Scientists from Zurich University have proposed the largest shark that ever lived became extinct due to a lack of prey and increased competition from predators.
Carcharocles megalodon lived between 2.6m and 28m years ago and could grow to up to 18 metres in length. It weighed up to 100 tonnes and fed on small whales. The scientists’ new theory moves away from the previous reasoning behind their extinction – climate change.
Dr Catalina Pimiento, lead author from Zurich University said: “We were not able to ascertain any direct link between the extinction of C. megalodon and the global fluctuations in temperatures during this time. Changing climatic conditions do not appear to have had any influence on the population density and range of the giant sharks.”
Approximately 200 megalodon records from museums and databases were analysed by the researchers. They found up to 16 million years ago, the giant predators were found mainly in the Northern Hemisphere, near Europe, America and the Indian Ocean but then travelled further into the South American, Asian and Australian coasts over time. C. megalodon’s population numbers peaked during the middle of the Miocene epoch with the species becoming extinct in the Pliocene.
Number of C. megalodon did not decline during colder periods of their lifetime and vice versa. However, when the amount of territory the giant shark occupied shrunk, a large number of smaller marine mammal species disappeared, said researchers. In addition to this, new predators emerged, such as the ancestors of the killer whale and great white shark, meaning increased competition for the remaining food sources.
The research was published in the Journal of Biogeography.