Otodus megalodon

*Otodus megalodon*, informally known as the megatooth shark, is an otodontid mackerel shark from the Miocene-Pliocene of the entire world. It was named in 1843 by Louis Agassiz. It was the biggest fish to exist, and by extension, the largest active predator; as well as this, its teeth were once thought to be the tongue stones of large dragons.

## Physiology

O.megalodon most likely resembled a giant great white shark. It was a large fish with a torpedo-shaped body, triangular pectoral (arm) and dorsal (back) fins, a crescent-shaped caudal (tail) fin, a mid-sized head with a pointy, conical nose and large jaws, and 5 gills located near the head on each side of its body. Its body would have been covered in scaly skin.

## Diet

O.megalodon was a predator, preying on small whales, seals, dugongs, turtles, and smaller sharks. Its large, triangular teeth had knife-like serrations from front to back, and were used to slice the flesh of larger prey.

## Ecology

O.megalodon may have been one of the most efficient epipelagic sea predators to have ever existed, equaling (if not rivaling) giant Mesozoic marine reptiles such as Mosasaurus and Kronosaurus in terms of predatory aptitude; it had a great sense of smell (allowing it to sense the smell of blood from a far distance), a wide gape, robust, razor-sharp teeth, massive jaws capable of exerting a tremendous force when biting down on prey (allowing it to crush their bones), and a lateral line that could detect movements in the water. In order to hunt small prey (which it did a vast majority of the time), it would wait for them to surface for air right before ramming into them at great speeds, incapacitating them and allowing the shark to finish them off. As well as this, the presence of O.megalodon in the Neogene seas impacted marine communities and food chains a great deal, as fossil evidence indicates its emergence correlated with the massive diversification of whales; as well as this, in response to competition with it, macropredatory toothed whales either became pod hunters or reached gigantic sizes (an example of the latter would be Livyatan). Along with this, similarly to great white sharks, O.megalodon may have given birth to live young in warm water coastal nurseries, where juveniles would swim around and snack on fish; after they grew to adulthood, they left the nursery, moved into deeper waters, and started to incorporate whales into their diet.

## In popular culture

Since its discovery, O.megalodon has become one of the most famous prehistoric sea creatures; in fact, it has become so popular that it gets as much hype as the giant theropod dinosaur Tyrannosaurus. Now, it frequently appears in the media, where it is often oversized to a length of 30 meters and portrayed as a marauding brute willing to chase people over long distances in an attempt to eat them; in slightly more egregious cases, it will either be shown as still living in the Mariana Trench (even though it was not built for living in the deep, and it went extinct 3.5 million years ago due to the lack of small whales to feed on) or will appear in Mesozoic oceans, chomping on dinosaurs and marine reptiles alike (even though it appeared 43 million years after the dinosaurs died). Documentaries tend to be unsteady about their portrayal of the massive shark, with most documentaries like *Chased by Sea Monsters* or *Prehistoric Predators* portraying it in a less persistent and more animalistic light; however, one egregious Shark Week documentary by Discovery Channel, *Megalodon: The Monster Shark Lives*, has managed to convince many conspiracy theorists and ignorant movie-goers that the prehistoric leviathan still continues to swim around in the abyss by using scrappy evidence such as anecdotal statements by unwitting civilians or misidentified whale globsters, and thus, has tarred Discovery Channel's and Shark Week's reputation among more critical thinkers.