuals. Its skin was smooth along its back and rough on its sides, with crater-like depressions most likely caused by parasites. This rough texture led to the animal being nicknamed the "bark animal." Hair on its body was sparse, but the insides of the sea cow's flippers were covered in bristles. Its the forelimbs were roughly 67 centimetres (26 in) long, and its tail fluke was forked.
The sea cow's head was small and short in comparison to its huge body. The animal's upper lip was large and broad, extending so far beyond the lower jaw that the mouth appeared to be located underneath the skull. Unlike other sirenians, Steller's sea cow was toothless and instead had a dense array of interlacing white bristles on its upper lip. The bristles were approximately 3.8 centimetres (1.5 in) in length and were used to tear seaweed stalks and hold food. The sea cow also had two keratinous plates located on its palate and mandible used for chewing. According to Steller, these plates (or "masticatory pads"), were held together by interdental papillae, a part of the gums, and had many small holes containing nerves and arteries.
As with all sirenians, the sea cow's snout pointed downwards, which allowed it to better grasp kelp. The sea cow's nostrils were roughly 5 centimetres (2 in) long and wide. In addition to those within its mouth, the sea cow also had stiff, 10–12.7 centimetres (3.9–5.0 in) long bristles protruding from its muzzle. Steller's sea cow had small eyes located halfway between its nostrils and ears with black irises, livid eyeballs, and canthi which were not externally visible. The animal had no eyelashes, but like other diving creatures such as sea otters, Steller's sea cow had a membrane which covered its eyes to prevent injury while feeding. Its tongue was rough with small bumps (lingual papillae) giving it texture. The tongue was only 30 centimetres (12 in) in length and remained in the back of the mouth, unable to reach the masticatory (chewing) pads.
The sea cow's spine is believed to have had 7 neck, 17 thoracic, 3 lumbar, and 34 caudal (tail) vertebrae. Its ribs were large, with 5 of 17 pairs making contact with the sternum; the sea cow had no clavicles. As in all sirenians, the scapula of Steller's sea cow was fan-shaped-- larger on the posterior side and narrower towards the neck. However, the anterior border of the scapula was nearly straight, whereas those of modern sirenians are curved. Like most sirenians, the bones of Steller's sea cow were pachyosteosclerotic, meaning they were both bulky (pachyostotic) and dense (osteosclerotic). In all collected skeletons of the sea cow, the manus is missing: since Dusisiren, the sister taxon of Hydrodamalis, had reduced phalanges (finger bones), it is possible that Steller's sea cow did not have a manus at all.
The sea cow's heart was 16 kilograms (35 lb) in weight, while its stomach measured 1.8 metres (6 ft) long and 1.5 metres (5 ft) wide. The full length of its intestinal tract was about 151 metres (500 ft) long, equaling more than 20 times the animal's length. The sea cow had no gallbladder, but did have a wide common bile duct. Its anus was 10 centimetres (0.33 ft) in width, with its feces resembling that of horses. In males, the penis was 81 centimetres (2.7 ft) long.
Ecology and behavior
Whether Steller's sea cow had any natural predators is unknown. It may have been hunted by killer whales and sharks, though its buoyancy may have made it difficult for killer whales to drown it, and the rocky kelp forests the sea cow lived in may have deterred sharks. According to Steller, the adults guarded the young from predators.
Steller described an ectoparasite on the sea cows which was similar to the whale louse (Cyamus ovalis), but the parasite remains unidentified due to the host's extinction and loss of all original specimens collected by Steller. Apparently, these parasites were picked off and eaten by seagulls as part of a symbiotic relationship. Steller also identified an endoparasite on the sea cows, which were likely ascarid nematodes.
