Scientists Reconstruct Body Dimensions of Megalodon

A 16-m- (52.5-foot) long megalodon had a head 4.65 m (15.3 feet) long, a dorsal fin 1.62 m (5.3 feet) tall and a tail 3.85 m (9.4 feet) high, according to a study led by researchers from the University of Bristol and Swansea University.

The megalodon (Otodus, or Carcharocles, megalodon), the largest shark that ever lived on Earth, ruled the oceans between 23 and 2.6 million years ago, during the Early Miocene to the Pliocene.

This prehistoric monster was a top-level predator that fed on whales and other marine mammals.

It had a cartilaginous skeleton and was therefore poorly preserved with exception of its teeth, but paleontologists believe that it looked a lot like the extant great white shark (Carcharodon carcharias), only far larger.

University of Bristol researcher Jack Cooper and colleagues used a number of mathematical methods to pin down the size and proportions of the megalodon, by making close comparisons to five ecologically and physiologically similar extant species: the great white shark, the shortfin mako shark (Isurus oxyrinchus), the longfin mako shark (Isurus paucus), the salmon shark (Lamna ditropis) and the porbeagle (Lamna nasus).

“The megalodon is not a direct ancestor of the great white but is equally related to other macropredatory sharks such as the makos, salmon shark and porbeagle shark, as well as the great white,” said corresponding author Dr. Catalina Pimiento, a researcher from Swansea University, the Smithsonian Tropical Research Institution and the Paleontological Institute and Museum at the University of Zurich.

“We pooled detailed measurements of all five to make predictions about the megalodon.”

“Before we could do anything, we had to test whether these five modern sharks changed proportions as they grew up,” said senior author Professor Mike Benton, a paleontologist at the University of Bristol.

“If, for example, they had been like humans, where babies have big heads and short legs, we would have had some difficulties in projecting the adult proportions for such a huge extinct shark.”

“But we were surprised, and relieved, to discover that in fact that the babies of all these modern predatory sharks start out as little adults, and they don’t change in proportion as they get larger.”

“This means we could simply take the growth curves of the five modern forms and project the overall shape as they get larger and larger — right up to a body length of 16 m,” added Jack Cooper, a Ph.D. student at Swansea University.

The team’s results suggest that a 16-m-long megalodon likely had a head round 4.65 m long, a dorsal fin approximately 1.62 m tall and a tail around 3.85 m high.

This means an adult human could stand on the back of this shark and would be about the same height as the dorsal fin.

“The reconstruction of the size of megalodon body parts represents a fundamental step towards a better understanding of the physiology of this giant, and the intrinsic factors that may have made it prone to extinction,” the researchers said.

The study appears in the journal Scientific Reports.

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J.A. Cooper et al. 2020. Body dimensions of the extinct giant shark Otodus megalodon: a 2D reconstruction. Sci Rep 10, 14596; doi: 10.1038/s41598-020-71387-y

Source: http://www.sci-news.com/