{{Short description|Exctinct genus of marine mammal}} {{Automatic taxobox | taxon = Behemotops | fossil_range = {{Fossil range|Oligocene}} | image = Behemotops.jpg | image2 = Behemotops proteus Wikipedia Juandertal.jpg | authority = {{Harvnb|Domning|Ray|McKenna|1986}} | type_species = * {{Extinct}}'''''Behemotops proteus''''' <br /><small>{{Harvnb|Domning|Ray|McKenna|1986}}</small> | subdivision_ranks = Other species | subdivision_ref = <ref name="Paeodb-36956">{{Paleodb|36956|Behemotops}}. Retrieved June 2013.</ref> | subdivision = * {{Extinct}}'''''B. katsuiei''''' <br /><small>{{Harvnb|Inuzuka|2000}}</small> }}
'''''Behemotops''''' (from the Biblical monster Behemoth, by Linnaeus and others believed to be a hippo)<ref>{{Harvnb|Domning|Ray|McKenna|1986|p=6}}</ref> is an extinct genus of herbivorous marine mammal. It lived from the Early Oligocene (Rupelian) through the Late Oligocene (33.9 mya—23 Mya), existing for approximately {{Mya|33.9-23|million years}}. It is the most primitive known desmostylian, believed to be close to the ancestry of all other desmostylians.
==Description== In comparison with later known desmostylians, ''Behemotops'' had more elephantine tooth and jaw features. It had cusped molars that more resembled those of mastodons or other land ungulates than those of later ''Desmostylus'', which exhibited odd "bound-pillar" shaped molars which may have evolved in response to the grit from a diet of sea-grass. Discovery of ''Behemotops'' helped place desmostylians as more closely related to proboscideans than sirenians, although relationships of this group are still poorly resolved.<ref name="Wallace-2007">{{Harvnb|Wallace|2007|pp=66–7}}</ref><!-- ref for para -->
''B. proteus'' was larger than ''Desmostylus'', measuring {{cvt|323|cm|ft}} in length, {{cvt|120|cm|ft}} in height and {{convert|1979|kg|lbs}} in body mass.<ref>Inuzuka, N. (1996). Body size and mass estimates of desmostylians(Mammalia). The Journal of the Geological Society of Japan, 102(9), 816–819. https://doi.org/10.5575/geosoc.102.816</ref> ''B. katsuiei'' had an estimated body length of {{Convert|290|cm|abbr=on}},<ref>{{Harvnb|Hayashi|Houssaye|Nakajima|Kentaro|2013|loc=Materials and Methods}}</ref> making it the smaller of the two species.<ref name="JVP-2009" />
===Formerly placed in ''Behemotops''=== ''Behemotops emlongi'', also described in 1986, was placed in the synonymy of ''B. proteus'' in 1994,<ref name="Ray 1994 205">{{Harvnb|Ray|Domning|McKenna|1994|p=205}}</ref> but was later placed in its own genus, ''Seuku'', in 2014.<ref>{{cite journal|doi=10.1080/02724634.2015.979939 | volume=35 | title=New insights on the most primitive desmostylian from a partial skeleton of Behemotops (Desmostylia, Mammalia) from Vancouver Island, British Columbia | journal=Journal of Vertebrate Paleontology | year=2015 | article-number=e979939| last1=Beatty | first1=Brian Lee | last2=Cockburn | first2=Thomas C. | issue=5 | bibcode=2015JVPal..35E9939B | s2cid=129905948 }}</ref> The first specimen, USNM 186889, a massive tusk in fragments of a mandible — was found in Lincoln County, Oregon ({{Coord|44|29|50|N|124|05|00|W|display=inline}})<ref>{{Harvnb|Domning|Ray|McKenna|1986|p=23}}</ref> in 1969. In 1977, at the same location, fossil collector Douglas Emlong discovered a poorly preserved half right mandible — USNM 244033 — matching the first specimen. This mandible became the holotype of ''Seuku emlongi'' (then described as ''B. emlongi'') when described by {{Harvnb|Domning|Ray|McKenna|1986}}.