Giant prehistoric shark remains a mystery — but it may be even more terrifying than previously thought

CHICAGO, Ill. — The megalodon — the biggest shark in history — might have been even bigger and more terrifying than scientists thought. However, it’s actual size remains a mystery after 15 million years.

Researchers from DePaul University say every proposed image of the gigantic predator sits in the realm of fantasy. The truth is scientists are still trying to piece together what the beast looked like and how big it really was.

Recent estimates suggest the creature measured up to 65 feet in length and weighed more than 50 tons. However, since researchers have only found the shark’s teeth and jaws, they can’t definitively determine the beast’s actual shape.

“This new study shows that there are currently no scientific means to support or refute the accuracy of any of the previously published body forms of O. megalodon,” says lead author Phillip Sternes, a PhD candidate at the University of California, Riverside, in a media release.

‘Large tooth’ roamed the oceans for millions of years

The earliest fossils of the megalodon date back over 20 million years. The enormous fish continued to dominate the oceans until going extinct about 3.6 million years ago. Its seven-inch teeth and the odd vertebrae are all that remain. Cartilage rarely survives fossilization. Without a complete skeleton, reconstructions are only speculative. In fact, megalodon translates to “large tooth.”

“The study may appear to be a step backward in science, but the continued mystery makes paleontology, the study of prehistoric life, a fascinating and exciting scientific field,” says co-author Professor Kenshu Shimada from DePaul University.

The analysis in the journal Historical Biology provides new insight into our current understanding of the megalodon’s body shape. Traditionally, the modern Great White shark is the common model for this prehistoric beast, which belongs to a group known as lamnids.

They also include the mako, porbeagle, and salmon shark, which are partially warm-blooded — enabling them to be active predators. Megalodon is also believed to have been warm-blooded. Scientists use a technique called two-dimensional geometric shape analyses to infer its shape. However, the approach cannot differentiate between modern, cold-blooded sharks called Lamniformes and their warm-blooded peers.

“Although it is still possible that O. megalodon could have resembled the modern great white shark or lamnids, our results suggest that the two-dimensional approach does not necessarily decisively allow the body form reconstruction for O. megalodon,” says co-author Jake Wood, a graduate student in Prof. Shimada’s lab.

Could megalodon be alive today?

With its large, serrated teeth, megalodon likely dined on meat — including whales, large fish, and other sharks.

“Any meaningful discussion about the body form of O. megalodon would require the discovery of at least one complete, or nearly complete, skeleton of the species in the fossil record,” Wood says.

Although some have suggested the megalodon could still be alive today — the premise of 2018 movie “The Meg” — experts say that is impossible. As a warm-water species, it would not be able to survive in the cold waters of the deep.

“The fact that we still don’t know exactly how O. megalodon looked keeps our imagination going,” Shimada concludes. “This is exactly why the science of paleontology continues to be an exciting academic field. We’ll continue looking for more clues in the fossil record.”

South West News Service writer Mark Waghorn contributed to this report.