A groundbreaking study by researchers at Bristol University found that the evolution of the teeth of the prehistoric basking shark Megalodon and its relatives was a by-product of growth rather than an adjustment to new eating habits.
The iconic extinct megalodon was the largest shark to ever roam the seas. Its name means "big tooth" and refers to its massive teeth, which are the most common fossil remains of the species. They are broad and triangular, nothing like the curved, blade-like teeth of Megalodon's closest relatives.
It has traditionally been believed that the differences in tooth shape that occur in this group of basking sharks reflected a change in diet. While the oldest relatives likely used their teeth to pierce small and fast-moving prey such as fish, megalodons most likely used them to bite off large pieces of marine mammal meat or to dismember such prey with strong side-shaking heads.
The new study published today in the journal Scientific reports, Scientists used computational tools to understand how these Megatooth sharks' teeth worked while they were being fed.
Antonio Ballell, PhD student at the University of Bristol's School of Earth Sciences, said: "We used technical techniques to digitally simulate how different tooth shapes deal with bite forces and loads resulting from lateral head movements.
"This method, known as finite element analysis, has already been used to understand how resistant different biological structures are under certain forces.
“We expected megalodon teeth to withstand forces better than those of its older and smaller relatives. When we removed tooth size from the simulations, we surprisingly restored the opposite pattern: Megalodon teeth are relatively weaker than the most delicate teeth of others Megatooth sharks. "
Dr. Humberto Ferrón, postdoctoral fellow and co-author of the study, said, "Our results seem to contradict traditional functional interpretations of the dentition of this group of basking sharks. We believe that other biological processes may be responsible for the evolutionary change in their dentition.
"For example, changes in tooth shape that occurred from the older, smaller species to those of the newer, larger forms such as megalodons are very similar to those observed during the growth of megalodons.
"That said, juvenile Megalodon individuals have teeth that resemble those of older Megatooth Sharks. Rather than specializing in feeding, we believe that acquiring their gigantic size was responsible for the development of Megalodon's peculiar teeth."