The giant shark of prehistoric times gives birth to young ca …

he The giant prehistoric megalodon shark, extinct millions of years ago, continues to generate interest in the scientific community. So much so that two recent studies have revealed two new characteristics of the mythical animal: she gave birth to cannibalistic puppies two meters long and the evolution of their teeth was a consequence of their size, not an adaptation to new eating habits.

The first study, which delved into the reproductive biology, growth and life expectancy of Megalodon Otodus megalodon-, showed that the animal he gave birth to youngs larger than most adult humans, who probably grew up eating unhatched eggs in the womb.

The research, published in the scientific journal Historical biology, indicated that “from its birth, the megalodon was already a big fish”. This was explained by Kenshu Shimada, a paleobiologist at DePaul University in Chicago and lead author of the study. “As one of the largest carnivores to ever exist on Earth, deciphering these parameters of Megalodon growth is essential to understanding the role that large carnivores play in the context of changing marine ecosystems,” a- he declared.

The researchers used a computed tomography technique to examine incremental growth bands supposedly recorded annually (analogous to tree rings) in a Megalodon vertebral specimen housed at the Royal Belgian Institute of Natural Sciences in Brussels. Measuring up to 15 centimeters in diameter, the vertebrae were previously estimated to originate from an individual around 30 feet in length, based on comparisons with the vertebrae of modern great white sharks.

CT images revealed the vertebrae had 46 growth bands, meaning the 9-meter Megalodon fossil died at the age of 46. By calculating the length of your body when each band was formed, Research suggested the shark’s size at birth was around two meters long, a finding that indicated Megalodon had given birth to perhaps the largest baby sharks in the world.

These data also reflect that, like all current lamniform sharks, The embryonic megalodon grew inside its mother feeding on unhatched eggs in the uterus, a practice known as oophagy, a form of intrauterine cannibalism.

“The results of this work shed light on Megalodon’s life story, not only on how he grew up, but also how his embryos developed, how he gave birth and how long he was able to live. », Clarified co-author Becker.

The teeth

The iconic Megalodon, which populated the seas around 15 million years ago, was the largest shark in existence. Its name translates to “big tooth”, in reference to its enormous teeth, which represent the most abundant fossil remains of the species. They are wide and triangular, very different from the curved, blade-like teeth of Megalodon’s closest relatives.

Until now, the differences in tooth shape seen in this group of giant sharks have been thought to reflect a change in diet. However, A recent study by researchers at the University of Bristol indicated that the evolution of the megalodon’s teeth was a consequence of its size rather than an adaptation to new eating habits.

While older parents likely used their teeth to pierce small, fast prey such as fish, it is highly likely that Megalodon used them to bite into large pieces of marine mammal meat or dismember these prey with powerful sideways movements. of the Head.

In the new study published in the journal Scientific reports, scientists used computer tools to understand how the teeth of these sharks worked during feeding.

Antonio Ballell, from the School of Earth Sciences at the University of Bristol, said: “We apply engineering techniques to digitally simulate how different shapes of teeth deal with bite forces and loads resulting from lateral movements of the teeth. the head. “.

“We were hoping to find that Megalodon’s teeth could withstand the forces better than those of their larger and smaller parents. Surprisingly, when we removed the tooth size from the simulations, we found the reverse pattern: Megalodon teeth are relatively weaker than the more graceful teeth of other medadent sharks“he added.

Dr Humberto Ferrón, co-author of the study, said: “Our results may appear contrary to traditional functional interpretations of the dentitions of this group of giant sharks. We believe that other biological processes may be responsible for the evolutionary change of their teeth. “

Simply put, young megalodons have teeth that resemble those of older megadent sharks. So instead of specializing in feeding, we believe that the acquisition of its gigantic size was responsible for the evolution of the particular teeth of Megalodon», He concluded.