Editing Narwhal (section)

== Taxonomy ==

The narwhal was scientifically described by [[Carl Linnaeus]] in his 1758 publication [[10th edition of Systema Naturae|''Systema Naturae'']].<ref name="Linnaeus">{{Cite book |last=Linnaeus |first=Carl |author-link=Carl Linnaeus |title=Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata |publisher=Lars Salvius |year=1758 |location=Stockholm |page=75 |language=la |chapter=''Monodon monoceros'' |chapter-url=https://gdz.sub.uni-goettingen.de/id/PPN362053006?tify=%7B%22pages%22%3A%5B78%2C79%5D%2C%22pan%22%3A%7B%22x%22%3A1.154%2C%22y%22%3A0.647%7D%2C%22view%22%3A%22scan%22%2C%22zoom%22%3A0.498%7D}}</ref> The word "narwhal" comes from the [[Old Norse]] {{Lang|non|nárhval}}, meaning 'corpse-whale', which possibly refers to the animal's grey, mottled skin and its habit of remaining motionless when at the water's surface, a behaviour known as "logging" that usually happens in the summer.<ref name="Fisheries and Oceans Canada">{{Cite web |year=2007 |title=The narwhal: unicorn of the seas |url=http://www.dfo-mpo.gc.ca/science/publications/uww-msm/pdf/narwhal-narval-eng.pdf |url-status=live |archive-url=https://web.archive.org/web/20130710194915/http://www.dfo-mpo.gc.ca/Science/publications/uww-msm/pdf/narwhal-narval-eng.pdf |archive-date=10 July 2013 |access-date=10 July 2013 |publisher=Fisheries and Oceans Canada}}</ref><ref name="WinterWhales">{{Cite book |last1=Heide-Jørgensen |first1=M. P. |title=Greenland's Winter Whales: The Beluga, the Narwhal and the Bowhead Whale |last2=Laidre |first2=K. L. |publisher=Ilinniusiorfik Undervisningsmiddelforlag, Nuuk, Greenland |year=2006 |isbn=87-7975-299-3 |pages=100–125}}</ref> The scientific name, ''Monodon monoceros'', is derived from [[Ancient Greek]], meaning 'single-tooth single-horn'.<ref>{{Cite book |last=Webster |first=Noah |title=An American Dictionary of the English Language |date=1880 |publisher=G. & C. Merriam |page=854 |chapter=Narwhal |chapter-url=https://books.google.com/books?id=7MVHakLeewQC&pg=PA854}}</ref>

The narwhal is most closely related to the [[beluga whale]] (''Delphinapterus leucas''). Together, these two species comprise the only [[Neontology|extant]] members of the family [[Monodontidae]], sometimes referred to as the "white whales".{{Citation needed|date=December 2024}} Monodontids are distinguished by their pronounced [[melon (whale)|melon]]s (acoustic sensory organs), short [[snout]]s and the absence of a true [[dorsal fin]].<ref name="EoM">{{Cite book |last=Brodie, Paul |url=https://archive.org/details/encyclopediaofma00mals_0/page/200 |title=The Encyclopedia of Mammals |publisher=Facts on File |year=1984 |isbn=0-87196-871-1 |editor-last=Macdonald, D. |location=New York |pages=[https://archive.org/details/encyclopediaofma00mals_0/page/200 200–203]}}</ref><ref name=":22">{{Cite book |last=Nowak |first=Ronald M. |url=http://archive.org/details/walkersmarinemam0000nowa |title=Walker's marine mammals of the world |date=2003 |publisher=Baltimore, Md. : Johns Hopkins University Press |others=Internet Archive |isbn=978-0-8018-7343-0 |pages=135–137}}</ref>

