Otodus angustidens[1] is a species of prehistoric megatoothed sharks in the genus Otodus, which lived during the Oligocene and Miocene epochs about 33 to 22 million years ago.[2] The largest individuals were about 11–12 metres (36–39 ft) long. This shark is related to another extinct megatoothed shark,the famous Otodus megalodon.[2]
| Otodus angustidens | |
|---|---|
| |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Chondrichthyes |
| Subclass: | Elasmobranchii |
| Subdivision: | Selachimorpha |
| Order: | Lamniformes |
| Family: | †Otodontidae |
| Genus: | †Otodus |
| Species: | †O. angustidens
|
| Binomial name | |
| †Otodus angustidens Agassiz, 1843
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| Synonyms | |
|
Carcharocles angustidens
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Taxonomy edit
The Swiss naturalist Louis Agassiz, first identified this shark as a species of genus Carcharodon in 1835.
In 1964, shark expert, L. S. Glikman recognized the transition of Otodus obliquus to C. auriculatus and moved C. angustidens to genus Otodus. (See "external links" below)
However, in 1987, shark expert H. Cappetta recognized the C. auriculatus - C. megalodon lineage and placed all related megatooth sharks along with this species in the genus Carcharocles. The complete Otodus obliquus to C. megalodon transition then became clear and has since gained the acceptance of many other experts with the passage of time. Within the Carcharocles lineage, C. angustidens is the species succeeding C. sokolovi and is followed by C. chubutensis.[2]
In 2001, a discovery of the best preserved Carcharocles angustidens specimen to date by two scientists, Michael D. Gottfried and Ewan Fordyce, has been presented by the team as evidence for close morphological ties with the extant great white shark, and the team argued that Carcharocles angustidens, along with all other related megatooth sharks, including Carcharocles megalodon, should be assigned to Carcharodon as was done before by Louis Agassiz.,[3] although this is not internationally accepted by the scientific community.
Size estimation edit
Like other known megatooth sharks, the fossils of O. angustidens indicate that it was considerably larger than the extant great white shark, with the largest individuals possibly measuring up to 11–12 metres (36–39 ft) long.[4][5] A well preserved specimen from New Zealand is estimated at 9.3 m (31 ft) in length.[3] This specimen had teeth measuring up to 9.87 cm (3.89 in) in diagonal length, and vertebral centra around 1.10 cm (0.43 in) in diameter.[3] Smaller individuals were about 6–6.6 metres (20–22 ft) long, still larger than the extant great white shark.[6][3]
Dentition edit
The dental formula for O. angustidens is 2.1.5.43.0.6.3
Diet edit
O. angustidens was an apex predator and likely preyed upon penguins, fish, dolphins, and baleen whales.
Fossil record edit
As is the case with most extinct sharks, this species is also known from fossil teeth and some fossilized vertebral centra. Shark skeletons are composed of cartilage and not bone, and cartilage rarely gets fossilized. Hence, fossils of O. angustidens are generally poorly preserved. To date, the best preserved specimen of this species have been excavated from New Zealand, which comprises 165 associated teeth and about 35 associated vertebral centra.[3] This specimen is around 26 million years old. O. angustidens teeth are noted for their triangular crowns and small side cusps that are fully serrated. The serrations are very sharp and very well pronounced. O. angustidens was a widely distributed species with fossils found in:[7] A fossil bed in South Carolina suggests that O. angustidens utilized the area as a birthing ground and nursery for their pups, as 89% of the teeth found in the area belonged to juveniles, 3% belonged to infants, and 8% belonged to adults.[8]
- North America
- Yazoo Formation, Alabama
- Jewett Sand Formation, California
- Clinchfield Formation, Georgia
- Calvert Formation, Maryland
- Jackson Group, Mississippi
- Kirkwood Formation, New Jersey
- Castle Hayne Formation, North Carolina
- Hawthorne Formation, South Carolina[9]
- Chandler Bridge Formation, South Carolina[10]
- Europe
- Asia
- Oceania
- Africa[3]
- South America[3]
See also edit
References edit
- ^ Shimada, K.; Chandler, R. E.; Lam, O. L. T.; Tanaka, T.; Ward, D. J. (2016). "A new elusive otodontid shark (Lamniformes: Otodontidae) from the lower Miocene, and comments on the taxonomy of otodontid genera, including the 'megatoothed' clade". Historical Biology. 29 (5): 1–11. doi:10.1080/08912963.2016.1236795. S2CID 89080495.
- ^ a b c Renz, Mark (2002). Megalodon: Hunting the Hunter. PaleoPress. pp. 26–30. ISBN 0-9719477-0-8.
- ^ a b c d e f g Gottfried M.D., Fordyce R.E (2001). "An associated specimen of Carcharodon angustidens (Chondrichthyes, Lamnidae) from the Late Oligocene of New Zealand, with comments on Carcharodon interrelationships". Journal of Vertebrate Paleontology. 21 (4): 730–739. doi:10.1671/0272-4634(2001)021[0730:AASOCA]2.0.CO;2. S2CID 86092645.
- ^ Kast, Emma R.; Griffiths, Michael L.; Kim, Sora. L.; Rao, Zixuan C.; Shimada, Kensu; Becker, Martin A.; Maisch, Harry M.; Eagle, Robert A.; Clarke, Chelesia A.; Neumann, Allison N.; Karnes, Molly E.; Lüdecke, Tina; Leichliter, Jennifer N.; Martínez-García, Alfredo; Akhtar, Alliya A.; Wang, Xingchen T.; Haug, Gerald H.; Sigman, Daniel M. (22 June 2022). "Cenozoic megatooth sharks occupied extremely high trophic positions". Science Advances. 8 (25): eabl6529. Bibcode:2022SciA....8L6529K. doi:10.1126/sciadv.abl6529. PMC 9217088. PMID 35731884.
- ^ Miller, Addison E.; Gibson, Matthew L.; Boessenecker, Robert W. (2021). "A megatoothed shark (Carcharocles angustidens) nursery in the Oligocene Charleston Embayment, South Carolina, USA". Palaeontologia Electronica. 24 (2). a19. doi:10.26879/1148.
- ^ Trif, N.; Ciobanu, R.; Vlad, C.A. (2016). "The first record of the giant shark Otodus megalodon (Agassiz, 1835) from Romania". Brukenthal. Acta Musei. 11 (3): 507–526.
- ^ Carcharocles angustidens at Fossilworks.org
- ^ "24 million-year-old nursery for baby megasharks discovered in South Carolina". Live Science. 19 October 2020.
- ^ "C. angustidens fossils from Black River Fossils". Archived from the original on 2016-06-24. Retrieved 2010-06-02.
- ^ Miller, A. E.; Gibson, M. L.; Boessenecker, R. W. (2021). "A megatoothed shark (Carcharocles angustidens) nursery in the Oligocene Charleston Embayment, South Carolina, USA". Palaeontologia Electronica. 24 (2): Article number 24.2.a19. doi:10.26879/1148.
Further reading edit
- Glikman, L.S., 1980. Evolution of Cretaceous and Caenozoic Lamnoid Sharks:3-247, pls.1-33. Moscow.
- Jordan, D.S. & Hannibal, H., 1923. Fossil Sharks and Rays of the Pacific Slope of North America. Bulletin of the Southern California Academy of Sciences, 22:27-63, plates 1–9.