Squalicorax

{{Short description|Extinct genus of sharks}} {{Automatic taxobox | fossil_range = Albian-Maastrichtian, {{Fossil range|109.56|66.0|ref=<ref name=GeologicTime>{{cite book|author1= Ogg, J.G.|author2=Hinnov, L.A.|chapter=Cretaceous|year=2012|pages=793–853 |title=The Geologic Time Scale|doi=10.1016/B978-0-444-59425-9.00027-5|isbn=9780444594259}}</ref><ref name=Smart2007>{{cite journal|author=Smart, P.J.|year=2007|title=Anacoracid shark teeth (Chondrichthyes, Vertebrata) from the early Cretaceous Albian sediments of Leighton Buzzard, south-central England|journal=Proceedings of the Geologists' Association|volume=118|issue=4|pages=375–380|doi=10.1016/s0016-7878(07)80005-8}}</ref>}} | image = Squalicorax pristodontus Agassiz, 1843 1.jpg | image_caption = ''Squalicorax pristodontus'' tooth from the late Maastrichtian of Khouribga, Morocco | taxon = Squalicorax | authority = Whitley, 1939 | type_species = {{extinct}}'''''Squalicorax pristodontus''''' | type_species_authority = Agassiz, 1835 | subdivision_ranks = Species | subdivision = {{collapsible list|title=List of species| * {{extinct}}'''''S. pristodontus''''' Agassiz, 1835 (type) * {{extinct}}'''''S. appendiculatus''''' Agassiz, 1839 * {{extinct}}'''''S. falcatus''''' Agassiz, 1843 ** {{extinct}}'''''S. falcatus praecursor''''' Sokolov, 1978 * {{extinct}}'''''S. kaupi''''' Agassiz, 1843 * {{extinct}}'''''S. heterodon''''' Reuss, 1845 * {{extinct}}'''''S. obliquus''''' Reuss, 1845 ** {{extinct}}'''''S. obliquus subserratus''''' Glückman, 1980 * {{extinct}}'''''S. lindstromi''''' Davis, 1890 * {{extinct}}'''''S. curvatus''''' Williston, 1900 * {{extinct}}'''''S. bassanii''''' Gemmellaro, 1920 * {{extinct}}'''''S. baharijensis''''' Stromer, 1927 * {{extinct}}'''''S. primaevus''''' Dalinkevicius, 1935 * {{extinct}}'''''S. kugleri''''' Leriche, 1938 * {{extinct}}'''''S. yangaensis''''' Carteville & Casier, 1943 * {{extinct}}'''''S. dalinkevichiusi''''' Glückman & Shvazhaite, 1971 * {{extinct}}'''''S. mississippiensis''''' Glückman, 1971 * {{extinct}}'''''S. volgensis''''' Glückman, 1971 * {{extinct}}'''''S. obruchevi''''' Glückman, 1980 * {{extinct}}'''''S. sagisicus''''' Glückman, 1980 * {{extinct}}'''''S. santonicus''''' Glückman & Zhelezko, 1980 * {{extinct}}'''''S. papulovi''''' Zhelezko, 1980 * {{extinct}}'''''S. africanus''''' Cappetta, 1991 * {{extinct}}'''''S. primigenius''''' Landemaine, 1991 * {{extinct}}'''''S. coquandi''''' Vullo ''et al.'', 2007 * {{extinct}}'''''S. priscoserratus''''' Siversson ''et al.'', 2007 * {{extinct}}'''''S. bernardezi''''' Guinot ''et al.'', 2013 * {{extinct}}'''''S. benguerirensis''''' Cappetta ''et al.'', 2014 * {{extinct}}'''''S. microserratus''''' Cappetta ''et al.'', 2014 * {{extinct}}'''''S. deckeri''''' Bice & Shimada, 2016 * {{extinct}}'''''S. lalunaensis''''' Guinot & Carrillo-Briceño, 2018 * {{extinct}}'''''S. moodyi''''' Guinot & Carrillo-Briceño, 2018 * {{extinct}}'''''S. acutus''''' Siversson ''et al.'', 2019 * {{extinct}}'''''S. bazzii''''' Siversson ''et al.'', 2019 * {{extinct}}'''''S. mutabilis''''' Siversson ''et al.'', 2019 }} }}

'''''Squalicorax''''', commonly known as the '''crow shark''', is a genus of extinct lamniform shark known to have lived during the Cretaceous period. The genus had a global distribution in the Late Cretaceous epoch. Multiple species within this genus are considered to be wastebasket taxa due to morphological similarities in the teeth.

