Pontolis

{{Short description|Extinct genus of carnivores}} {{Use dmy dates|date=May 2026}} {{Automatic taxobox | fossil_range = {{Geological range|11.608|5.332|[[Miocene]]-[[Pliocene]]}} | image = Pontolis barroni LACM.jpg | image_caption = Skull (LACM 162551) of ''P. barroni'', [[Natural History Museum of Los Angeles County]] | taxon = Pontolis | authority = [[Frederick W. True|True]], 1905 | type_species = {{extinct}}'''''Pontolis magnus''''' | type_species_authority = [[Frederick W. True|True]], 1905 | subdivision_ranks = Species | subdivision = *{{extinct}}'''''P. magnus''''' (True, 1905, [[type species|type]]] *{{extinct}}'''''P. barroni''''' Biewer, Velez-Juarbe & Parham, 2020 *{{extinct}}'''''P. kohnoi''''' Biewer, Velez-Juarbe & Parham, 2020 | synonyms = ''Pontoleon magnus'' True, 1905 }}

'''''Pontolis''''' is an extinct genus of large [[walrus]]. It contained three species, '''''P. magnus''''', '''''P. barroni''''', and '''''P. kohnoi'''''.<ref name="Pontolis">{{cite web |url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=36942 |title=Pontolis |website=[[Fossilworks]] |access-date=17 December 2021 }}</ref><ref>{{Cite journal|last1=Biewer|first1=Jacob N.|last2=Velez-Juarbe|first2=Jorge|last3=Parham|first3=James F.|date=2020-12-01|title=Insights on the Dental Evolution of Walruses Based on New Fossil Specimens from California|journal=Journal of Vertebrate Paleontology|volume=40|issue=5|article-number=e1833896|doi=10.1080/02724634.2020.1833896|bibcode=2020JVPal..40E3896B |s2cid=228814992 |issn=0272-4634}}</ref> Like all [[pinniped]]s, ''Pontolis'' was a heavily built amphibious carnivore. ''Pontolis'' lived along the Pacific coast of North America along what is now the western coasts of [[California]] and [[Oregon]] between 11.608 and 5.332 million years ago, during the [[Miocene]] and [[Pliocene]].<ref name="Pontolis" />

== Description == [[File:Pontolis magnus.jpg|left|thumb|215x215px|Jaw of ''P. magnus'']] The skull of ''Pontolis'' is {{cvt|60|cm}} long, surpassing skulls of any other prehistoric pinnipeds and twice as big as the skulls of modern male walruses.<ref name=Berta2017> {{cite book | url = https://books.google.com/books?id=mHw6DwAAQBAJ&dq=Gomphotaria+skull+47+cm&pg=PA110 | title = The Rise of Marine Mammals: 50 Million Years of Evolution | publisher = Johns Hopkins University Press | date = 2017 | access-date = 2022-08-21 | page = 110 | author = Annalisa Berta | isbn = 978-1-4214-2325-8 }}</ref> This giant species was much larger than modern walrus, though like many other extinct walrus species, its upper canines did not develop into long tusks like those of the modern walrus. ''Pontolis'' reached more than {{cvt|4|m}} in body length,<ref>Morgan Churchill, Mark T. Clementz, Naoki Kohno. "Cope's rule and the evolution of body size in Pinnipedimorpha (Mammalia: Carnivora)". Evolution. 2015 Jan;69(1):201-15. doi:10.1111/evo.12560</ref> rivaling the extant [[southern elephant seal]] as the largest pinniped<ref> {{cite book | url = https://books.google.com/books?id=DeXEDwAAQBAJ&dq=largest+pinniped+%22pontolis%22&pg=PA17 | title = The Atlantic Walrus: Multidisciplinary Insights into Human-Animal Interactions | publisher = Charlotte Cockle | date = 2021 | access-date = 2022-08-21 | page = 17 | author = Xénia Keighley, Morten Tange Olsen, Peter Jordan, Sean P.A. Desjardins | isbn = 978-0-12-817431-9 }}</ref> and member of the order [[Carnivora]] of all time. Weight estimates for ''Pontolis'' range between {{convert|2000|to|4000|kg|lb|abbr=on}}.<ref>Valentin, T. ''Encyclopedia Largest Prehistoric Animals Vol.1 Vertebrates part1 Mammals ch.1 Carnivores - Hyaenidae, Mustelids and Viverrids Encyclopedia Largest prehistoric animals Vol.1 Vertebrates part1 Mammals ch.1 Carnivores -Mesonychids.''</ref>

==References== {{Reflist}}

[[Category:Miocene pinnipeds]] [[Category:Fossil taxa described in 1905]] [[Category:Prehistoric pinnipeds of North America]] [[Category:Odobenidae]] [[Category:Prehistoric carnivoran genera]]