Like other sirenians, Steller's sea cow was an obligate herbivore and spent most of the day feeding, only lifting its head every 4 to 5 minutes for breathing. Kelp was its main food source, making it an algivore. The sea cow likely fed on several species of kelp, which have been identified as: Agarum spp., Alaria praelonga, Halosaccion glandiforme, Laminaria saccharina, Nereocyctis luetkeana and Thalassiophyllum clathrus. Steller's sea cow only fed directly on the soft parts of the kelp, which caused the tougher stem and holdfast to wash up on the shore in heaps. The sea cow may have also fed on seagrass, but the plant was not common enough to support a viable population and could not have been the sea cow's primary food source. Further, the available seagrasses in the sea cow's range (Phyllospadix spp. and Zostera marina) may have grown too deep underwater or been too tough for the animal to consume. Since the sea cow floated, it likely fed on canopy kelp, as it is believed to have only had access to food no deeper than 1 metre (3.3 ft) below the tide. Kelp releases a chemical deterrent to protect it from grazing, but canopy kelp releases a lower concentration of the chemical, allowing the sea cow to graze safely. Steller noted that the sea cow grew thin during the frigid winters, indicating a period of fasting due to low kelp growth. Fossils of Pleistocene Aleutian Island sea cow populations were larger than those from the Commander Islands, indicating that the growth of Commander Island sea cows may have been stunted due to a less favorable habitat and less food than the warmer Aleutian Islands.
Steller described the sea cow as being highly social (gregarious). The sea cow lived in small family groups and helped injured members, while also apparently being monogamous. Steller's sea cow may have exhibited parental care, and the young were kept at the front of the herd for protection against predators. Steller reported that as a female was being captured, a group of other sea cows attacked the hunting boat by ramming and rocking it, and after the hunt, her mate followed the boat to shore, even after the captured animal had died. Mating season occurred in early spring and gestation took a little over a year, with calves likely delivered in autumn, as Steller noted that he observed a greater number of calves in autumn than at any other time of the year. Since female sea cows had only one set of mammary glands, it is likely that they had one calf at a time.
The sea cow used its forelimbs for swimming, feeding, walking in shallow water, defending itself, and for holding on to its partner during copulation. According to Steller, the forelimbs were also used to anchor the sea cow down to prevent it from being swept away by the strong nearshore waves. While grazing, the sea cow progressed slowly by moving its tail (fluke) from side to side, while more rapid movement was achieved by strong vertical beating of the tail. For sleep the sea cow went further out to sea to prevent beaching itself when the tides receded. According to Steller, the sea cow was nearly mute and made only heavy breathing sounds, raspy snorting similar to a horse, and sighs.
|Relations within Sirenia|
|Based on a 2015 study by Mark Springer|
|Relations within Hydrodamalinae|
|Based on a 2004 study by Hitoshi Furusawa|
Steller's sea cow was a member of the genus Hydrodamalis, a group of large sirenians, whose sister taxon was Dusisiren. Like those of Steller's sea cow, the ancestors of Dusisiren lived in tropical mangroves before adapting to the cold climates of the North Pacific. Hydrodamalis and Dusisiren are classified together in the subfamily Hydrodamalinae. Steller's sea cow is a member of the family Dugongidae, whose sole surviving member, and thus Steller's sea cow's closest living relative, is the dugong (Dugong dugon).
Steller's sea cow was a direct descendant of the Cuesta sea cow (H. cuestae), an extinct tropical sea cow that lived off the coast of western North America, particularly California. The Cuesta sea cow is thought to have gone extinct due to the onset of the Ice Ages and the subsequent cooling of the oceans. Many lineages died out, while the lineage of Steller's sea cow was able to adapt to the colder temperatures. The Takikawa sea cow (H. spissa) of Japan is thought of by some researchers to be a taxonomic synonym of the Cuesta sea cow, but based on a comparison of endocasts, the Takikawa and Steller's sea cows are more derived than the Cuesta sea cow. This has led some to believe that the Takikawa sea cow is its own species. The evolution of the Hydrodamalis genus was characterized by increased size and a loss of teeth and phalanges as a response to the onset of the Ice Ages.
