Otodus obliquus
Extinct species of shark
From Wikipedia, the free encyclopedia
Otodus obliquus is an extinct species of large mackerel shark that lived in Early Paleocene to Early Eocene, between 65 to 54 milion years ago. It is considered one of first members of Otodus sharks and the type species of genus. It's considered as the ancestor of the famous giant mackerel shark, Megalodon. The largest individuals would have measured 8–9 metres (26–30 ft) long.
| Otodus obliquus | |
|---|---|
| |
| Jaws of O. obliquus | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Chondrichthyes |
| Subclass: | Elasmobranchii |
| Division: | Selachii |
| Order: | Lamniformes |
| Family: | †Otodontidae |
| Genus: | †Otodus |
| Species: | †O. obliquus |
| Binomial name | |
| †Otodus obliquus Agassiz, 1843 | |
| Synonyms | |
Taxonomy
History
As is the case with most sharks of the genus Otodus, their classification is still a subject of debate. In 1838, the naturalist Louis Agassiz named O. obliquus as a species of the genus Lamna, naming it L. obliqua.[1] However, about 5 years after its naming, Louis Agassiz reclassified the same shark into a new genus, Otodus, but still within the same family, Lamnidae.[2] In the same year, he renamed several other species of sharks previously classified in the genus Lamna and Carcharodon, such as O. lanceolatus and O. giganteus. However, in 1942, Maurice Leriche reclassified O. giganteus as a junior synonym of O. obliquus.[citation needed] In 1923 it was suggested that Megalodon and many of its relatives be moved to the genus Carcharocles, with its family still uncertain. In 1964, the paleontologist Glickman grouped Otodus obliquus, Carcharocles megalodon, C. subauriculatus and C. chubutensis in the now extinct family Otodontidae, moving C. megalodon, C. subauriculatus and C. chubutensis to a new genus, Megaselachus.
Current classification
In most recent articles, O. obliquus is grouped in the family Otodontidae, along with its closest relatives, such as O. megalodon and O. auriculatus for example, with the most currently accepted classification placing them in the genus Otodus or some in the genus Carcharocles. The reason why O. obliquus and O. megalodon are similar to the Salmon shark (Lamna ditropis) and the modern Great white shark (Carcharodon carcharias) according to current research is due to evolutionary convergence, which is when two unrelated groups or species develop similar appearance and anatomy due to similar evolutionary pressures.[3][4]
Although many are similar, the ones considered ancestors of the modern Great white shark (Carcharodon carcharias) are Carcharodon hastalis, Carcharodon plicatilis, and C. hubbelli, not O. megalodon.[5]
Description
Paleoecology
Diet
Otodus obliquus was a top predator, hunting large fish, turtles, other sharks, and small species of early cetaceans. [citation needed]
Distribution
Like all sharks, the body of O. obliquus was made of cartilage, not bones, therefore, most of the fossils of O. obliquus are known only by teeth and some vertebrae. Fossils of O. obliquus have been found almost all over the world, having a cosmopolitan distribution, from the Americas to Asia.[citation needed]