Carcharodon

The fossil ancestry of Carcharodon is an active area of research and debate, given the dearth of the fossil record and the incompleteness of found specimens. Most Carcharodon fossil remains of are in the form of teeth, along with some vertebral centra. This is the norm for fossilized Chondrichthyans, since a shark's skeleton is made of cartilage and soft tissues don't preserve well. Thus, assessing relationships between fossil species relies largely on the form of their teeth. This difficulty is compounded by the incomplete fossil record of Lamnids. However, some researchers have proffered Macrorhizodus, Isurolamna, and Cretalamna as candidates for genera ancestral to Carcharodon, taxa ranging from the Eocene to the Cretaceous.Martin, A. P. (1996). "Systematics of the Lamnidae and the Origination Time of Carcharodon carcharias Inferred from the Comparative Analysis of Mitochondrial DNA Sequences". In Klimley, A. P.; Ainley, D. G. (eds.). Great White Sharks: The Biology of Carcharodon carcharias. Academic Press. pp. 49–53. {{doi|10.1016/B978-0-12-415031-7.X5000-9}}{{cite book | editor-last=Klimley | editor-first=A. Peter | editor-last2=Ainley | editor-first2=David G. | title=Great white sharks : the biology of Carcharodon carcharias | publisher=Academic Press | publication-place=San Diego | date=1996 | isbn=978-0-08-053260-8 | oclc=392312939 | doi=10.1016/b978-0-12-415031-7.x5000-9 | last1 = Applegate | first1 = Shelton P. | last2 = Espinosa-Arrubarrena | first2 = Luis | chapter = The Fossil History of Carcharodon and Its Possible Ancestor, Cretolamna: A Study in Tooth Identification | pages = 19–36}}

Carcharodon is well-represented in the fossil record by the Middle Miocene. The first widespread, cosmopolitan species being C. hastalis, with fossils recovered from North America, South America, Europe, Australia, and Asia.{{Cite web |date=2017-03-30 |title=Carcharodon hastalis |url=https://www.floridamuseum.ufl.edu/florida-vertebrate-fossils/species/carcharodon-hastalis/ |access-date=2023-01-04 |website=Florida Museum |language=en-US}} The modern great white shark has been posited to have evolved from C. hastalis through a transitional species, C. hubbelli.

File:Carcharodon hastalis tooth.jpg

Study of white shark taxonomy is complicated by nomenclature and repeated taxonomic reassignments of various species. C. hastalis, C. subserratus, and C. planus traditionally were placed in Isurus, given their superficial similarity to the teeth of mako sharks, leading many modern shark tooth collectors to still refer to these extinct species as "makos." They were later reassigned to a new genus, Cosmopolitodus,Glikman , L. S. (1964). "Sharks of the Paleogene their stratigraphic significance." Nakua Press, Moscow, 229 pp. [Russian] a genus maintained as valid in some current literature, and considered a junior synonym of Carcharodon in others.Yun, C. (2021). "A tooth of the extinct lamnid shark, Cosmopolitodus planus comb. nov. (Chondrichthyes, Elasmobranchii) from the Miocene of Pohang City, South Korea" (PDF). Acta Palaeontologica Romaniae. 18 (1): 9–16. {{doi|10.35463/j.apr.2022.01.02}} S2CID 242113412. C. hastalis has also been described as two morphotypes, "broad-form" and "narrow-form," which some authors have split into two species, C. plicatilis (xiphodon) and C. hastalis, respectively.Whitenack, L. B. and Gottfried, M. D. (2010). "A morphometric approach for addressing tooth-based species delimitation in fossil Mako sharks, Isurus (Elasmobranchii, Lamniformes)." Journal of Vertebrate Paleontology, 30, 17–25.Cione A. L., Cabrera D. A., et al (2012). "Oldest record of the Great White Shark (Lamnidae, Carcharodon; Miocene) in the Southern Atlantic", Geobios 45, 167-172 {{doi|10.1016/j.geobios.2011.06.002}} C. subserratus, historically known as C. escheri under the genus Carcharomodus,Kriwet, J., Mewis, H., and Hampe, O. 2015. A partial skeleton of a new lamniform mackerel shark from the Miocene of Europe. Acta Palaeontologica Polonica 60 (4): 857–875. has recently been reclassified back in to the genus Carcharodon as C. subserratus.Godfrey, Stephen J., ed. (2018-09-25). "The Geology and Vertebrate Paleontology of Calvert Cliffs, Maryland, USA". Smithsonian Contributions to Paleobiology (100): 2–274. {{doi|10.5479/si.1943-6688.100}} ISSN 1943-6688.

The fossil "mega-toothed" sharks like megalodon have also traditionally been placed in Carcharodon, but most current literature refutes this position, placing mega-toothed sharks in a separate family, Otodontidae, and genus, Otodus (Carcharocles).Kent, B. W. (2018). "The Cartilaginous Fishes (Chimaeras, Sharks, and Rays) of Calvert Cliffs, Maryland, USA". In Godfrey, S. J. (ed.). The Geology and Vertebrate Paleontology of Calvert Cliffs, Maryland. Smithsonian Contributions to Paleobiology. The Smithsonian Institution. pp. 45–157. {{doi|10.5479/si.1943-6688.100}} ISSN 1943-6688. S2CID 134274604. Carcharodon caifassii is the other species in genus Carcharodon. It is a debated species, and is considered dubious. It lived in the Miocene and Pliocene period and was a possible ancestor of the great white shark (Carcharodon carcharias).{{cite web |last1=Lawley |first1=Lawley |title=Carcharodon caifassi |website=Mindat.org |publisher=1876 }}{{cite web |last1=Hay., 1902 |first1=Hay., 1902 |title=Carcharodon |website=Mindat.org |publisher=1902 }}

• Carcharodon carcharias (Linnaeus, 1758) (the great white shark)
• †Carcharodon carcharias-f (Lawley, 1876)
• †Carcharodon hubbelli (Ehret et al., 2012) (Hubbell's white shark)
• †Carcharodon hastalis? (Agassiz, 1843)Agassiz, L. J. R. 1833–1844. Recherches sur les poisons fossiles. Text (5 vols; I., xlix + 188 pp., II xii + 310 + 366 pp., III viii+390pp., IV xvi+296pp., V xii+122+160pp.) and Atlas. Imprimerie de Petitpierre, Neuchâtel.
• †Carcharodon planus? (Agassiz, 1856)Agassiz, L., 1856. Notice on the fossil fishes found in California by W.P. Blake. American Journal of Science and Arts, Series 2, 21: 272–275.
• †Carcharodon subserratus (escheri)? (Agassiz, 1843)
• †Carcharodon plicatilis (xiphodon)? (Agassiz, 1843)
• †Carcharodon caifassii (Lawley, 1876){{cite web |last1=Lawley |first1=Lawley |url=https://shark-references.com/species/view/Carcharodon-caifassii |title=Carcharodon caifassii |website=Shark-References |publisher=1876 }}

{{Reflist}}

{{Lamniformes}}

{{Taxonbar|from=Q2938003}}

{{Authority control}}

Category:Taxa named by Andrew Smith (zoologist)

Category:Shark genera

Category:Fish genera with one living species