Steller's sea cow was discovered in the mid-18th century (1741) by Georg Wilhelm Steller, and was subsequently named after him. Steller researched the wildlife of Bering Island while he was shipwrecked there for about a year; the animals on the island included relict populations of sea cows, sea otters, Steller sea lions, and northern fur seals. Steller's account was written in his posthumous publication De bestiis marinis, or The Beasts of the Sea, which was published in 1751 by the Russian Academy of Sciences in St. Petersburg. Zoologist Eberhard von Zimmermann described the sea cow's specific name as gigas in 1780, and placed it in the genus Manati. Biologist Anders Jahan Retzius, however, put the sea cow in the genus Hydrodamalis, with the specific name of stelleri, in honor of Steller. In 1811, naturalist Johann Karl Wilhelm Illiger reclassified Steller's sea cow into the genus Rytina, which many writers at the time adopted, despite the sea cow having already been classified. The name Hydrodamalis gigas was first used in 1895 by Theodore Sherman Palmer.
For decades after its discovery, no skeletal remains of a Steller's sea cow were discovered. This may have been due to rising and falling sea levels over the course of the Quaternary period, which could have left many sea cow bones hidden. The first bones of a Steller's sea cow were unearthed in about 1840, over 70 years after it was presumed extinct. The first partial sea cow skull was discovered in 1844 by Ilya Voznesensky while on the Commander Islands, and the first skeleton was discovered in 1855 on northern Bering Island. These specimens were sent to St. Petersburg in 1857, and another nearly complete skeleton arrived in Moscow around 1860. Most of the skeletal remains were unearthed in the late 1800s: between 1878 and 1883, 12 of the known 27 skeletons were discovered. Adolf Erik Nordenskiöld, Benedykt Dybowski, and Leonhard Hess Stejneger each unearthed many bones from different individuals during this period, from which composite skeletons were assembled. As of 2006, 27 nearly complete skeletons and 62 complete skulls have been found.
The Pallas Picture (shown below) is the only known drawing of Steller's sea cow believed to be from an actual specimen. It was published by Peter Simon Pallas in his 1840 work Icones ad Zoographia Rosso-Asiatica. While Pallas did not specify a source, Stejneger suggested it may have been one of the original illustrations produced by Friedrich Plenisner, a member of Vitus Bering's as a painter and surveyor who drew a figure of a female sea cow on Steller's request. Most of Plenisner's depictions were lost during transit from Siberia to St. Petersburg.
Another drawing of Steller's sea cow similar to the Pallas Picture appeared on a 1744 map drawn by Sven Waxell and Sofron Chitrow. The picture may have also been based upon an actual specimen, and was published in 1893 by Pekarski. The map depicted Vitus Bering's route during the Great Northern Expedition, and featured illustrations of Steller's sea cow and Steller's sea lion in the upper-left corner. However, the drawing contains some inaccurate features such as the inclusion of eyelids and fingers, bringing doubt that it was drawn from a specimen.
Johann Friedrich von Brandt, director of the Russian Academy of Sciences had the "Ideal Image" drawn in 1846 based upon the Pallas Picture, and then the "Ideal Picture" in 1868 based upon collected skeletons. Two other possible drawings of Steller's sea cow were found in 1891 in Waxell's manuscript diary. There was a map depicting a sea cow, as well as Steller's sea lion and a northern fur seal. The sea cow was depicted with large eyes, a large head, claw-like hands, exaggerated folds on the body, and a tail fluke in perspective lying horizontally rather than vertically. The drawing may have been a distorted depiction of a juvenile, as the figure bears a resemblance to a manatee calf. Another similar image was found by Alexander von Middendorff in 1867 in the library of the Russian Academy of Sciences, and is probably a copy of the Tsarskoye Selo Picture.
|Early depictions of Steller's sea cow|
|Locations of confirmed sightings and fossil remains of Steller's sea cow|
The range of Steller's sea cow at the time of its discovery was apparently restricted to the shallow seas around the Commander Islands, which include Bering and Copper Islands. The Commander Islands remained uninhabited until 1825 the Russian-American Company relocated Aleuts from Attu Island and Atka Island there. The first fossils discovered outside the Commander Islands were found in interglacial Pleistocene deposits in Amchitka, and further fossils dating to the late Pleistocene were found in Monterey Bay, California, and Honshu, Japan. This suggests that the sea cow had a far more extensive range in prehistoric times. However, it cannot be excluded that these fossils belong to other Hydrodamalis species. The remains of three individuals were found preserved in the South Bight Formation of Amchitka; as late Pleistocene interglacial deposits are rare in the Aleutians, the discovery suggests that sea cows were abundant in the that era. According to Steller, the sea cow often resided in the shallow, sandy shorelines and in the mouths of freshwater rivers.
