Sea Monsters

• Otodus megalodon, the biggest shark of all time, has long captured the imaginations of palaeontologists and the public alike.
• As big as human hands and serrated like kitchen knives, they were used for cutting down whales unlucky enough to encounter these sharks.
• This gigantic predator has been further propelled into the limelight through popular culture.
• I am now, 20 years later, a practising palaeobiologist specialising in fossil sharks and my most well-known work revolves around none other than megalodon.

Megalodon biology and cinematic representation

• Nitrogen isotope values from megalodon are exceptionally high, indicating it was higher up the food chain than any living marine predator.
• In short, the megalodon was the most apex of ocean predators.
• Mesothermy enhances swimming speeds, allowing a megalodon to travel faster and further, increasing its chances of finding prey.
• This active lifestyle would have forced megalodon to eat more food – around 98,000 kcal every day – to justify its size.
• And it should make for a very cool moment of cinematic absurdity.

A better story for sharks

• It caused the spread of great white sharks, for example, and allowed whales to get even bigger because there were no more giant sharks to fear.
• Unfortunately, media depictions like this can drive bizarre conspiracy theories that megalodons are somehow still alive.
• Sharks continue to be portrayed negatively in the wider media, despite up to a third of today’s sharks being threatened with extinction.
• We kill as many as 100 million sharks every year and the largest ones are at particular risk.