Megalodon sharks whose newborns were larger than an adult human.
The new research made by Kenshu Shimada, a professor of paleobiology at DePaul University in Chicago, has shown us that newborn megalodon sharks started life at about 2 meters long. This means that these “baby sharks” were larger than most adult humans.
The Megalodon shark or Otodus megalodon is a gigantic extinct species that lived in tropical-temperature regions more than 2, 5 million years ago.
The fossil records of Megalodon shark are often limited to its teeth, however; Kenshu Shimada with his colleagues used extra evidence: megalodon vertebrae. The scientists examined archival photos of 15 vertebrae, each with a specific “centrum number”, that had no bearing in terms of its anatomical position. Then, they used micro-computed tomography to study the band pattern along with the sagittal selection of three specific vertebrae.
As a result, they received the information showing all three vertebrae had 46 growth bands, which is, according to the study, believed to be the indicator of animal’s age in years, much as the rings of a tree but for fish species. The predator is estimated to be 9 meters long at its death, the size of the bands shows the predator’s growth rate of about 16 cm per year. So, taking into account the aforesaid information, Shimada with his team have calculated the approximate size of a newborn megalodon shark, it reveals that such neonates would have been about 2 meters long at the beginning of their life.
Furthermore, the scientists believe that these species had an ovoviviparous (or aplacental viviparity) reproductive mode with a cannibalism behaviour in the form of oophagy. This may have helped neonates to reach such length at their birth.
Story Sources:
- “Ontogenetic growth pattern of the extinct megatooth shark Otodus megalodon — implications for its reproductive biology, development, and life expectancy”. Originally written by Kenshu Shimada. Published online January 11, 2021. DOI: 10.1080/08912963.2020.1861608.
