The huge extinct shark types referred to as the megalodon has actually caught the interest of researchers and the public alike, even motivating the 2018 hit movie The MegThe types lived some 3.6 million years earlier, and no total skeleton has actually yet been discovered. There has actually been substantial dispute amongst paleobiologists about megalodon’s size, body shape, and swimming speed, amongst other qualities.

While some scientists have actually compared megalodon to an enormous variation of the stocky fantastic white shark, others think the types had a more slim body shape. A brand-new paper released in the journal Palaeontologia Electronica reinforces the latter perspective, likewise reasoning about the megalodon’s body mass, swimming speed (based upon hydrodynamic concepts), and development patterns.

As formerly reported, the biggest shark alive today, rising to 20 meters long, is the whale shark, a sedate filter feeder. As just recently as 4 million years back, nevertheless, sharks of that scale most likely consisted of the fast-moving predator megalodon (officially Otodus megalodon. Due to insufficient fossil information, we’re not totally sure how big megalodon were and can just make reasonings based upon a few of their living family members.

Thanks to research study released in 2023 on its fossilized teeth, we’re now relatively positive that megalodon shared something else with these family members: it wasn’t completely cold-blooded and kept its body temperature level above that of the surrounding ocean. The majority of sharks, like many fish, are ectothermic, indicating that their body temperature levels match those of the surrounding water. A handful of types, part of a group called mackerel sharks, are endothermic: They have a customized pattern of blood flow that assists maintain some of the heat their muscles produce. This allows them to keep some body parts at a greater temperature level than their environments.

Of specific importance to this newest paper is a 2022 research study by Jack Cooper of Swansea University in the UK and his co-authors. In 2020, the group rebuilded a 2D design of the megalodon, basing the measurements on comparable existing shark types. The scientists followed up in 2022 with a rebuilt 3D design, theorizing the measurements from a megalodon specimen (a vertebral column) in Belgium. Cooper concluded that a megalodon would have been a stocky, effective shark– determining some 52 feet (16 meters) in length with a body mass of 67.86 lots– able to carry out bursts of high speed to attack victim, just like the considerably smaller sized excellent white shark.

Not everybody concurred, nevertheless, Last year, a group of 26 shark specialists led by Kenshu Shimada, a paleobiologist at DePaul University, additional challenged the fantastic white shark contrast, arguing that the supersized animal’s body was more slim and perhaps even longer than scientists formerly believed. The group concluded that based upon the spine, the mix of a terrific white develop with the megalodon’s a lot longer length would have just shown too troublesome.

A fresh method

Now Shimada is back with a fresh analysis, using a brand-new technique that he states offers independent lines of proof for the megalodon’s slim construct. “Our new study does not use the modern great white shark as a model, but rather simply asks, ‘How long were the head and tail based on the trunk [length] represented by the fossil vertebral column?’ using the general body plan seen collectively in living and fossil sharks,” Shimada informed Ars.

Shimada and his co-authors determined the percentages of 145 contemporary and 20 extinct types of shark, especially the head, trunk, and tail relative to overall body length. Megalodon was represented by a Belgian vertebral specimen. The biggest vertebra because specimen determined 15.5 centimeters (6 inches) in size, although there are other megalodon vertebrae in Denmark, for instance, with sizes as much as 23 centimeters (9 inches).

Based upon their analysis, Shimada et al concluded that, since the trunk area of the Belgian specimen determined 11 meters, the head and tail were most likely about 1.8 meters (6 feet) and 3.6 meters (12 feet) long, respectively, with an overall body length of 16.4 meters (54 feet) for this especially specimen. That indicates the Danish megalodon specimens might have been as long as 24.3 meters (80 feet). When it comes to body shape, taking the brand-new length approximates into account, the lemon shark seems the closest modern-day analogue. “However, the exact position and shape of practically all the fins remain uncertain,” Shimada warned. “We are only talking about the main part of the body.”

The group likewise discovered that a 24.3-meter-long megalodon would have weighed 94 heaps with an approximated swimming speed of 2.1– 3.5 kph (1.3– 2.2 miles per hour ). They likewise studied development patterns obvious in the Belgian vertebrae, concluding that the megalodon would offer live birth which the babies would be in between 3.6 to 3.9 meters(12– 13 feet) long– i.e., approximately the size of a terrific white shark. The authors see this as a refutation of the hypothesis that megalodon counted on nursery locations to rear their young, given that a child megalodon would be rather efficient in searching and eliminating marine mammals based upon size alone.

In addition, “We unexpectedly unlocked the mystery of why certain aquatic vertebrates can attain gigantic sizes while others cannot,” Shimada stated. “Living gigantic sharks, such as the whale shark and basking shark, as well as many other gigantic aquatic vertebrates like whales have slender bodies because large stocky bodies are hydrodynamically inefficient for swimming.”

That’s in sharp contrast to the excellent white shark, whose stocky body ends up being even stockier as it grows. “It can be ‘large’ but cannot [get] past 7 meters (23 feet) to be ‘gigantic’ because of hydrodynamic constraints,” stated Shimada. “We also demonstrate that the modern great white shark with a stocky body hypothetically blown up to the size of megalodon would not allow it to be an efficient swimmer due to the hydrodynamic constraints, further supporting the idea that it is more likely than not that megalodon must have had a much slenderer body than the modern great white shark.”

Shimada highlighted that their analyses stay tentative however they are based upon tough information and produce helpful referral points for future research study.

An “interesting working hypothesis”

For his part, Cooper discovered a lot to like in Shimada et al.’s newest analysis. “I’d say everything presented here is interesting and presents an exciting working hypothesis but that these should also be taken with a grain of salt until they can either be empirically tested, or a complete skeleton of megalodon is found to confirm one way or the other,” Cooper informed Ars. “Generally, I appreciate the paper’s approach to its body size calculation in that it uses a lot of different shark species and doesn’t make any assumptions as to which species are the best analogues to megalodon.”

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