Bone fragments and accounts by native Aleut people suggest that sea cows also historically inhabited the Near Islands, potentially with viable populations that were in contact with humans in the western Aleutian Islands prior to Steller's discovery in 1741. A sea cow rib discovered in 1998 on Kiska Island was dated to around 1,000 years old, and is now in the possession of the Burke Museum in Seattle. However, the dating may be skewed due to the marine reservoir effect which causes radiocarbon-dated marine specimens to appear several hundred years older than they actually are. Marine reservoir effect is caused by the large reserves of C14 in the ocean, and it is more likely that the animal died between 1710 and 1785.
A 2004 study reported that sea cow bones discovered on Adak and Buldir Islands were found to be around 1,700 and 1,600 years old respectively. However it is possible the bones were from cetaceans and were misclassified. Rib bones of a Steller's sea cow have also been found on St. Lawrence Island, and the specimen is thought to have lived between 800 and 920 CE.
Interactions with humans
The presence of Steller's sea cows in the Aleutian Islands may have caused the Aleut people to migrate westward to hunt them, possibly leading to the sea cow's extinction in that area, assuming the animals survived in that region into the Holocene epoch.
The first attempt to hunt Steller's sea cow by Steller and the other crew members was unsuccessful due to the animal's strength and its thick hide. The attempted method was to impale the sea cow and haul it to shore using a large hook and heavy cable, but the crew could not pierce the skin. The second attempt did not occur until a month later, when a harpooner speared the animal, and men on shore hauled it in while others repeatedly stabbed it with bayonets. The sea cow was dragged into shallow waters, and the crew waited until the tide receded and the animal beached itself to butcher it. After this, they hunted Steller's sea cows with relative ease, the challenge being in hauling the animal back to shore. This success in hunting sea cows inspired maritime fur traders to detour to the Commander Islands and restock their food supplies during North Pacific expeditions .
Steller's sea cow was quickly wiped out by fur traders, seal hunters, and others who followed Vitus Bering's route past the sea cow's habitat and to Alaska. It was also hunted to collect its valuable subcutaneous fat. By 1768, 27 years after it had been discovered by Europeans, Steller's sea cow was extinct.
It has also been argued that the decline of Steller's sea cow may have been an indirect effect of the harvesting of sea otters by the aboriginal peoples. With the otter population reduced, the number of sea urchins would have increased, in turn reducing availability of kelp, as kelp is also the main food source for sea urchins. Therefore, aboriginal hunting of otters may have contributed to the sea cow's disappearance from continental shorelines. In historic times, though, aboriginal hunting had depleted sea otter populations only in localized areas, and as the sea cow would have been easy prey for aboriginal hunters, accessible populations may have been exterminated with or without simultaneous otter hunting. In any event, the range of the sea cow was limited to coastal areas off uninhabited islands by the time Bering arrived, and the animal was already endangered. In 1887 Stejneger estimated that there had been fewer than 1,500 individuals remaining at the time of Steller's discovery, and thus there was already an immediate danger of the sea cow's extinction.
Another event potentially leading to extinction of Steller's sea cow, specifically off the coast of St. Lawrence Island, was the onset of the Medieval Warm Period which reduced the availability of kelp. However, the Siberian Yupik people who have inhabited St. Lawrence island for 2,000 years may have simply hunted the sea cows into extinction, as the natives have a dietary culture heavily dependent upon marine mammals.
Steller reported that he had found whole Steller's sea cow skeletons washed far inland, along with baleen (whalebone) and driftwood, suggesting that flooding may have been yet another source of population loss. Steller suggested that regular flooding events hit Bering Island, indicated by the shape of its mountains which were likely eroded by waves. The particular flooding event noted by Steller seems to have occurred in 1738.
