Editing Steller's sea cow (section)

==Taxonomy==
===Phylogeny===
{{Multiple image|image1=Dugong dugon.jpg|image2=Dugong Marsa Alam PLW edit.jpg|alt1=A gray dugong swimming in the water: The underside is visible, and it has large limbs behind the head, pointed down. They are triangular in shape, similar to a dolphin fin. It has a thin body compared to the head, and a forked tail fluke like that of a dolphin. It has a small eye.|alt2=A gray dugong bottom feeding, with plumes of sand trailing from it mouth. It is resting its hands on the ground. Small sprouts of seagrasses litter on the ground, and yellow fish with black stripes are hovering around its snout. The snout has two large nostrils, and the mouth is on the ground.|direction=vertical|align=left|footer=The closely related [[dugong]]}}

Steller's sea cow was a member of the [[genus (biology)|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 [[mangrove]]s before adapting to the cold climates of the [[Pacific Ocean|North Pacific]].<ref>{{cite book |last=Domning |first=D. P. |year=1978 |title=Sirenian evolution in the North Pacific Ocean |publisher=University of California Publications in Geological Sciences |location=Berkeley, California |isbn=978-0-520-09581-6 |oclc=895212825 |volume=118 |pages=1–176}}</ref> ''Hydrodamalis'' and ''Dusisiren'' are classified together in the [[family (biology)|subfamily]] [[Hydrodamalinae]],<ref>{{fossilworks|id=53133|title=Hydrodamalinae|date=12 March 2017}}</ref> which diverged from other sirenians around 4 to 8 [[mya (unit)|mya]].<ref>{{cite journal |last1=Rainey |first1=W. E. |last2=Lowenstein |first2=J. M. |last3=Sarich |first3=V. M. |last4=Magor |first4=D. M. |year=1984 |title=Sirenian molecular systematics—including the extinct Steller's sea cow (''Hydrodamalis gigas'') |journal=[[Naturwissenschaften]] |doi=10.1007/BF01189187 |pmid=6521758 |volume=71 |issue=11 |pages=586–588|bibcode=1984NW.....71..586R |s2cid=28213762 }}</ref> Steller's sea cow is a member of the family [[Dugongidae]], the sole surviving member of which, and thus Steller's sea cow's closest living relative is the [[dugong]] (''Dugong dugon'').<ref>{{cite book |last=Marsh |first=Helene |title=Fauna of Australia |chapter=Chapter 57: Dugongidae |publisher=[[CSIRO]] |location=Canberra, Australia |isbn=978-0-644-06056-1 |oclc=27492815 |volume=1B |chapter-url=http://www.environment.gov.au/biodiversity/abrs/publications/fauna-of-australia/pubs/volume1b/57-ind.pdf  |archive-url=https://web.archive.org/web/20130511221756/http://www.environment.gov.au/biodiversity/abrs/publications/fauna-of-australia/pubs/volume1b/57-ind.pdf |archive-date=2013-05-11 |year=1989 }}</ref>

Steller's sea cow was a direct descendant of the [[Cuesta sea cow]] (''H. cuestae''),<ref name=marsh2011/> an extinct tropical sea cow that lived off the coast of western North America, particularly California. The Cuesta sea cow is thought to have become extinct due to the onset of the [[Quaternary glaciation]] and the subsequent cooling of the oceans. Many populations died out, but the lineage of Steller's sea cow was able to adapt to the colder temperatures.<ref name=domning>{{cite journal |last=Domning |first=Daryl P. |year=1978 |title=An Ecological Model for Late Tertiary Sirenian Evolution in the North Pacific Ocean |journal=[[Systematic Biology|Systematic Zoology]] |jstor=2412510 |volume=25 |number=4 |pages=352–362 |doi=10.2307/2412510 }}</ref> 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 [[endocast]]s, the Takikawa and Steller's sea cows are more [[synapomorphy|derived]] than the Cuesta sea cow. This has led some to believe that the Takikawa sea cow is its own species.<ref name=furusawa2004/> The evolution of the genus ''Hydrodamalis'' was characterized by increased size, and a loss of teeth and [[phalanx bone|phalanges]], as a response to the onset of the Quaternary glaciation.<ref name=domning/><ref name=forsten/>