==Etymology== The name ''Squalicorax'' is derived from the Latin ''squalus'' for shark and the Greek κόραξ, "''korax''" for raven.{{Why|date=November 2025|reason=Why were they named this?}}

==Description== [[File:Squalicorax NMNH.jpg|left|thumb|502x502px| Near-complete skeleton of ''Squalicorax falcatus'' (USNM 425665)]] ''Squalicorax'' was a medium-sized shark, typically measuring about {{convert|1.8|-|3|m|ft}} long. The largest specimen of ''S. pristodontus'', SDSM 47683, was significantly larger, measuring up to {{convert|4.8|m|ft}} long.<ref name=SC05>{{cite journal|author1=Shimada, K.|author2=Cicimurri, D.J.|year=2005|title=Skeletal anatomy of the Late Cretaceous shark, ''Squalicorax'' (Neoselachii, Anacoracidae)|journal=Paläontologische Zeitschrift|volume=79|issue=2 |pages=241–261|doi=10.1007/BF02990187}}</ref>

Their bodies were similar to the modern gray reef sharks, but the shape of the teeth is strikingly similar to that of a tiger shark.{{Citation needed|date=November 2025}} The teeth are numerous, relatively small, with a curved crown and serrated, up to {{convert|2.5|–|3|cm|abbr=on}} in height. Large numbers of fossil teeth have been found in Europe, North Africa, and North America.<ref name=":0">{{Cite book |first=Henri |last=Cappetta |title=Handbook of paleoichthyology |date=2012 |publisher=Friedrich Pfeil |isbn=978-3-89937-148-2 |oclc=808490829}}</ref> Squalicorax is one of three Cretaceous lamniformes to garner serrations along with ''Pseudocorax'' and ''Galeocorax''.<ref name=":0" /> The world's largest and most complete semi-articulated fossil of ''Squalicorax'' was found in 2014 in stores of the Canadian Fossil Discovery Centre in Morden, Manitoba, in Canada, where it is now displayed. It measures more than 3 m in length.<ref>{{Cite news|url=http://www.cbc.ca/news/canada/manitoba/crow-shark-fossil-believed-to-be-world-s-largest-found-in-manitoba-1.2725575|title=World's largest crow shark fossil surfaces in Manitoba|work=CBC News|access-date=2017-08-01|language=en}}</ref>

''Squalicorax'' was a coastal predator and scavenger, as evidenced by a ''Squalicorax'' tooth found embedded in the metatarsal (foot) bone of a terrestrial hadrosaurid dinosaur that most likely died on land and ended up in the water.<ref>{{cite journal|doi=10.2307/3515295|jstor=3515295|title=Scavenging by Sharks of the Genus Squalicorax in the Late Cretaceous of North America|journal=PALAIOS|volume=12|issue=1|pages=71–83|year=1997|last1=Schwimmer|first1=David R.|last2=Stewart|first2=J. D.|last3=Williams|first3=G. Dent|bibcode=1997Palai..12...71S}}</ref> Other food sources included sea turtles, mosasaurs, ichthyodectid fish, and other marine life. Tooth marks from this shark have also been found on the bones of ''Pteranodon'', but whether the shark actively snatched such large pterosaurs out of the air, attacked them as they dove after prey, or were simply scavenging is not known.<ref>{{Cite web|url=https://www.nationalgeographic.com/science/2018/10/news-sharks-eating-pterosaurs-fossils-cretaceous-paleontology/|archive-url=https://web.archive.org/web/20181003163916/https://www.nationalgeographic.com/science/2018/10/news-sharks-eating-pterosaurs-fossils-cretaceous-paleontology/|url-status=dead|archive-date=October 3, 2018|title=Prehistoric sharks feasted on flying reptiles, fossil reveals|date=October 3, 2018|website=Science & Innovation}}</ref>

