''Otodus chubutensis'', meaning "ear-shaped tooth of

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", from Ancient Greek ὠτ (ōt, meaning "ear") and ὀδούς (odoús, meaning "tooth") – thus, "ear-shaped tooth", is an extinct species of

prehistoric Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of ...

megatoothed sharks in the genus '' Otodus'', that lived during

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

, Miocene, and Pliocene epochs, approximately 28 – 5 million years ago. This shark is considered to be a close relative of the famous prehistoric megatoothed shark, '' O. megalodon''. However, as is the case with ''O. megalodon'', the classification of this species is disputed.

Taxonomy

As is the case with other known megatoothed sharks, the genus of ''O. chubutensis'' remains in dispute. The

Swiss Swiss may refer to: * the adjectival form of Switzerland * Swiss people Places * Swiss, Missouri * Swiss, North Carolina *Swiss, West Virginia * Swiss, Wisconsin Other uses *Swiss-system tournament, in various games and sports *Swiss Internation ...

naturalist

Louis Agassiz Jean Louis Rodolphe Agassiz ( ; ) FRS (For) FRSE (May 28, 1807 – December 14, 1873) was a Swiss-born American biologist and geologist who is recognized as a scholar of Earth's natural history. Spending his early life in Switzerland, he rec ...

first identified this shark as a species of '' Carcharodon'' in 1843. In 1906, Ameghino renamed this shark as ''C. chubutensis''. In 1964, shark researcher, L. S. Glikman recognized the transition of '' Otodus obliquus'' to ''C. auriculatus''. In 1987, shark researcher, H. Cappetta reorganized the ''

C. auriculatus ''Otodus auriculatus'' is an extinct species of large sharks in the genus '' Otodus'' of the family Otodontidae, closely related to the sharks of the genus '' Otodus'', and also closely related to the later species megalodon. Its teeth were larg ...

'' - ''O. megalodon'' lineage and placed all related megatoothed sharks along with this species in the genus ''

Carcharocles ''Otodus'' is an extinct genus of mackerel shark which lived from the Paleocene to the Pliocene epoch. The name ''Otodus'' comes from Ancient Greek (, meaning "ear") and (, meaning "tooth") – thus, "ear-shaped tooth". Anatomy This shark is k ...

''. Finally, the complete ''Otodus obliquus'' to ''O. megalodon'' progression became clear and has since gained the acceptance of many shark researchers. Within the ''Otodus'' lineage; ''O. chubutensis'' is the succeeding species of '' O. angustidens'' and is followed by ''O. megalodon''. In short, ''O. chubutensis'' is considered a possible ancestor of ''O. megalodon''. However, due to its co-existence with ''O. megalodon'' during the Miocene and Pliocene epochs, it is regarded as a morpho-species.

Size

''Otodus chubutensis'' was larger than '' O. angustidens''. Teeth of ''C. chubutensis'' can approach in slant height (diagonal length), which according to a size estimation method proposed by Gottfried ''et al.'', in 1996, indicate a long specimen.

Paleoecology

Paleontological research suggests that this species may have changed habitat preferences through time, or it may have had enough behavioral flexibility to occupy different environments at different times.

Diet

''Otodus chubutensis'' was likely an apex predator and commonly preyed upon fish,

sea turtles Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerhead, ...

cetaceans Cetacea (; , ) is an infraorder of aquatic mammals that includes whales, dolphins, and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively carnivorous diet. They propel them ...

(e.g. whales), and

sirenids Sirenidae, the sirens, are a family of neotenic aquatic salamanders. Family members have very small fore limbs and lack hind limbs altogether. In one species, the skeleton in their fore limbs is made of only cartilage. In contrast to most other ...

Fossil record

This species is also known from fossil teeth and some fossilized

vertebral centra The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...

. Shark

skeleton A skeleton is the structural frame that supports the body of an animal. There are several types of skeletons, including the exoskeleton, which is the stable outer shell of an organism, the endoskeleton, which forms the support structure inside ...

s are composed of

cartilage Cartilage is a resilient and smooth type of connective tissue. In tetrapods, it covers and protects the ends of long bones at the joints as articular cartilage, and is a structural component of many body parts including the rib cage, the neck an ...

and not bone, and cartilage rarely gets fossilized. Hence, fossils of ''O. chubutensis'' are generally poorly preserved. Although the teeth of ''O. chubutensis'' are morphologically similar to teeth of ''O. megalodon'', they are comparatively slender with curved crown, and with presence of lateral heels feebly serrated. Fossils of this species have been found in

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

, South America, Africa, and Europe.

Locations

;South America''Otodus chubutensis''
at

Fossilworks Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...

.org * Chilcatay Formation, Peru * Pirabas Formation, Brazil *

Jimol Formation The Jimol Formation ( es, Formación Jimol, N1j) is a fossiliferous geological formation of the Cocinetas Basin in the northernmost department of La Guajira. The formation consists of calcareous lithic and fossiliferous sandstones, siltstones an ...

, Colombia * Cantaure Formation, Venezuela ;North America *

Culebra Formation The Culebra Formation (Tcb)Geologic Map, 1980 is a geologic formation in Panama. It preserves fossils dating back to the Miocene period; Early Miocene epoch, Aquitanian to Burdigalian stages ( Late Arikareean to Hemingfordian in the NALMA classif ...

, Panama * Arcadia Formation, Florida *

Pungo River Formation The Pungo River Formation is a geologic formation in North Carolina. It preserves fossils dating back to the Middle Miocene. Economic significance The Pungo River Formation is mined extensively for its phosphorite deposits. See also * List ...

, North Carolina * Calvert Formation, Delaware ;Europe *

Bolognano Formation Bolognano is a ''comune'' (municipality) and town in the province of Pescara in the Abruzzo region of Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located ...

, Italy

References

External links

Carcharocles: Extinct Megatoothed shark
from ELASMO

from Fossilguy.com {{Taxonbar, from=Q5038155 chubutensis Oligocene sharks Miocene sharks Pliocene sharks Prehistoric fish of Africa Fossils of Egypt Prehistoric fish of Europe Fossils of Italy Paleogene fish of North America Neogene fish of North America Prehistoric fish of South America Paleogene animals of South America Neogene animals of South America Paleogene Argentina Neogene Argentina Fossils of Argentina Fossil taxa described in 1843 Taxa named by Louis Agassiz