A number of sea cow sightings were reported after 1768, the official date of extinction. According to Lucien Turner, an American ethnologist and naturalist, the natives of Attu Island reported that the sea cows survived into the 1800s, and were sometimes hunted. Another sighting after 1768 was made by a passenger on board the Kruzenshtern's world voyage between 1803 and 1806, near the Nordenskiöld Archipelago.
In 1962 the whaling ship Buran reported a group of large marine mammals grazing on seaweed in shallow water off of Kamchatka in the Gulf of Anadyr. The crew reported seeing six of these animals ranging from 6 to 8 metres (20 to 26 ft), with trunks and split lips. In 1963 the official journal of the USSR's Academy of Sciences published an article reporting a possible sighting. There have also been alleged sightings by local fishermen in the northern Kuril Islands, and around the Kamchatka and Chukchi peninsulas. These sightings may have been mistaken identifications of extant arctic marine mammals such as the narwhal (Monodon monoceros) and the Northern elephant seal (Mirounga angustirostris).
Steller's sea cow was described as being "tasty" by Steller; the meat was said to have a similar taste to corned beef, though it was tougher, redder, and needed to be cooked for longer. Due to the sea cow's size, the meat was plentiful, and it lasted a long time, perhaps due the high amount of salt in the animal's diet. This delayed spoiling to some extent, with the salt effectively curing it. The sea cow's fat could be used for cooking, as an odorless lamp oil, and apparently even as a laxative. The thick, sweet milk of female sea cows could be drunk or made into butter, and the thick, leathery hide could be used to make clothing such as shoes and belts.
Towards the end of the 1800s, bones and fossils from Steller's sea cow specimens were valuable and could be sold to museums for high prices; however, demand died down in the 1900s. Steller's sea cow bones are still sold commercially, though they are unlikely to be authentic and likely belong to arctic cetaceans. The highly dense cortical bones of Steller's sea cows are well suited material for decorative items such as knife handles and other carvings. As the sea cow is extinct, this "mermaid ivory" does not fall under the jurisdiction of the Marine Mammal Protection Act (MMPA) or the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which restrict the trade of marine mammal products. Because of this the distribution is legal, though the sale of unfossilized bones is generally prohibited. In Alaska, however, native artisan products made from these bones are legal to sell in the United States. As some the material is not actually from Steller's sea cows, the trade is regulated.
Portrayals in media
Tales of a Sea Cow is a 2012 film by Icelandic-French artist Etienne de France "documenting" a fictional 2006 re-discovery of a population of Steller's sea cows off the coast of Greenland. The film has been exhibited in art museums and universities in Europe.
Steller's sea cows appear in two books of poetry: Nach der Natur (1995) by Winfried Georg Sebald, and Species Evanescens (2009) by Russian poet Andrei Bronnikov. Bronnikov's book depicts the events of the Great Northern Expedition through the eyes of Steller, while Sebald's book looks at the conflict between man and nature, including the extinction of Steller's sea cow.
- Holocene extinction
- List of extinct animals of North America
- List of Asian animals extinct in the Holocene
- List of recently extinct mammals
- Evolution of sirenians
- Cuesta sea cow
- Takikawa sea cow
- Stejneger, L. H. (1936). Georg Wilhelm Steller, the Pioneer of Alaskan Natural History. Cambridge, Massachusetts: Harvard University Press. pp. 1–623. ISBN 978-0-576-29124-8. OCLC 836920902.
- Domning, D.; Anderson, P.K.; Turvey, S. (2008). "Hydrodamalis gigas". IUCN Red List of Threatened Species. Version 2008. International Union for Conservation of Nature. Retrieved 19 August 2016.
- Wilson, D.E.; Reeder, D.M., eds. (2005). "Hydrodamalis". Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 92. ISBN 978-0-8018-8221-0. OCLC 62265494.
- Wilson, D.E.; Reeder, D.M., eds. (2005). "Hydrodamalis gigas". Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 92. ISBN 978-0-8018-8221-0. OCLC 62265494.