<ref name="Ray-etal-1994">{{Harvnb|Ray|Domning|McKenna|1994|loc=Japanese ''Behemotops'', p. 217}}</ref> ''B. emlongi'' was later eventually made a synonym of ''B. proteus'' in 1994,<ref name="Ray 1994 205" /> before being removed from the genus altogether. ==History of discovery== ===''B. proteus''=== In 1976, Emlong discovered a juvenile mandible — USNM 244035 — on Olympic Peninsula, Clallam County, Washington ({{Coord|48.2|-123.9|display=inline}}, paleocoordinates {{Coord|47.8|-115.0|display=inline}})<ref>{{Paleodb|collection|45809|LACMVP 5412 (Oligocene of the United States)}}. Retrieved June 2013.</ref> which {{Harvnb|Domning|Ray|McKenna|1986}} made the holotype of ''B. proteus''. Teeth of a young adult — LACM 124106 – was found in the same rock unit in 1986.<ref name="Ray-etal-1994" />
More complete material of ''B. proteus'' was found on Vancouver Island, British Columbia in 2007: the left side of an entire skull with several teeth, a partial scapula, an almost complete humerus, and several ribs and vertebrae. The cranial features of this specimen were similar to those of ''Cornwallius'', from which {{Harvnb|Cockburn|Beatty|2009}} concluded that Desmostylidae and Paleoparadoxiidae probably diverged earlier than previously believed. Cockburn and Beatty also noted that, in their specimen, all teeth have erupted but the epiphyses of the bones are unfused and that it probably was an subadult; from which they concluded that the adult dentition was not delayed in ''Behemotops'', unlike ''Desmostylus'' and other Afrotheria, and that delayed dentition can not be the most primitive state of Desmostylia.<ref name="JVP-2009">{{Harvnb|Cockburn|Beatty|2009|loc=Abstract}}</ref>
===''B. katsuiei''=== Skeletons of several individuals were found on western Hokkaido Island in Japan ({{Coord|43.3|143.8|display=inline}}: paleocoordinates {{Coord|44.6|141.4|display=inline}})<ref>{{Paleodb|collection|45786|Morawan (Upper tuffaceous Siltstone Member) (Oligocene of Japan)}}. Retrieved June 2013.</ref> in 1976, but this material remained unknown outside Japan until they were described in 1987.<ref name="Ray-etal-1994" /> They were first assumed to be early Miocene in age, but a new analysis of the site in the mid-1980s revised their age to the Oligocene; making them the oldest found on the Japanese island, ancestral to all other desmostylians. They were later included into the genus ''Behemotops'' proposed by Domning et al. 1986.<ref>{{Harvnb|Saito|Barron|Sakamoto|1988}}</ref>
==Notes== {{Reflist|30em}}
==References== {{Refbegin|30em}} * {{Cite journal | last1 = Cockburn | first1 = Thomas | last2 = Beatty | first2 = Brian | title = A Partial Skeleton of ''Behemotops'' (Desmostylia, Mammalia) from Vancouver Island, British Columbia | year = 2009 | journal = Journal of Vertebrate Paleontology | volume = 29 | issue = 3, Supplement | url = http://www.aragosaurus.com/secciones/publicaciones/artic/Company_etal_2009c_1.pdf | access-date = March 24, 2018 | doi = 10.1080/02724634.2009.10411818 | pages=1A–211A}}<!