A new study shows that the height of the legendary gigantic megalodon or megatooth shark, which is around 15 meters long, is actually unusually large compared to the height of its relatives. Formally called Otodus megalodonThe fossil shark, which lived almost worldwide about 15 to 3.6 million years ago, is getting a fresh look at the importance of its height in the shark world, based on a new study published in the international journal Historical biology.
Otodus megalodon is often portrayed as an oversized, monstrous shark in novels and films such as the science fiction thriller “The Meg” from 2018. However, it is known that the scientifically justifiable maximum possible height for the species is currently around 50 feet (15 meters; not 16 meters or more in previous studies). Even so, it’s still an impressively large shark, and the new study sheds light on just how uniquely gigantic the shark was compared to other sharks, noted Kenshu Shimada, a paleobiologist at DePaul University in Chicago and lead author of the study.
Schematic representation of the distribution of the maximum possible sizes of all known 70 non-planktivorous genera (groups) in the shark order Lamniformes, consisting of modern (gray) and extinct (black; with hypothetical silhouettes) members and in comparison to an average adult human (in red) as a scale. Note the unusually large size of the legendary megatooth shark Otodus megalodon (15 meters or 50 feet) and the fact that in the Cenozoic Era (after the age of the dinosaurs, including today) more lamniform genera reached larger sizes than the Mesozoic Era (Age of the Dinosaurs ) Era. Photo credit: Kenshu Shimada, DePaul University
Otodus megalodon belongs to the shark group of lamniforms with a rich fossil record, but the biology of extinct forms is little known as these cartilaginous fish are mostly known only from their teeth. The study used measurements taken on samples of all 13 species of today’s macrophagic (non-planktivorous) lamniforms to generate functions that would allow an estimate of the body, jaw, and dentition lengths of extinct macrophagic lamniforms from their teeth. These quantitative functions enabled researchers to study the body size distribution of all known macrophage lamniform genera over geological time.
The paleobiologist Kenshu Shimada from DePaul University is holding a tooth of an extinct shark Otodus megalodon or the so-called “Meg” or Megatooth shark. Photo credit: DePaul University / Jeff Carrion
The study shows that O. Megalodon Reaching at least 14.1 meters is really an outlier, as virtually all other macrophage sharks, including extinct forms, have a general size limit of 7 meters. and few plankton-eating sharks, such as the whale shark and basking shark, were equivalent or close to size. The study also shows that in the Cenozoic (post-dinosaur age, including today) more lamniform lines reached sizes larger than that Mesozoic Era (age of dinosaurs).
It has been suggested previously that warmblood led to the gigantism (20 feet or more than 6 meters) in several lamniform lines. The new study suggests their live reproductive strategy with a unique cannibalistic egg-eating behavior to feed large-sized early-hatched embryos within their mother to be another possible cause of the common development of the gigantism attained by lamniform sharks.
Understanding the body size of extinct organisms is important in the context of ecology and evolution. “Lamniform sharks have been major carnivores in the oceans since the age of the dinosaurs, so it is reasonable to say that they must have played an important role in shaping the marine ecosystems known today,” said Shimada.
“This is compelling evidence of the truly extraordinary size of the megalodon,” remarked co-author Michael Griffiths, professor of environmental science at William Paterson University in Wayne, New Jersey. Co-author Martin Becker, also a professor of environmental science at William Paterson University, added, “This work represents a critical advance in our understanding of the evolution of this ocean liner.”
The new study “Body, jaw and bit lengths of macrophage lamniform sharks and the development of body size in lamniformes with special consideration of the gigantism of the megatooth shark outside the scale” Otodus megalodon, ”Appears in the upcoming issue of Historical biology.
Reference: “Body, jaw and bit lengths of macrophage lamniform sharks and development of body size in lamniformes with special consideration of the gigantism of the megatooth shark Otodus megalodon outside of scale” by Kenshu Shimada, Martin A. Becker and Michael L. Griffiths, 4 October 2020, Historical biology.
DOI: 10.1080 / 08912963.2020.1812598
