The story
Otodus megalodon, the biggest meat-eating shark known, appeared in the early Miocene about 23 million years ago and lived in warm and temperate seas worldwide. Its fossil teeth, up to about 18 centimetres long on the slant, have been known since antiquity. In 1667 the Danish naturalist Nicolas Steno, dissecting a shark head, recognized that the so-called tongue stones found in rocks were petrified shark teeth. Because the cartilage skeleton rarely fossilizes, size estimates rest on teeth and a few vertebral columns, and they range from about 14 to 18 metres, with recent studies leaning towards about 15 to 16 metres.
Megalodon is placed in an extinct family of mackerel sharks, and it is not a giant great white, as once assumed. Its growth was fuelled by abundant whales and seals in the Miocene seas. Bite marks and broken teeth on whale ribs and flippers show it attacked large prey, and its estimated bite force of over 100,000 newtons is among the strongest of any animal. In 2010 Catalina Pimiento and colleagues found a nursery area in Panama's fossil beds, where juveniles lived in shallow waters.
It was a top predator for nearly 20 million years. Its decline in the Pliocene is discussed in a separate entry, and its fossil teeth are still found in Atlantic and Pacific coastal beds.
Why it mattered
- Megalodon was the apex predator of Miocene seas and a major force shaping early whale evolution.
- Its teeth, abundant as fossils, give researchers a record of ocean temperatures and shark populations.
- Its disappearance marks a major turnover in marine predators.
Community notes
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