Otodus

All species are known from their fossilized teeth, and four of them (O. obliquus, O. auriculatus, O. angustidens and O. megalodon) are also known from their fossilized vertebral centra. Like other elasmobranchs, the skeletons of Otodus spp. were composed of cartilage, resulting in relatively few preserved skeletal structures appearing within the fossil record. The teeth of this shark are large with triangular crown, smooth cutting edges, and visible cusps on the roots. (tongue-side) view of O. obliquus teeth from the Eocene near Khouribga, Morocco Size estimation The fossils of Otodus sharks indicate that they were very large macro-predatory sharks. The largest known teeth of O. obliquus measure about in height. The vertebral centrum of this species are over 12.7 cm (5 inch) wide. Other species were much larger, with O. auriculatus, O. angustidens and O. chubutensis being estimated to have reached maximum body lengths of , and , respectively. Studies have estimating the maximum body length of O. megalodon have varied, stating measurements ranging from approximately to 24.3 m (80ft) . Growth and reproduction Comparative studies of the centrum radii and growth rings on the vertebrae of O. obliquus and the extant great white shark through X-rays have concluded that the sizes of the vertebrae at birth are similar, meaning that the offspring of both species would have the same size (between in length); they also revealed that they grew at the same rate until reaching 10 years of age, during which O. obliquus would have become sexually mature and attained a growth rate faster than that of the extant great white shark. A sexually mature individual of O. obliquus would have measured about long. Like the extant great white shark, it is likely that males could have reached sexual maturity earlier than females. O. angustidens also had a faster growth rate than the extant great white shark, while O. auriculatus and the extant great white shark had a similar growth rate. O. megalodon had a much faster growth rate (nearly two times that of the extant great white), but likely had an extremely delayed sexual maturity based on the result of the study that the slowing or cessation of somatic growth in megalodon occurred around 25 years of age. Like contemporaneous sharks, at least two species of Otodus (O. angustidens and O. megalodon) made use of nursery areas to birth their young in, specifically warm-water coastal environments with large amounts of food and protection from predators. A possible nursery area of O. obliquus has been discovered in the Ganntour basin, Morocco. ==Distribution==

Otodus had a worldwide distribution, as fossils have been excavated from Africa, Asia, Europe, North America, South America, Caribbean and Australia. ==Diet==

Otodus was likely the apex predator of its time and commonly preyed upon fish, sea turtles, cetaceans (e.g. whales), and sirenids. There is also potential evidence that Otodus hunted raptorial sperm whales; a tooth belonging to an undetermined long physeteroid closely resembling those of Acrophyseter discovered in the Nutrien Aurora Phosphate Mine in North Carolina suggests that a megalodon or O. chubutensis may have aimed for the head of the sperm whale in order to inflict a fatal bite, the resulting attack leaving distinctive bite marks on the tooth. While scavenging behavior cannot be ruled out as a possibility, the placement of the bite marks is more consistent with predatory attacks than feeding by scavenging, as the jaw is not a particularly nutritious area for a shark to feed or focus on. The fact that the bite marks were found on the tooth's roots further suggest that the shark broke the whale's jaw during the bite, suggesting the bite was extremely powerful. The fossil is also the first known instance of an antagonistic interaction between a sperm whale and an otodontid shark recorded in the fossil record. Schwenk et al. (2026) compared zinc enrichment of the enameloid of Otodus obliquus and O. megalodon, finding evidence of higher concentrations of zinc in regions of teeth of O. megalodon which were affected by high stress during feeding and finding evidence of less pronounced spatial variation of zinc in O. obliquus, and interpret this finding as suggestive of a shift from a fish-based diet to a more marine mammal-based diet during the evolutionary history of otodontid sharks. ==Evolution==

It is widely believed that the genus originates from a lineage of sharks belonging to the genus Cretalamna, due to strong similarities in tooth morphology. Scientists determined that Otodus evolved into the genus Carcharocles, given substantial fossil evidence in the form of transitional teeth. == Undescribed species ==

Otodus includes species that have not yet been formally described. Otodus debrayi Otodus debrayi is a species known to have lived from the Early Eocene to Middle Eocene epoch. This species has been found in Africa, North America, Central Asia, and Europe, dating from 47.8 to 38 million years ago. Otodus poseidoni Otodus poseidoni is a controversial species that was described in 1999, measuring aproximately 12 meters. Its teeth measure up to in length. Some scientists consider these possible species to be a variation of Otodus sokolovi, Otodus aksuaticus or Otodus auriculatus, but this is not confirmed. Otodus minor It was descrebried by Giebel as a Carcharodon species, now replaced in Otodus genus, considered a possible synonym of O. obliquus. It includes a other variation, named as O. minor var. turkmenicus or simple, O. m. turkmenicus. Fossils of O. minor was found in Kazakhstan, considered one of the first species of the genus. Otodus naidini It is a rare species, known from only teeth of Kazakhstan, some paleontologist suggest that O. naidini is a junior synonym of O. obliquus or O. limhamnensis. "Carcharocles casieri" It's a undescrebried species, considered a nomen nudum, found in Kazakhstan, know now as Otodus sp. by the most paleontologists. == See also ==