- Palmer, Theodore S. (1895). "The Earliest Name for Steller's sea cow and Dugong". Science. 2 (40): 449–450. PMID 17759916. doi:10.1126/science.2.40.449-a.
- Forsten, Ann; Youngman, Phillip (1982). "Hydrodamalis gigas" (PDF). Mammal Species (165): 1–3. JSTOR 3503855. doi:10.2307/3503855.
- Marsh, Helene; O'Shea, Thomas J.; Reynolds III, John E. (2011). "Steller's sea cow: discovery, biology and exploitation of a relict giant sirenian". Ecology and Conservation of the Sirenia: Dugongs and Manatees. New York, New York: Cambridge University Press. pp. 18–35. ISBN 978-0-521-88828-8. OCLC 778803577.
- Scheffer, Victor B. (November 1972). "The Weight of the Steller Sea Cow". Journal of Mammalogy. 53 (4): 912–914. JSTOR 1379236. doi:10.2307/1379236.
- Turvey, S. T.; Risley, C. L. (2006). "Modelling the extinction of Steller's sea cow". Biology Letters. 2 (1): 94–7. PMC . PMID 17148336. doi:10.1098/rsbl.2005.0415.
- Whitmore Jr., Frank C.; Gard, Jr., L. M. (1977). "Steller's Sea Cow (Hydrodamalis gigas) of Late Pleistocene Age from Amchitka, Aleutian Islands, Alaska" (PDF). Geological Survey Professional Paper. Washington, D. C.: United States Government Printing Office. 1036.
- Mattioli, Stefano; Domning, Daryl P. (2006). "An Annotated List of Extant Skeletal Material of Steller's Sea Cow (Hydrodamalis gigas) (Sirenia: Dugongidae) from the Commander Islands". Aquatic Mammals. 32 (3): 273–288. doi:10.1578/AM.32.3.2006.273.
- Berta, Annalisa (2012). Return to the Sea: The Life and Evolutionary Times of Marine Mammals. Berkeley, California: University of California Press. p. 131. ISBN 978-0-520-27057-2. OCLC 757476446.
- Steller, Georg W. (2011) . "The Manatee". In Miller, Walter. De Bestiis Marinis. Lincoln, Nebraska: University of Nebraska. pp. 13–43. ISBN 978-1-295-08525-5. OCLC 867637409.
- Anderson, P. K.; Domning, D. P. (2008). Perrin, William F.; Wursig, Bernd; Thewissen, J. G. M., eds. Encyclopedia of Marine Mammals (2nd ed.). San Diego, California: Academic Press. pp. 1104–1106. ISBN 978-0-12-373553-9. OCLC 262718627.
- Berta, A.; Sumich, J. L.; Kovacs, K. M. (2015). "Sirenians". Marine Mammals: Evolutionary Biology (3rd ed.). Boston, Massachusetts: Academic Press. p. 249. ISBN 978-0-12-397002-2. OCLC 953575838.
- Takahashi, S.; Domning, D. P.; Saito, T. (1986). "Dusisiren dewana, n. sp. (Mammalia: Sirenia), a new ancestor of Steller’s sea cow from the upper Miocene of Yamagata Prefecture, northeastern Japan". Transactions and Proceedings of the Paleontological Society of Japan, New Series (141): 296–321.
- Loker, Eric; Hofkin, Bruce (2015). Parasitology: A Conceptual Approach. New York, New York: Taylor and Francis Group. p. 293. ISBN 978-0-8153-4473-5. OCLC 929783662.
- Estes, James A.; Burdin, Alexander; Doak, Daniel F. (2016). "Sea otters, kelp forests, and the extinction of Steller's sea cow". Proceedings of the National Academy of Sciences of the United States of America. 113 (4): 880–885. Bibcode:2016PNAS..113..880E. PMC . PMID 26504217. doi:10.1073/pnas.1502552112.
