About 23 to 3.6 million years ago, a shark roughly three times the size of the great white shark (Carcharodon carcharias)—arguably made famous in the blockbuster 1975 movie JAWS—roamed the oceans of the world. The megalodon (Otodus megalodon or O.megalodon) is believed to be the largest shark that ever has lived, measuring 34 to 66 feet and weighed upwards of 135,716 pounds. That’s about the weight of the Space Shuttle Endeavour.
New research published this week in the journal Science Advances suggests that the sizable shark was not only the apex predator of its day, but a “transoceanic super-predator” that could travel thousands of miles across oceans on long migrations, even faster than modern-day sharks. The research by Swansea University PhD student Jack Cooper, shark expert Catalina Pimiento from the Paleontological Institute and Museum at the University of Zurich, and John Hutchinson from the Royal Veterinary College shows the sharks may have eaten meals that were the size of an orca whale, consumed in an about five or more bites.
The researchers used data from an O. megoladon fossil vertebral column, various teeth, and a chondrocranium from our friend the great white shark (its closest living relative) to build out the 3D model.
“The 3D modeling of O.megalodon was only possible thanks to a rare and exceptional vertebral column specimen from Belgium: 141 vertebrae from a single shark,” said Cooper, in an e-mail to Popular Science. “It’s a one of a kind specimen that may well hold the key to further discoveries on this giant shark, having mostly been in museum storage in Brussels since the 1860s.”
Professor Hutchinson added, “Computer modeling provides us with an unprecedented ability to use exceptionally well-preserved fossils to reconstruct the entire body of extinct animals, which in turn allows estimations of biological traits from the resulting geometry. Models of this nature represent a leap in knowledge of extinct super predators such as megalodon and can then be used as a basis for future reconstruction and further research.”
The 3D model allowed the team to figure out the shark’s length, volume, and gape size. These measurements, in turn, helped them calculate its body mass, inferring swimming speed, energetic demands, and stomach volume based on the relationship between these variables and body mass in living sharks. The newly calculated swimming speed means that the shark was potentially able to swim further distances than its competitors, increasing how quickly it could migrate and eat its way around the ocean, larger like marine mammals prey included.
“Megalodon’s large body size and potential energetic demands suggest that it would need/prefer highly caloric prey, like whales. Prey encounters relate with not only preference, but also prey availability and abundance,” Pimiento added.
It is a lack of abundance that potentially drove the megalodon into extinction, roughly 3.3 million years ago, during the Pliocene epoch. A 2016 study published in the Journal of Biogeography and authored by Pimento suggests that the megalodon’s demise came not from dramatic swings in the climate, but due to a decrease its primary food source at the time (baleen whales) and increase in other predatory sharks (the great white included) and whales in the Orcinius genus.
As the prehistoric ocean’s top predator and resident globetrotter, O. megalodon’s extinction would have post major changes on global nutrient transfer and ocean food webs throughout the world.
“The extinction of this iconic giant shark likely impacted global nutrient transport and released large cetaceans from a strong predatory pressure,” said Pimiento.