Editing Baikal seal (section)

==Description==
[[File:Baikal-seal 4747-pho.jpg|thumb|A young seal]]
The Baikal seal is one of the smallest true seals. Adults typically grow to {{convert|1.1-1.4|m|ftin|abbr=on}} in length<ref name="iucn status 12 November 2021" /> with a body mass from {{convert|abbr=on|63|to|70|kg|lb}}.<ref name=SCS>{{cite web|url=http://www.pinnipeds.org/species/baikal.htm |title=Baikal Seal (Phoca Sibirica) |publisher=Seal Conservation Society |access-date=2007-09-27 |archive-url=https://web.archive.org/web/20071006193844/http://www.pinnipeds.org/species/baikal.htm |archive-date=6 October 2007 |url-status=dead }}</ref> The maximum reported size is {{convert|1.65|m|ftin|abbr=on}} in length and {{convert|130|kg|lb|abbr=on}} in weight.<ref name=zooex>{{cite web| title=Baikal seal | url=http://baikal.ru/en/baikal/excursion/nerpa.html | publisher=baikal.ru | access-date=1 June 2017}}</ref> There are significant annual variations in the weight, with lowest weight in the spring and highest weight, about 38–42% more, in the fall.<ref name=Pastukhov>{{cite web| url=http://www.bww.irk.ru/baikalseals/baikalseals_01.html| title=The Face of Baikal – Nerpa| author=Pastukhov, Vladimir D.| publisher=Baikal Web World| access-date=2007-09-27| archive-url= https://web.archive.org/web/20071025051137/http://www.bww.irk.ru/baikalseals/baikalseals_01.html| archive-date= 25 October 2007 | url-status= live}}</ref> The animals show very little [[sexual dimorphism]]; males are only slightly larger than females.<ref name=SCS/> They have a uniform, [[Steel (color)|steely]]-grey coat on their backs and fur with a yellowish tinge on their abdomens. As the coat weathers, it becomes brownish.<ref name=Pastukhov/> When born, the pups weigh {{convert|3-3.5|kg|lb|abbr=on}} and are about {{convert|70|cm|ftin|abbr=on}} long.<ref name="iucn status 12 November 2021" /> They have coats of white, silky, natal fur. This fur is quickly shed and exchanged for a darker coat, much like that of adults. Rarely, Baikal seals can be found with spotted coats.<ref name=SCS/>
===Evolution===
The skull structure of the Baikal seal suggests it is closely related to the [[Caspian seal]]. In addition, the morphological structures in both species suggest they are descended from Arctic [[ringed seal]]s.<ref>{{cite journal|last1=Endo|first1=H.|last2=Sakata|first2=S.|last3=Arai|first3=T.|last4=Miyazaki|first4=N.|title=The Muscles of Mastication in the Caspian Seal (''Phoca caspica'')|journal= Anatomia, Histologia, Embryologia|date=April 2001|volume= 31|issue= 5|pages=262–265|doi=10.1046/j.1439-0264.2002.00372.x|pmid=12484416|s2cid=30684638}}</ref> In prehistory, they may have swum up rivers and streams, or there is the possibility that Lake Baikal was linked to the ocean at some point through a large body of water, such as the [[Paratethys Sea]], [[West Siberian Glacial Lake]] or [[West Siberian Plain]], formed in a previous [[ice age]]. The seals are estimated to have inhabited Lake Baikal for some two million years.<ref>{{cite journal |last1=Palo |first1=Jukka U. |last2=Väinölä |first2=Risto |title=The enigma of the landlocked Baikal and Caspian seals addressed through phylogeny of phocine mitochondrial sequences|journal=Biological Journal of the Linnean Society |date=2006 |volume=88 |issue=1 |pages=61–72 |doi=10.1111/j.1095-8312.2006.00607.x|doi-access=free}}</ref>