- Springer, M.; Signore, A. V.; Paijmans, J. L. A.; Vélez-Juarbe, J.; Domning, D. P.; Bauer, C. E.; He, K.; Crerar, L.; Campos, P. F.; Murphy, W. J.; Meredith, R. W.; Gatesy, J.; Willerslev, E.; MacPhee, R. D.; Hofreiter, M.; Campbell, K. L. (2015). "Interordinal gene capture, the phylogenetic position of Steller’s sea cow based on molecular and morphological data, and the macroevolutionary history of Sirenia". Molecular Phylogenetics and Evolution. 91 (10): 178–193. PMID 26050523. doi:10.1016/j.ympev.2015.05.022.
- Furusawa, Hitoshi (2004). "A phylogeny of the North Pacific Sirenia (Dugongidae: Hydrodamalinae) based on a comparative study of endocranial casts". Paleontological Research. 8 (2): 91–98. doi:10.2517/prpsj.8.91.
- Domning, D. P. (1978). Sirenian evolution in the North Pacific Ocean. 118. Berkeley, California: University of California Publications in Geological Sciences. pp. 1–176. ISBN 978-0-520-09581-6. OCLC 895212825.
- Hydrodamalinae at fossilworks.org (retrieved 12 March 2017)
- Marsh, Helene. "Chapter 57: Dugongidae". Fauna of Australia (PDF). 1B. Canberra, Australia: CSIRO. ISBN 978-0-644-06056-1. OCLC 27492815.
- Domning, Daryl P. (1978). "An Ecological Model for Late Tertiary Sirenian Evolution in the North Pacific Ocean". Systematic Zoology. 25 (4): 352–362. JSTOR 2412510.
- Steller, G. W. (1988). Frost, O. W., ed. Journal of a Voyage with Bering, 1741–1742. Translated by Engel, M. A.; Frost, O. W. Stanford, California: Stanford University Press. ISBN 978-0-8047-2181-3. OCLC 877954975.
- Frost, Orcutt William (2003). "Shipwreck and Survival". Bering: The Russian Discovery of America. New Haven, Connecticut: Yale University Press. pp. 262–264. ISBN 978-0-300-10059-4. OCLC 851981991.
- Buechner, E. (1891). "Nordischen Seekuh". Memoirs of the Imperial Academy of St. Petersburg Science (in German). 38 (7): 1–24.
- Domning, Daryl P.; Thomason, James; Corbett, Debra G. (2007). "Steller's sea cow in the Aleutian Islands". Marine Mammal Science. 23 (4): 976–983. doi:10.1111/j.1748-7692.2007.00153.x.
- Crerar, Lorelei D.; Crerar, Andrew P.; Domning, Daryl P.; Parsons, E. C. M. (2014). "Rewriting the history of an extinction—was a population of Steller's sea cows (Hydrodamalis gigas) at St Lawrence Island also driven to extinction?" (PDF). Biology Letters. 10 (11): 20140878. PMC . PMID 25428930. doi:10.1098/rsbl.2014.0878.
- Derbeneva, Olga A.; Sukernik, Rem I.; Volodko, Natalia V.; Hosseini, Seyed H.; Lott, Marie T.; Wallace, Douglas C. (2002). "Analysis of Mitochondrial DNA Diversity in the Aleuts of the Commander Islands and Its Implications for the Genetic History of Beringia". American Journal of Human Genetics. 71 (2): 415–421. PMC . PMID 12082644. doi:10.1086/341720.
- Anderson, Paul K. (July 1995). "Competition, Predation, and the Evolution and Extinction of Steller's Sea Cow, Hydrodamalis gigas". Marine Mammal Science. Society for Marine Mammalogy. 11 (3): 391–394. doi:10.1111/j.1748-7692.1995.tb00294.x.
- MacDonald, Stephen O.; Cook, Joseph A. (2009). Recent Mammals of Alaska. Fairbanks, Alaska: University of Alaska Press. pp. 57–58. ISBN 978-1-60223-047-7. OCLC 488523994.
