“Child shark” has taken on an entire new which means. New child megalodon sharks had been supersized fish bigger than most grownup people, a brand new examine suggests.
An evaluation of the expansion charges of the traditional ocean predators, which lived between about 23 million and a pair of.5 million years in the past, estimates that the sharks began life at about 2 meters lengthy, researchers report January 11 in Historic Biology.
Otodus megalodon is correct up there with Tyrannosaurus rex within the pantheon of scary extinct predators, however little is definitely identified in regards to the shark’s biology (SN: 8/10/18). Its skeleton was made from difficult-to-fossilize cartilage, so what scientists do know largely comes from fossilized enamel. For instance, paleobiologist Kenshu Shimada of DePaul College in Chicago and colleagues beforehand used megalodon enamel, in addition to these of different historic and trendy sharks, to estimate a complete grownup physique size for the fish of no less than 14 meters (SN: 10/5/20).
Within the new examine, Shimada and colleagues had an additional, uncommon piece of proof: megalodon vertebrae. Though shark skeletons are made from cartilage, the animals’ backbones can turn into hardened and strengthened by deposits of calcium salts, which might then be fossilized. These vertebrae additionally protect annual progress bands, just like the rings of a tree, displaying how the fish grew.
The researchers used an imaging approach referred to as micro-computed tomography to review three well-preserved vertebrae from one shark. These pictures revealed 46 progress bands, suggesting that this shark lived to the ripe outdated age of 46. The creature is estimated to have been about 9 meters lengthy at its demise, and the dimensions of the bands hints that the animal grew at a fee of about 16 centimeters every year. That implies that the shark would have been about 2 meters lengthy at beginning — giant sufficient for even a new child to be a fearsome foe within the seas, the scientists conclude.
Shimada’s staff has beforehand recommended that whereas in utero, megalodon sharks, like a few of their trendy cousins, might need ate up unhatched eggs within the womb. That follow might have helped the enormous fish to achieve such a big dimension even earlier than getting into the world.