{{align|left|
Based on a 2015 study by Mark Springer:<ref>{{cite journal |last1=Springer |first1=M. |last2=Signore |first2=A. V. |last3=Paijmans |first3=J. L. A. |last4=Vélez-Juarbe |first4=J. |last5=Domning |first5=D. P. |last6=Bauer |first6=C. E. |last7=He |first7=K. |last8=Crerar |first8=L. |last9=Campos |first9=P. F. |last10=Murphy |first10=W. J. |last11=Meredith |first11=R. W. |last12=Gatesy |first12=J. |last13=Willerslev |first13=E. |last14=MacPhee |first14=R. D. |last15=Hofreiter |first15=M. |last16=Campbell |first16=K. L. |year=2015 |title=Interordinal gene capture, the phylogenetic position of Steller's sea cow based on molecular and morphological data, and the macroevolutionary history of Sirenia |journal=[[Molecular Phylogenetics and Evolution]] |doi=10.1016/j.ympev.2015.05.022 |pmid=26050523 |volume=91 |issue=10 |pages=178–193|doi-access=free |bibcode=2015MolPE..91..178S }}</ref>
{{clade|style=font-size:90%;line-height:100%;width:100%
|label1=[[Sirenia]]
|1={{clade
|1={{clade
|1={{clade
|1=†''[[Anomotherium|Anomotherium langewieschei]]''
|2=†''[[Miosiren|Miosiren kocki]]''
}}
|2={{clade
|1=[[Amazonian manatee|''Trichechus inunguis'']]
|2={{clade
|1=[[West Indian manatee|''Trichechus manatus'']]
|2=[[African manatee|''Trichechus senegalensis'']]
}}
}}
}}
|2={{clade
|1=†''[[Eotheroides|Eotheroides aegyptiacum]]''
|2={{clade
|1=†''[[Halitherium|Halitherium schinzii]]''
|2={{clade
|1=†''[[Priscosiren atlantica]]''
|2={{clade
|1=[[Dugong|''Dugong dugon'']]
}}
|3={{clade
|1=†''[[Metaxytherium|Metaxytherium krahuletzi]]''
|2={{clade
|1=†''[[Metaxytherium|Metaxytherium serresii]]''
|2=†''[[Metaxytherium|Metaxytherium medium]]''
|3=†''[[Metaxytherium|Metaxytherium floridanum]]''
|4=†''[[Metaxytherium|Metaxytherium crataegense]]''
|5={{clade
|1=†''[[Metaxytherium|Metaxytherium arctodites]]''
|2={{clade
|1=†''[[Dusisiren|Dusisiren jordani]]''
|2={{clade
|1=†''[[Cuesta sea cow|Hydrodamalis cuestae]]''
|2='''†''Hydrodamalis gigas'''''
}}
}}
}}
}}
}}
}}
}}
}}
}}
}}
}}
{{align|right|
Based on a 2004 study by Hitoshi Furusawa:<ref name=furusawa2004>{{cite journal |last=Furusawa |first=Hitoshi |year=2004 |title=A phylogeny of the North Pacific Sirenia (Dugongidae: Hydrodamalinae) based on a comparative study of endocranial casts |journal=Paleontological Research |doi=10.2517/prpsj.8.91 |volume=8 |issue=2 |pages=91–98 |s2cid=83992432 |doi-access=free |bibcode=2004PalRe...8...91F }}</ref>
{{clade|style=font-size:90%;line-height:75%
|label1=[[Sirenia]]
|1={{clade
|1=†''[[Dusisiren|Dusisiren reinharti]]''
|2={{clade
|1=†''[[Dusisiren|Dusisiren jordani]]''
|2={{clade
|1=†''[[Dusisiren|Dusisiren dewana]]''
|2={{clade
|1=†''[[Dusisiren|Dusisiren takasatensis]]''
|2={{clade
|1=†''[[Cuesta sea cow|Hydrodamalis cuestae]]''
|2={{clade
|1=†''[[Takikawa sea cow|Hydrodamalis spissa]]''
|2={{clade
|1='''†''Hydrodamalis gigas'''''
}}
}}
}}
}}
}}
}}
}}
}}
}}
{{clear}}

