By combining cutting-edge digital modeling with analysis of a rare, one-of-a-kind fossil, scientists have pieced together the first 3D reconstruction of the Megadolon, the largest shark to ever live. From this new 3D model the scientists were able to gain fascinating new insights into the behaviors of this terrifying prehistoric predator, including a diet that included blubber-rich whales measuring up to eight meters (26-ft) long.
Thankfully for surfers and ocean swimmers, the Megalodon shark went extinct around three million years ago. Much of what we do know about this fearsome creature comes from studies of its massive teeth, each around the size of a human hand. Like the sharks of today, its skeleton is made of cartilage which unfortunately doesn’t tend to hold up too well in the ocean environment.
“Shark teeth are common fossils because of their hard composition which allows them to remain well preserved,” says first author of the new study Jack Cooper, PhD student at Swansea University. “However, their skeletons are made of cartilage, so they rarely fossilize.’
Researchers have been able to shed light on the lifestyle and physical form of the Megaoldon through isotope analysis of its teeth, for example, or analyzing its close relatives to gain an idea of its size. Cooper and his co-authors were able to expand on these efforts by studying a rare, fossilized vertebral column belonging to a Megadolon that died off the coast of Belgium around 18 million years ago.
The scientists measured and scanned each of the vertebra, and reconstructed the entire vertebral column, which was then combined with a 3D scan of a set of Megadolon teeth. From this, the team was able to use advanced 3D modeling and scans of great white sharks to build out the flesh around the skeleton, completing what is billed as the first 3D model of the Megadolon.
“Weight is one of the most important traits of any animal,” said co-author John Hutchinson, professor at the Royal Veterinary College in the UK. “For extinct animals we can estimate the body mass with modern 3D digital modeling methods and then establish the relationship between mass and other biological properties such as speed and energy usage.”
The reconstructed Megadolon was 16 m (52 ft) long, weighed more than 61 tons and moved through the water at 1.4 meters per second (4.6 ft/s). With a stomach volume of almost 10,000 liters (2,640 gal), the shark required around 98,000 kilocalories of sustenance each day. The scientists say that smaller prey measuring 3 to 6 m (10 to 20 ft) could be eaten in just a few bites, while larger prey of around 8 m, the same size as the modern orca, could be consumed in around five.
Based on modeling of foraging and energy use, the scientists say the Megadolon would have subsisted on calorie-rich blubber of whales. The optimal model for prey encounters found that eating a single eight-meter-long whale would have enabled the Megadolon to travel thousands of miles across the seas, not needing to eat again until two months later.
“These results suggest that this giant shark was a trans-oceanic super-apex predator,” says Catalina Pimiento, Professor at the University of Zurich and senior author of the study. “The extinction of this iconic giant shark likely impacted global nutrient transport and released large cetaceans from a strong predatory pressure.”
The scientists see this as a leap in what we know about Megadolon and the way megafauna shaped the marine ecosystem. This new understanding of its physical features and behavior can also guide future reconstruction efforts and research into this menacing ancient predator.
The research was published in the journal Science Advances.
Source: University of Zurich