===Description of selected species=== thumb|Fossil teeth of ''S. falcatus'' from Kansas

The following are the best studied species for which relatively complete skeletons are described: thumb|253px|right|''Squalicorax falcatus'' * ''Squalicorax falcatus'' (Agassiz, 1843) – is a medium-sized shark with a broad snout and relatively small teeth. Its length reached almost {{convert|3|m|abbr=on}}. It lived during the Cenomanian to early Santonian (Campanian). Complete skeletons are known from sediments of the Western Inland Sea of the Cretaceous in Kansas, South Dakota, and Wyoming, all in the USA. The teeth are also found in France, the Czech Republic, Canada, and Morocco. Given the small teeth, this species is considered a hunter of small prey. However, teeth marks on the bones of marine reptiles are evidence that these shark also fed on carrion. The body shape and structure of the trunk's placoid scales indicate the ability to swim quickly. A fully articulated {{convert|1.9|m|abbr=on}} long fossil skeleton of ''Squalicorax falcatus'' has been found in Kansas, evidence of its presence in the Western Interior Seaway.<ref name="SC05" /> [[File:Kansas sea2DB.jpg|thumb|right|Two ''Squalicorax'' and a ''Cretoxyrhina'' circling around a dead ''Claosaurus'']] * ''Squalicorax kaupi'' (Agassiz, 1843) is from the late Santonian to the late Maastrichtian of North America, New Zealand, Japan, Africa, Europe, Kazakhstan, Jordan. and other places. It was slightly larger than the preceding species, of which it was probably an ancestor. * ''Squalicorax pristodontus'' (Agassiz, 1843) is the largest species, exceeding {{convert|3|m|ft}} in length. From the size of its largest known teeth, it can be estimated that ''S. pristodontus'' grew to {{convert|4.8|m|ft}} in length.<ref name=SC05/> It lived during the late Campanian to early Maastrichtian of North America, France, the Netherlands, Egypt, Morocco, and Madagascar. The relatively complete remains (vertebrae and fragments of jaws) have been found in marine sediments in North America. It is the species with the largest teeth, these teeth being loosely spaced and relatively very large in comparison with other species. In this genus of sharks, studies have shown no precise correlation between the size of the teeth and the length of the body. They could eat relatively large prey and carrion.<ref name=":1">{{Cite book |last1=Lucas |first1=Spencer G. |url=https://books.google.com/books?id=rCDYCQAAQBAJ&dq=squalicorax+&pg=PA177 |title=Late Cretaceous Vertebrates from the Western Interior: Bulletin 35 |last2=Sullivan |first2=Robert M. |date=2006-01-01 |publisher=New Mexico Museum of Natural History and Science |language=en}}</ref> * ''Squalicorax volgensis'' - the oldest species of the genus, from the Early Cretaceous of the Volga – was described by L. Glickman ''et al.'' in 1971. The teeth of this species had virtually no serration. They are known from the Albian to the Turonian Age in Eastern and Western Europe, as well as Texas.<ref name=":1" />

==References== {{Reflist}}

==Sources== * H. Cappetta, ''Handbook of Paleoichthyology'' (Gustav Fischer, 1987)

==External links== {{Commons category|Squalicorax}} * [http://www.elasmo.com/frameMe.html?file=genera/cretaceous/squalicorax.html&menu=bin/menu_genera-alt.html Elasmo.com page on Squalicorax] * [http://www.oceansofkansas.com/sharks.html ''Cretoxyrhina mantelli'' - The Ginsu Shark and ''Squalicorax falcatus'' - The Crow Shark] * [http://www.elasmo-research.org/education/evolution/squalicorax.htm Squalicorax beim ReefQuest Centre for Shark Research]

Category:Anacoracidae Category:Cretaceous sharks Category:Late Cretaceous fish of North America Category:Cretaceous fish of Europe Category:Fossil taxa described in 1939 Category:Demopolis Chalk Category:Mooreville Chalk Category:Prehistoric shark genera