===Research history===
Steller's sea cow was discovered in 1741 by Georg Wilhelm Steller, and was named after him. Steller researched the wildlife of [[Bering Island]] while he was shipwrecked there for about a year;<ref>{{cite book |last=Steller |first=G. W. |author-link=Georg Wilhelm Steller |editor-last=Frost |editor-first=O. W. |translator1-last=Engel |translator1-first=M. A. |translator2-last=Frost |translator2-first=O. W. |year=1988 |title=Journal of a Voyage with Bering, 1741–1742 |publisher=[[Stanford University Press]] |location=Stanford, California |isbn=978-0-8047-2181-3 |oclc=877954975}}</ref> the animals on the island included [[relict (biology)|relict]] populations of sea cows, sea otters, [[Steller sea lion]]s, and [[northern fur seal]]s.<ref name=orcutt2003>{{cite book |last=Frost |first=Orcutt William |year=2003 |title=Bering: The Russian Discovery of America |chapter=Shipwreck and Survival |publisher=[[Yale University Press]] |location=New Haven, Connecticut |isbn=978-0-300-10059-4 |oclc=851981991 |pages=[https://archive.org/details/beringrussiandis0000fros/page/262 262–264] |chapter-url={{Google books|plainurl=yes|id=Eak1Ek9tg_8C|page=262}} |url=https://archive.org/details/beringrussiandis0000fros/page/262 }}</ref> As the crew hunted the animals to survive, Steller described them in detail. Steller's account was included 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 [[Saint Petersburg]]. Zoologist Eberhard von Zimmermann formally [[species description|described]] Steller's sea cow in 1780 as ''Manati gigas''. Biologist [[Anders Jahan Retzius]] in 1794 put the sea cow in the new genus ''Hydrodamalis'', with the specific name of ''stelleri'', in honor of Steller.<ref name=synonyms/> In 1811, naturalist [[Johann Karl Wilhelm Illiger]] reclassified Steller's sea cow into the genus ''Rytina'', which many writers at the time adopted. The name ''Hydrodamalis gigas'', the correct ''[[combinatio nova]]'' if a separate genus is recognised, was first used in 1895 by [[Theodore Sherman Palmer]].<ref name=forsten/>
[[File:Steller measuring a sea cow.jpg|thumb|left|[[Stejneger]]'s 1925 reconstruction of G. W. Steller measuring a sea cow in 1742|alt=An illustration of a dead Steller's sea cow on its side on a beach, with three men butchering it]] 
For decades after its discovery, no skeletal remains of a Steller's sea cow were known.<ref name=mattioli2006/> 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.<ref name=whitmore/> The first bones of a Steller's sea cow were unearthed in about 1840, over 70 years after it was presumed to have become 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 Saint Petersburg in 1857, and another nearly complete skeleton arrived in Moscow around 1860. Until recently, all the full skeletons were found during the 19th century, being the most productive period in terms of unearthed skeletal remains, from 1878 to 1883. During this time, 12 of the 22 skeletons having known dates of collection were discovered. Some authors did not believe possible the recovery of further significant skeletal material from the Commander Islands after this period, but a skeleton was found in 1983, and two zoologists collected about 90 bones in 1991.<ref name="mattioli2006" /> Only two to four skeletons of the sea cow exhibited in various museums of the world originate from a single individual.<ref>{{cite web|url=https://www.theguardian.com/science/animal-magic/2016/mar/25/stellers-sea-cow-specimen-helsinki|title=Look, no hands: Steller's sea cow|date=25 March 2016|publisher=The Guardian – Science Animal magic|access-date=3 December 2017}}</ref> It is known that [[Adolf Erik Nordenskiöld]], [[Benedykt Dybowski]], and [[Leonhard Hess Stejneger]] unearthed many skeletal remains from different individuals in the late 1800s, from which composite skeletons were assembled. As of 2006, 27 nearly complete skeletons and 62 complete skulls have been found, but most of them are assemblages of bones from two to 16 different individuals.<ref name="mattioli2006">{{cite journal |last1=Mattioli |first1=Stefano |last2=Domning |first2=Daryl P. |year=2006 |title=An Annotated List of Extant Skeletal Material of Steller's Sea Cow (''Hydrodamalis gigas'') (Sirenia: Dugongidae) from the Commander Islands |journal=Aquatic Mammals |volume=32 |issue=3 |pages=273–288 |url=https://www.researchgate.net/publication/250020407 |doi=10.1578/AM.32.3.2006.273|bibcode=2006AqMam..32..273M }}</ref>