Although the narwhal and beluga are classified as separate genera, there is some evidence of [[interbreeding]] between the two. Most prominent are the remains of a whale, described by marine zoologists as unlike any known species, which were found in West Greenland around 1990. It had features midway between a narwhal and a beluga, indicating that the remains belonged to a [[Hybrid (biology)|hybrid]] between the two species (a '[[narluga]]');<ref name=":6">{{Cite journal |last1=Heide-Jørgensen |first1=Mads P. |last2=Reeves |first2=Randall R. |date=July 1993 |title=Description of an anomalous Monodontid skull from West Greenland: a possible hybrid? |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1748-7692.1993.tb00454.x |journal=Marine Mammal Science |language=en |volume=9 |issue=3 |pages=258–268 |bibcode=1993MMamS...9..258H |doi=10.1111/j.1748-7692.1993.tb00454.x |issn=0824-0469|url-access=subscription }}</ref> this was confirmed by a 2019 [[DNA analysis]].<ref>{{Cite journal |last1=Skovrind |first1=Mikkel |last2=Castruita |first2=Jose Alfredo Samaniego |last3=Haile |first3=James |last4=Treadaway |first4=Eve C. |last5=Gopalakrishnan |first5=Shyam |last6=Westbury |first6=Michael V. |last7=Heide-Jørgensen |first7=Mads Peter |last8=Szpak |first8=Paul |last9=Lorenzen |first9=Eline D. |date=20 June 2019 |title=Hybridization between two high Arctic cetaceans confirmed by genomic analysis |journal=Scientific Reports |volume=9 |issue=1 |pages=7729 |bibcode=2019NatSR...9.7729S |doi=10.1038/s41598-019-44038-0 |issn=2045-2322 |pmc=6586676 |pmid=31221994}}</ref> Whether the hybrid itself [[Hybrid (biology)#Mechanisms of reproductive isolation|could breed]] remains unknown.<ref name=":6" /><ref>{{Cite web |last=Pappas |first=Stephanie |date=20 June 2019 |title=First-ever beluga–narwhal hybrid found in the Arctic |url=https://www.livescience.com/65757-first-beluga-narwhal-hybrid.html |url-status=live |archive-url=https://web.archive.org/web/20190620233552/https://www.livescience.com/65757-first-beluga-narwhal-hybrid.html |archive-date=20 June 2019 |access-date=20 June 2019 |website=[[Live Science]]}}</ref>

=== Evolution ===

Results of a genetic study reveal that [[porpoise]]s and monodontids are closely related, forming a separate [[clade]] which diverged from other [[Delphinoidea|dolphin]]s about 11 [[million years ago]] (mya).<ref>{{Cite journal |last1=Waddell |first1=Victor G. |last2=Milinkovitch |first2=Michel C. |last3=Bérubé |first3=Martine |last4=Stanhope |first4=Michael J. |date=1 May 2000 |title=Molecular phylogenetic examination of the ''Delphinoidea'' trichotomy: congruent evidence from three nuclear loci indicates that porpoises (''Phocoenidae'') share a more recent common ancestry with white whales (''Monodontidae'') than they do with true dolphins (''Delphinidae'') |url=https://www.sciencedirect.com/science/article/pii/S1055790399907510 |journal=Molecular Phylogenetics and Evolution |volume=15 |issue=2 |pages=314–318 |bibcode=2000MolPE..15..314W |doi=10.1006/mpev.1999.0751 |issn=1055-7903 |pmid=10837160|url-access=subscription }}</ref> A 2018 molecular analysis of monodontid fossils indicates that they separated from Phocoenidae (porpoises) around 10.82 to 20.12 mya, and they are considered to be [[sister taxon|sister taxa]].<ref>{{Cite journal |last1=Racicot |first1=Rachel A. |last2=Darroch |first2=Simon A. F. |last3=Kohno |first3=Naoki |date=October 2018 |title=Neuroanatomy and inner ear labyrinths of the narwhal, ''Monodon monoceros'', and beluga, ''Delphinapterus leucas'' (Cetacea: ''Monodontidae'') |journal=Journal of Anatomy |language=en |volume=233 |issue=4 |pages=421–439 |doi=10.1111/joa.12862 |issn=0021-8782 |pmc=6131972 |pmid=30033539}}</ref> A later [[phylogenetic analysis|phylogenetic study]] conducted in 2020 suggested that the narwhal split from the beluga whale around 4.98 mya, based on data from [[mitochondrial DNA]].<ref>{{Cite journal |last1=Louis |first1=Marie |last2=Skovrind |first2=Mikkel |last3=Samaniego Castruita |first3=Jose Alfredo |last4=Garilao |first4=Cristina |last5=Kaschner |first5=Kristin |last6=Gopalakrishnan |first6=Shyam |last7=Haile |first7=James S. |last8=Lydersen |first8=Christian |last9=Kovacs |first9=Kit M. |last10=Garde |first10=Eva |last11=Heide-Jørgensen |first11=Mads Peter |last12=Postma |first12=Lianne |last13=Ferguson |first13=Steven H. |last14=Willerslev |first14=Eske |last15=Lorenzen |first15=Eline D. |date=29 April 2020 |title=Influence of past climate change on phylogeography and demographic history of narwhals (''Monodon monoceros'') |journal=Proceedings of the Royal Society B: Biological Sciences |language=en |volume=287 |issue=1925 |pages=20192964 |doi=10.1098/rspb.2019.2964 |issn=0962-8452 |pmc=7211449 |pmid=32315590}}</ref>

