November 22, 2024

Great Whites May Have Contributed to Extinction of Megalodon Sharks

Scientist evaluated zinc isotopes in teeth and found that excellent white sharks make have actually added to the termination of megalodon.
Researchers examined the diet plan of megalodon, the largest shark to have ever lived, using zinc isotopes.
In a new research study, researchers compared how high up the food cycle megalodon and terrific white sharks feed, by examining the zinc stable isotope ratios in their teeth. They discovered that there was likely overlap in the victim of both species, and for that reason, dietary competition with great white sharks might have added to the termination of megalodon.
Megatooth sharks like, Otodus megalodon, more commonly referred to as megalodon, lived between 23 and 3.6 million years ago in oceans around the world and perhaps reached as large as 20 meters (66 feet) in length. For comparison, the biggest great white sharks today reach a total length of only 6 meters (20 feet). Many factors have been discussed to describe the gigantism and extinction of megalodon, with its diet plan and dietary competition typically being considered essential elements.

In this research study, researchers examined zinc steady isotope ratios in modern and fossil shark teeth from around the world, including teeth of megalodon and modern and fossil excellent white sharks. This brand-new method enables researchers to examine an animals trophic level, which shows how far up the food cycle an animal feeds. Zinc steady isotope analysis of tooth enameloid, the extremely mineralized part of teeth, is comparable to much more recognized nitrogen isotope analysis of tooth collagen, the natural tissue in tooth dentine, which is used to examine the degree of animal matter usage.
“on the timescales we investigate, collagen is not protected, and standard nitrogen isotope analysis is therefore not possible,” describes lead author Jeremy McCormack, a researcher at the Max Planck Institute for Evolutionary Anthropology and the Goethe-University Frankfurt. “Here, we show, for the very first time, that diet-related zinc isotope signatures are maintained in the highly mineralized enameloid crown of fossil shark teeth,” includes Thomas Tütken, professor at the Johannes Gutenberg Universitys Institute of Geosciences.
Tooth size contrast in between extinct Early Pliocene Otodus megalodon tooth and a modern terrific white shark. Credit: © MPI for Evolutionary Anthropology
Contrast of zinc isotope signals in fossil and modern-day sharks
Using this brand-new technique, the team compared the tooth zinc isotope signature of numerous extinct Early Miocene (20.4 to 16.0 million years ago) and Early Pliocene (5.3 to 3.6 million years ago) species with those of modern-day sharks. “We noticed a coherence of zinc isotope signals in fossil and contemporary analog taxa, which boosts our self-confidence in the technique and suggests that there may be very little distinctions in zinc isotope values at the base of marine food webs, a confounding factor for nitrogen isotope research studies,” describes Sora Kim, a teacher from the University of California Merced.
Subsequently, the researchers examined the zinc isotope ratios in megalodon teeth from the Early Pliocene and those in earlier megatooth sharks, Otodus chubutensis, from the Early Miocene as well as contemporary and synchronous fantastic white sharks to investigate the effect these iconic types had on previous communities and each other. “Our results reveal, that both megalodon and its ancestor were undoubtedly peak predators, feeding high up their respective food cycle,” states Michael Griffiths, professor at the William Paterson University. “But what was really impressive is that zinc isotope worths from Early Pliocene shark teeth from North Carolina, suggest largely overlapping trophic levels of early excellent white sharks with the much bigger megalodon.”
Lead author Jeremy McCormack isolating zinc from shark tooth samples by column chromatography in metal-free tidy lab. Credit: © MPI for Evolutionary Anthropology
Dietary competition of megalodon with excellent white sharks
” These results most likely imply at least some overlap in victim hunted by both shark types,” keeps in mind Kenshu Shimada, professor at DePaul University, Chicago. “While extra research is needed, our results appear to support the possibility for dietary competitors of megalodon with Early Pliocene fantastic white sharks.”
New isotope approaches such as zinc offer an unique window into the past. “Our research shows the expediency of using zinc isotopes to examine the diet and trophic ecology of extinct animals over millions of years, an approach that can also be used to other groups of fossil animals including our own ancestors,” concludes McCormack.
Recommendation: “Trophic position of Otodus megalodon and great white sharks through time revealed by zinc isotopes” 31 May 2022, Nature Communications.DOI: 10.1038/ s41467-022-30528-9.

Megatooth sharks like, Otodus megalodon, more typically known as megalodon, lived between 23 and 3.6 million years earlier in oceans around the globe and potentially reached as big as 20 meters (66 feet) in length. For comparison, the largest terrific white sharks today reach an overall length of only six meters (20 feet). In this research study, researchers evaluated zinc stable isotope ratios in modern-day and fossil shark teeth from around the world, including teeth of megalodon and contemporary and fossil excellent white sharks. Consequently, the researchers analyzed the zinc isotope ratios in megalodon teeth from the Early Pliocene and those in earlier megatooth sharks, Otodus chubutensis, from the Early Miocene as well as contemporary and contemporaneous great white sharks to investigate the impact these iconic species had on previous ecosystems and each other. “But what was truly impressive is that zinc isotope worths from Early Pliocene shark teeth from North Carolina, suggest mostly overlapping trophic levels of early great white sharks with the much larger megalodon.”