===Illustrations===

The Pallas Picture is the only known drawing of Steller's sea cow believed to be from a complete specimen. It was published by [[Peter Simon Pallas]] in his 1840 work {{lang|it|Icones ad Zoographia Rosso-Asiatica}}. 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 crew 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 Saint Petersburg.<ref name=stejneger1936>{{cite book |last=Stejneger |first=L. H. |year=1936 |title=Georg Wilhelm Steller, the Pioneer of Alaskan Natural History |publisher=[[Harvard University Press]] |location=Cambridge, Massachusetts |isbn=978-0-576-29124-8 |oclc=836920902 |pages=1–623}}</ref><ref name=buechner/>

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 a 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. The drawing contains some inaccurate features such as the inclusion of eyelids and fingers, leading to doubt that it was drawn from a specimen.<ref name=stejneger1936/><ref name=buechner/>

[[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 a Steller 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.<ref name=stejneger1936/><ref name=buechner>{{cite journal |last=Buechner |first=E. |year=1891 |title=Nordischen Seekuh |language=de |trans-title=Nordic Seacow |journal=Memoirs of the Imperial Academy of St. Petersburg Science |volume=38 |number=7 |pages=1–24 |url=https://books.google.com/books?id=C2UhAQAAMAAJ&pg=RA6-PA0}}</ref>

{{Gallery|align=center|title=Early depictions of Steller's sea cow<ref name=stejneger1936/><ref name=buechner/>|File:Pallas Sea Cow.jpg|alt1=The body is oblong. On the left end is the head which is slightly smaller than the body, with a dot for an eye near the top. Just behind the head on the underside is an arm that bends back towards the tail. The tail is drawn sideways like that of a fish to show the knotch, and the top half of the tail is shaded darker than the bottom half.|The Pallas Picture: the only surviving drawing of Steller's sea cow by [[Friedrich Plenisner]], and possibly the only one drawn from a complete specimen (1840)|File:Chitrow - Seekuh, Seebaer und Seeloewe (Ausschnitt aus einer Karte).jpg|alt2=The Sea of Okhosk with the Kamchatka Peninsula to the left and Bering Island near the bottom. Above Bering Island and to the right of Russia are illustrations of Steller's sea cow and Steller's sea lion. For the sea cow, the body is oblong. On the left end is the head which is slightly smaller than the body, with a small eye with eyelids. Just behind the head on the underside is an arm that bends back towards the tail. The tail is drawn sideways like that of a fish to show the knotch, and the top half of the tail is shaded darker than the bottom half. For the sea lion, the back end of it is parallel to the ground, and the front end is perpendicular to the ground. The ears are thin and long. They have a thick neck, and a smashed-in face with the nose protruding. The front flipper is shaped like that of a dolphin, and drawn perpendicular to the ground, bending back towards the back-end. The back flipper is rectangular with four grooves parallel to each other on it.|The Pekarski Picture: a map of the [[Commander Islands]] including illustrations of Steller's sea cow and the [[Steller sea lion]] by a crew member of [[Vitus Bering]]'s [[Great Northern Expedition]] (1893)|File:Extanstellersseacowea.jpg|alt3=An oblong body with a small head, a hand with no visible fingers similar to a dolphin fin but pointed downward, and a tail fluke in the vertical position similar to a fish|The Ideal Image by [[Johann Friedrich von Brandt]] based on the Pallas Picture (1846)|File:Ледяной плен с. 097.png|alt4=An oblong body with a snout similar to a manatee with short hairs visible, a hand with no visible fingers similar to a dolphin fin but pointed downward, and a tail fluke in the vertical position similar to a fish|The Ideal Picture by [[Johann Friedrich von Brandt]] based on the Pallas Picture and skeletons (1868)|File:Waxell - Stellersche Seekuh.jpg|alt5=The animal is lying on the ground, a side view. It has a big head, a big eye, several vertical folds on the body, a hook-like hand, and a serrated tail fluke lying horizontally on the ground.|The Tsarskoye Selo Picture: a map of the [[Commander Islands]], including illustrations of Steller's sea cow, the [[Steller sea lion]], and the [[northern fur seal]], by [[Sven Waxell]] (1891); the tail is lying flat on the ground in perspective.|File:Hydrodamalis gigas.jpeg|alt6=Side view, a large body, a small head, a protruding snout, a small eye just behind the snout with eyelids, vertical folds on the body, and a serrated tail in a vertical position similar to a fish|The second Tsarskoye Selo Picture by Sven Waxell (1891)}}