Ancient megalodon sharks may have been at least 2 meters long when they were born – and they may have grown so large that they ate unhatched eggs in the uterus.
Kenshu Shimada of DePaul University in Chicago and his colleagues examined one Otodus Megalodon Fossil extracted from 15 million year old rock in the 1860s and now housed in the Royal Belgian Institute of Natural Sciences. By examining the shark’s vertebrae, they were able to estimate its size at different stages of life.
“Megalodon’s total size at birth was about two meters, which suggests that, like all lamniform sharks today, it must have given birth alive,” says Shimada.
Similar to how a tree trunk has annual growth rings, the shark eddies have growth bands. By counting these, Shimada and his team suggest that this specimen megalodon died at the age of 46.
Previous studies in Ö. Megalodon relied on evidence from his teeth to estimate height. This is because teeth are often the only part of a shark that fossils because its skeleton is made up of cartilage rather than bone. Studying rare vertebral body remains is crucial to learning more about ancient sharks, says Jack Cooper of Swansea University in the UK.
The great birth size of O. Megalodon suggests that the young sharks, like many sharks today, ate unhatched eggs in the uterus in order to survive – a phenomenon known as intrauterine cannibalism.
“The result is that few puppies survive and develop, but any of them can be large at birth, which gives [them] An advantage for already large predators, ”says Shimada.
While new research has provided information about the pattern of growth between birth and middle age, little is known about megalodon growth later in life.