The fossil species ''[[Casatia thermophila]]'' of [[early Pliocene]] central [[Italy]] was described as a possible narwhal ancestor when it was discovered in 2019. ''[[Bohaskaia]]'', ''[[Denebola brachycephala|Denebola]]'' and ''[[Haborodelphis]]'' are other extinct genera known from the [[Pliocene]] of the United States.<ref name=":14" /><ref name=":2" /><ref>{{Cite journal |last1=Ichishima |first1=Hiroto |last2=Furusawa |first2=Hitoshi |last3=Tachibana |first3=Makino |last4=Kimura |first4=Masaichi |date=May 2019 |editor-last=Hautier |editor-first=Lionel |title=First monodontid cetacean (Odontoceti, Delphinoidea) from the early Pliocene of the north-western Pacific Ocean |url=https://onlinelibrary.wiley.com/doi/10.1002/spp2.1244 |journal=Papers in Palaeontology |language=en |volume=5 |issue=2 |pages=323–342 |bibcode=2019PPal....5..323I |doi=10.1002/spp2.1244 |issn=2056-2799|url-access=subscription }}</ref> Fossil evidence shows that prehistoric monodontids lived in tropical waters. They may have migrated to Arctic and subarctic waters in response to changes in the marine food chain.<ref name=":14" /><ref name=":2">{{Cite journal |last1=Vélez-Juarbe |first1=Jorge |last2=Pyenson |first2=Nicholas D. |date=1 March 2012 |title=''Bohaskaia monodontoides'', a new monodontid (Cetacea, ''Odontoceti'', ''Delphinoidea'') from the Pliocene of the western North Atlantic Ocean |url=https://www.tandfonline.com/doi/full/10.1080/02724634.2012.641705 |journal=Journal of Vertebrate Paleontology |language=en |volume=32 |issue=2 |pages=476–484 |bibcode=2012JVPal..32..476V |doi=10.1080/02724634.2012.641705 |issn=0272-4634 |s2cid=55606151|url-access=subscription }}</ref>

The following [[phylogenetic tree]] is based on a 2019 study of the family Monodontidae.<ref name=":14">{{Cite journal |last1=Bianucci |first1=Giovanni |last2=Pesci |first2=Fabio |last3=Collareta |first3=Alberto |last4=Tinelli |first4=Chiara |date=4 May 2019 |title=A new ''Monodontidae'' (Cetacea, ''Delphinoidea'') from the lower Pliocene of Italy supports a warm-water origin for narwhals and white whales |url=https://www.tandfonline.com/doi/full/10.1080/02724634.2019.1645148 |journal=Journal of Vertebrate Paleontology |language=en |volume=39 |issue=3 |pages=e1645148 |bibcode=2019JVPal..39E5148B |doi=10.1080/02724634.2019.1645148 |issn=0272-4634 |s2cid=202018525 |access-date=21 January 2024 |hdl-access=free |hdl=11568/1022436}}</ref>

{{clade
|1={{extinct}}''[[Kentriodon|Kentriodon pernix]]''
   |2={{clade
      |1={{clade
         |1=''[[Tursiops truncatus]]'' (Common bottlenose dolphin)
         |2=''[[Phocoena phocoena]]'' (Harbour porpoise)
         }}
      |label2=[[Monodontidae]]
      |2={{clade
         |1={{extinct}}''[[Haborodelphis|Haborodelphis japonicus]]''
         |2={{clade
            |1={{extinct}}''[[Denebola brachycephala]]''
            |2={{clade
               |1={{clade
                  |1={{extinct}}''[[Bohaskaia monodontoides]]''
                  |2='''''Monodon monoceros'''''
                  }}
               |2={{clade
                  |1={{clade
                     |1={{extinct}}''[[Casatia thermophila]]''
                     |2=[[Museum of Natural Sciences|IRSNB]] M 1922
                     }}
                  |2=''[[Delphinapterus leucas]]'' (Beluga whale)
                  }}
               }}
            }}
         }}
      }}
   }}