Diferenzas entre revisións de «Erignathus barbatus»

ThereRecoñécense aredúas two recognized subspecies of this sealsubespecies:<ref name=msw3/>
*''Erignathus barbatus barbatus''
*''Erignathus barbatus nautica''
WhileAínda theque validitya ofvalidez thesedestas subspeciessubespecies hasfoi beencuestionada questioned,e andnon isestá notapoiada yetpor supporteddatos by any molecular datamoleculares,<ref name="Berta2012"/> analysisa ofanálise thedas animals'chamadas callsdos doesanimais indicateindica aunha differentiationdiferenciación betweenentre differentdistintas populationspoboacións.<ref name=Risch2006>{{cite journal | author = Risch, D. | year = 2006 | title = Vocalizations of male bearded seals, ''Erignathus barbatus'': classification and geographical variation | journal = Animal Behaviour | volume = 73 | issue = 5 | pages = 747–762 | doi = 10.1016/j.anbehav.2006.06.012|display-authors=etal}}</ref>
[[ImageFicheiro:Erignathus barbatus 1996-08-04.jpg|right|thumbminiatura]]
== EvolutionaryHistoria historyevolutiva ==
BeardedAtopáronse sealfósiles fossilsde havefoca beenbarbuda founden toestratos be as old as the early to middo [[PleistocenePlistoceno]]. Thesetemperán earlyou fossilsmedio. wereEstes foundfósiles ininiciais northernapareceron regionsen likerexións England,como AlaskaInglaterra, andAlasca e SwedenSuecia, asasí wellcomo as theno [[Northmar do SeaNorte]] ande theo [[Champlainmar Seade Champlain]].<ref name=":3">{{Cite journal|last=Harington|first=C. R.|date=March 2008|title=The Evolution of Arctic Marine Mammals|journal=Ecological Applications|language=en|volume=18|issue=sp2|pages=S23–S40|doi=10.1890/06-0624.1|issn=1051-0761}}</ref>
Bearded seals, like all true seals, belong to the family phocidae which is one of the three families in the clade pinnipedia along with [[otariidae]] and [[odobenidae]]. Pinnipeds are thought to have originated 27 to 25 million years ago during the late [[Oligocene]] period. One hypothesis for the evolution of pinnipeds is that pinnipeds are a diphyletic group and otariids and odobenids are more closely related to bears, and phocids are more closely related to mustelids like weasels. Another hypothesis suggests that pinnipeds are a monophyletic group that descended from a single ancestor. this has been more supported by phylogenetic analysis than the diphylectic hypothesis. One such study suggests that phocids are sister taxa to the common ancestor to both otariids and odobenids.<ref name=":3" />