- Corbett, D. G.; Causey, D.; Clemente, M.; Koch, P. L.; Doroff, A.; Lefavre, C.; West, D. (2008). "Aleut Hunters, Sea Otters, and Sea Cows". Human Impacts on Ancient Marine Ecosystems. University of California Press. pp. 43–76. ISBN 978-0-520-93429-0. JSTOR 10.1525/j.ctt1pphh3. OCLC 929645577.
- Savinetsky, A. B.; Kiseleva, N. K.; Khassanov, B. F. (2004). "Dynamics of sea mammaland bird populations of the Bering Sea region over the last several millennia". Palaeogeography, Palaeoclimatology, Palaeoecology. 209 (1–4): 335–352. doi:10.1016/j.palaeo.2004.02.009.
- Haycox, Stephen W. (2002). Alaska: An American Colony. Seattle, Washington: University of Washington Press. pp. 55, 144. ISBN 978-0-295-98249-6. OCLC 49225731.
- Jones, Ryan T. (September 2011). "A 'Havock Made among Them': Animals, Empire, and Extinction in the Russian North Pacific, 1741–1810". Environmental History. 16 (4): 585–609. JSTOR 23049853. doi:10.1093/envhis/emr091.
- Ellis, Richard (2004). No Turning Back: The Life and Death of Animal Species. New York, New York: Harper Perennial. p. 134. ISBN 978-0-06-055804-8. OCLC 961898476.
- Steller, G. W. (1925). Golder, F. A., ed. Steller's Journal of the Sea Voyage from Kamchatka to America and Return on the Second Expedition, 1741-1742 (PDF). Bering's Voyages: An Account of the Efforts of the Russians to Determine the Relation of Asia and America. 2. Translated by Stejneger, L. New York, New York: American Geographical Society. p. 207.
- Eberhart, G. H. (2002). Mysterious Creatures: A Guide to Cryptozoology. Santa Barbara, California: ABC-CLIO. p. 519. ISBN 978-1-57607-283-7. OCLC 50562074.
- Berzin, A. A.; Tikhomirov, E. A.; Troinin, V. I. (2007) . Translated by Ricker, W. E.. "Ischezla li Stellerova korova?" [Was Steller's sea cow exterminated?] (PDF). Priroda. 52 (8): 73–75.
- Bertram, C.; Bertram, K. (1964). "Does the "extinct" sea cow survive?". New Scientist. 24 (415): 313.
- Silverberg, R. (1973). The Dodo, the Auk and the Oryx. London, United Kingdom: Puffin Books. p. 83. ISBN 978-0-14-030619-4. OCLC 473809649.
- Crerar, L. D.; Freeman, E. W.; Domning, D. P.; Parsons, E. C. M. (2017). "Illegal Trade of Marine Mammal Bone Exposed: Simple Test Identifies Bones of "Mermaid Ivory" or Steller's Sea Cow (Hydrodamalis gigas)". Frontiers in Marine Science. 3 (272). doi:10.3389/fmars.2016.00272.
- Kipling, Rudyard (1894). "The White Seal". The Jungle Books. ISBN 978-0-585-00499-0. OCLC 883570362.
- Kipling, Rudyard (2013) . Nagai, Kaori, ed. The Jungle Books. Penguin UK. p. 405. ISBN 978-0-14-196839-1. OCLC 851153394.
- "Tales of a Sea Cow (2012)". IMDb. Retrieved 20 January 2017.
- "Etienne de France, "Tales of a Sea Cow" — Exhibition at Parco Arte Vivente, Torino, Italy". alan-shapiro.com.
- Bureaud, Annick. "Tales of a Sea Cow: A Fabulatory Science Story" (PDF). Retrieved August 19, 2016.
- Species Evanescens (Russian Edition). Amazon.com. ASIN 9079625027.
- Bronnikov, Andrei (2009). Species Evanescens (in Russian). Reflections. ISBN 978-90-79625-02-4. OCLC 676724013.
- Sebald, W. G. "Nach der Natur Sebald" (in German). Hanser Literaturverlage. Retrieved 19 January 2017.
|Wikimedia Commons has media related to Hydrodamalis gigas.|
|Wikispecies has information related to: Hydrodamalis gigas|