The Megalodon, one of the most fearsome sharks that ever lived, was not a cold-blooded killer as previously thought, but a warm-blooded animal that could regulate its body temperature, a new study has revealed.
Scientists from the US and Australia analyzed the fossilized teeth of the megalodon, which went extinct about 3.6 million years ago, and found that it had a body temperature that was about 7°C warmer than the surrounding water.
This suggests that the megalodon belonged to a group of sharks called mackerel sharks, which include modern great white and thresher sharks, that can keep the temperature of all or parts of their bodies somewhat warmer than the water around them.
Being warm-blooded may have been one of the key factors that enabled the megalodon to grow up to 50 feet (15 meters) long and become a dominant predator in the ancient oceans.
“A large body promotes efficiency in prey capture with wider spatial coverage, but it requires a lot of energy to maintain,” said Kenshu Shimada, a professor of paleobiology at DePaul University in Chicago and the senior author of the study.
“Warm-bloodedness is advantageous because it allows an animal to have a more active lifestyle, such as being able to sustain long-distance swimming or fast swimming,” he added.
However, the same trait that gave the megalodon an edge over its rivals may have also contributed to its downfall, as it faced environmental changes and competition from other predators.
“Studying the driving factors behind the extinction of a highly successful predatory shark like megalodon can provide insight into the vulnerability of large marine predators in modern ocean ecosystems experiencing the effects of ongoing climate change,” said Robert Eagle, an assistant professor of atmospheric and oceanic sciences at UCLA and the lead researcher of the study.
The study, published in Proceedings of the National Academy of Sciences, suggests that the megalodon’s high energy demand for staying warm made it more susceptible to food scarcity and shifting food-chain dynamics.
The availability of its primary food source, baleen whales, decreased as the Earth entered an ice age, while the numbers of its competitors, such as great white sharks, increased.
Other factors that may have played a role in the megalodon’s extinction include climate cooling, sea level drop, and possibly a supernova that occurred about 2.6 million years ago.
The radiation from this cosmic event could have damaged Earth’s ozone layer and triggered a mass extinction of marine life, according to some scientists.
The megalodon’s extinction may have been a complex and multifaceted process that involved both biological and environmental factors.
The new study sheds light on the warm-blooded nature of this ancient shark and its implications for its evolution and extinction.
Relevant articles:
– New analysis of tooth minerals confirms megalodon shark was warm-blooded, University of California, Los Angeles, June 26, 2023
– Scientists find new clue in what led to megalodon’s demise, CNN, July 3, 2023
– Megalodon was a warm-blooded killer, but that may have doomed it to extinction, Live Science, June 26, 2023
– Megalodon was a truly vicious killer, but not a cold-blooded one, Earth.com, June 28, 2023