A team of researchers from Princeton has recently found clear evidence that Megalodon and some of its predecessors were at the highest rung of the ancient food chain, which scientists call the "highest trophic level."

As specified in a ScienceDaily report, the researchers said that the animals' trophic signature is so high that they must have eaten other predators, as well as predators of predators in a complex food web.

The new study exhibits that prehistoric megatooth sharks, the largest sharks that ever lived, were apex predators at the highest level ever gauged.

Megatooth sharks get their names from their huge teeth, which can be larger than a human hand. The group also includes Megalodon, the biggest shark ever lived, and many other related species.

ALSO READ: Megalodon Sharks Grew Larger in Cooler Waters Than Those in Warmer Areas, Study Says


Megalodon Teeth
(Photo: Wikimedia Commons)
Researchers found clear evidence that Megalodon and some of its predecessors were at the highest rung of the ancient food chain, which scientists call the ‘highest trophic level.’


Megatooth Sharks Measured

According to 2019 Ph.D. graduate Emma Kast, the first author of the new study published in the current issue of Science Advances, "ocean food webs do tend to be longer" compared to the grass-deer-wolf food chain of land animals since one begins with such tiny organisms.

Kast, currently at the University of Cambridge, who wrote the study's first iteration, also said, to reach the trophic levels they are gauging in these megatooth sharks, they do not just need to add one trophic level.

This means a single apex predator atop the marine food chain. More so, there is a need to add some to the top of the modern marine food web.

Essentially, megalodon has been approximately 15 meters in length or 50 feet, while modern great white sharks usually top out roughly five meters or 15 feet.

To come up with a conclusion about the ancient marine food web, Kast, together with their colleagues, employed a novel approach to measure the nitrogen isotopes in the teeth of the sharks.

Cannibalism

Ecologists have long known that the more nitrogen-15 has, the higher its level, although scientists have never been able to gauge the small amounts of nitrogen preserved in the enamel layer of the teeth of these extinct predators.

According to Zixuan Rao, a graduate student and co-author of the current study, there's a series of shark teeth from different time periods, and they could trace the animal's trophic level versus their size.

One way of tucking an extra or two trophic levels is cannibalism and numerous lines of evidence point to that in both megatooth sharks and other prehistoric marine predators.

Nitrogen in What Megalodons Ate

In a similar Phys.org report, it was specified that "a few plants, algae, and other species" at the food web's bottom have mastered the skill of turning nitrogen from the water or air into nitrogen in their tissues.

In addition, organisms that consume them then integrate that nitrogen into their bodies, and crucially, they preferentially discharge, sometimes through urine, more of the lighter isotope of nitrogen called N-14, compared to its heavier cousin, N-15. This means that N-15 accumulates relative to N-14 as one climbs the food chain.

Other scientists have used this method on creatures from their recent past, the most recent between 10 and 15 thousand years, although there has not been adequate nitrogen left in older animals to gauge until now.

This is because soft tissue such as skin and muscles is hardly ever preserved. To problematize matters, sharks do not have bones. Rather, their skeletons are made of cartilage.

However, sharks do have a single golden ticket into the fossil record-their; their teeth are more easily preserved than bones since they are encased in enamel, a rock-hard material virtually immune to most decomposing bacteria.

Related information about the megalodon tooth is shown on What's Inside's YouTube video below:

 

RELATED ARTICLE: Evidence of Megatoothed Shark Attack on Whale 15 Million Years Ago Preserved in Ancient Tooth

Check out more news and information on Sharks in Science Times.