An “enormous” prehistoric shark has been crowned the “predator of predators” for being at the peak of the marine food chain, in a new study.
Princeton University researchers carried out a study where they ranked predators through history and it was the Megalodon shark that came out on top.
What was most surprising about Megalodons was their sheer size.
They are a type of mackerel shark that is now extinct but were around from around 23 to 3.6 million years ago.
But at 65 feet long they were more than a match for other predators around at the time - and at least three times larger than the largest modern great white sharks.
"We're used to thinking of the largest species - blue whales, whale sharks, even elephants, and diplodocuses, as filter feeders or herbivores, not predators," study author Emma Kast said.
"But Megalodon and the other megatooth sharks were genuinely enormous carnivores that ate other predators, and Meg went extinct only a few million years ago."
The fact they were so big and that they would eat other predators has put the Megalodon at the “highest trophic level” i.e. the highest level of the food chain.
This is reinforced by the fact that Megalodons had no known predator which meant they reigned supreme.
"Ocean food webs do tend to be longer than the grass-deer-wolf food chain of land animals because you start with such small organisms," said Dr Kast.
"To reach the trophic levels we’re measuring in these megatooth sharks, we don’t just need to add one trophic level, one apex predator on top of the marine food chain, we need to add several onto the top of the modern marine food web."
In order to study the prehistoric marine food web, the researchers used a special technique to measure the nitrogen isotopes in the sharks' teeth.
The more nitrogen-15 that is detected in a species, the higher it lies on the food chain.
Until now, scientists have not been able to measure the tiny amounts of nitrogen preserved in the enamel layer of these extinct shark teeth.
Zixuan (Crystal) Rao, a graduate student and a co-author of the paper said: "We have a series of shark teeth from different time periods, and we were able to trace their trophic level versus their size".
One way that certain animals reach a higher trophic level is by cannibalism and several lines of evidence point to that in both megatooth sharks and other prehistoric marine predators.