-- {{Harvnb|Cockburn|Beatty|2009}} --> * {{Cite book | last1 = Domning | first1 = Daryl P. | last2 = Ray | first2 = Clayton Edward | last3 = McKenna | first3 = Malcolm C. | author3-link = Malcolm C. McKenna | title = Two new Oligocene desmostylians and a discussion of Tethytherian systematics | year = 1986 | series = Smithsonian Contributions to Paleobiology | volume = 59 | pages = 1–56 | url = http://www.sil.si.edu/SmithsonianContributions/Paleobiology/pdf_lo/SCtP-0059.pdf | access-date = March 24, 2018 | oclc = 489725338 | lccn = 85600322 }}<!-- {{Harvnb|Domning|Ray|McKenna|1986}} --> * {{Cite journal | last1 = Hayashi | first1 = Shoji | last2 = Houssaye | first2 = Alexandra | last3 = Nakajima | first3 = Yasuhisa | last4 = Kentaro | first4 = Chiba | author5 = Ando, Tatsuro |author6=Sawamura, Hiroshi |author7=Inuzuka, Norihisa |author8=Kaneko, Naotomo |author9=Osaki, Tomohiro | title = Bone Inner Structure Suggests Increasing Aquatic Adaptations in Desmostylia (Mammalia, Afrotheria) | year = 2013 | journal = PLOS ONE | volume = 8 | issue = 4 | article-number = e59146 | doi = 10.1371/journal.pone.0059146 | oclc = 837402105 | pmid=23565143 | pmc=3615000| doi-access = free | bibcode = 2013PLoSO...859146H }}<!-- {{Harvnb|Hayashi|Houssaye|Nakajima|Kentaro|2013}} --> * {{Cite journal | last = Inuzuka | first = Norihisa | title = Primitive Late Oligocene desmostylians from Japan and phylogeny of the Desmostylia | year = 2000 | journal = Bulletin of Ashoro Museum of Paleontology | volume = 1 | pages = 91–123 }}<!-- {{Harvnb|Inuzuka|2000}} --> * {{Cite book | last1 = Ray | first1 = Clayton E. | last2 = Domning | first2 = Daryl P. | last3 = McKenna | first3 = Malcolm C. | chapter = A new specimen of Behemotops proteus (Order Desmostylia) from the marine Oligocene of Washington | chapter-url = https://www.biodiversitylibrary.org/item/21705#page/215/mode/1up | access-date = March 24, 2018 | editor1-last = Berta | editor1-first = A. | editor2-last = Deméré | editor2-first = T. A. | year = 1994 | title = Proceedings of the San Diego Society of Natural History | volume = 29 | pages = 205–22 }}<!-- {{Harvnb|Ray|Domning|McKenna|1994}} --> * {{Cite journal | last1 = Saito | first1 = Tsunemasa | last2 = Barron | first2 = John A | last3 = Sakamoto | first3 = Masamichi | title = An early late Oligocene age indicated by diatoms for a primitive desmostylian mammal Behemotops from eastern Hokkaido, Japan. | year = 1988 | journal = Proceedings of the Japan Academy | series = B: Physical and Biological Sciences | volume = 64 | issue = 9 | pages = 269–73 | url = https://www.jstage.jst.go.jp/article/pjab1977/64/9/64_9_269/_pdf | access-date = March 24, 2018 | doi = 10.2183/pjab.64.269 | oclc = 4639400119 | doi-access = free | bibcode = 1988PJAB...64..269S }}<!-- {{Harvnb|Saito|Barron|Sakamoto|1988}} --> * {{Cite book | last = Wallace | first = David Rains | author-link = David Rains Wallace | title = Neptune's Ark: From Ichthyosaurs to Orcas | year = 2007 | publisher = University of California Press | url = https://books.google.com/books?id=M9nPQonygUsC&pg=PA66 | access-date = March 24, 2018 | isbn = 978-0-520-24322-4 }}<!-- {{Harvnb|Wallace|2007}} --> {{Refend}}
{{Paenungulata}} {{Taxonbar|from=Q4880763}}
Category:Desmostylians Category:Oligocene mammals of Asia Category:Oligocene mammals of North America Category:Rupelian genus first appearances Category:Chattian genus extinctions Category:Prehistoric placental genera Category:Fossil taxa described in 1986 Category:Fossils of Japan