Megalodon, Otodus megalodon

Introduction

Otodus megalodon, meaning 'giant tooth', is an extinct species of mackerel shark that lived approximately 23 to 3.6 million years ago. The skeletons of sharks, including O. megalodon, are rarely well-preserved due to its cartilaginous structure. Unlike their skeletons, shark teeth are made of resistant dentine and enamel and are commonly preserved in the fossil record.

Identification

The megalodon is the largest shark to have ever lived. Comparisons between the tooth shapes of O. megalodon and today’s Great White Shark (Carcharodon carcharias), has previously suggested to scientists that the two had approximately comparable body outlines. Calculating from the proportions of living sharks and their teeth, scientists have used fossils to estimate that the body length of an adult O. megalodon ranged between 10 to 20 meters - about three times the size of the Great White Shark (Cooper et al. 2020; Pimiento and Balk 2015).

Despite the close comparison to the modern Great White Shark it appears, based on the limited body fossil material we do have, that O. megalodon is not closely related, belonging to a different family.

Habitat

Remains of megalodon fossils have been found across Europe, Africa, the United States of America and Australia, suggesting that the species occupied all of the oceans, except for polar areas. Juvenile megalodon likely inhabited warm nearshore regions for their abundance of food resources and safety from predators (Pimiento et al. 2010), whereas the adults likely preferred open ocean environments.

Feeding and diet

The fossil record indicates that O. megalodon was an apex predator, consuming a broad spectrum of aquatic animals. Evidence of megalodon bite marks have been found on the preserved bones of many mammalian species, including dolphins, small whales, seals and sirenians. Similar bite marks have also been recorded on the remains of sea turtles, fish, and even other sharks (Collareta et al. 2017).