Fossilized shark teeth are some of the most abundant remnants of prehistoric oceans, providing scientists with crucial insights into the lives of long-extinct species. While fossils have a way of captivating the imagination — sparking wonder in people from all walks of life no matter the species uncovered — there’s something about a Megalodon find that grips our attention like no other.
Scientifically known as Otodus megalodon, the Neogene-era shark is estimated to have reached lengths of 50 to 65 feet (15 to 20 meters) and once belonged to a lineage of sharks that evolved during the Cenozoic era, becoming increasingly specialized for preying on and scavenging marine mammals. Its reputation as a ruthless apex predator is well-established; fossilized whale bones bear deep Megalodon tooth marks, providing clear evidence of their feeding habits, reinforcing the idea that Megalodon sat at the top of the marine food chain. Chemical analyses of Megalodon teeth, examining nitrogen and zinc isotopes, further confirm its status as an apex predator.
Much of what we know about this apex predator comes from its teeth — some measuring over seven inches long! Recently, a handful have been found bearing serrated gouges… marks that could only have been made by the teeth of another Megalodon, suggesting interactions that go beyond simple feeding. See, most shark bite fossils document predation attempts or scavenging, where teeth left their marks on bones and other hard tissues. Finding Megalodon teeth with distinct serration gouges from another Megalodon’s bite is incredibly rare. The marks match a trace fossil type known as Knethichnus parallelum, a pattern of parallel grooves made when serrated shark teeth scraped across a surface.
These scars on Megalodon teeth suggest that in certain instances, these massive sharks were biting one another. The big question is: why?
One possibility is that these bites were the result of feeding accidents. Megalodon likely fed with immense force, using its powerful jaws to shear through its prey’s thick bones and flesh. If multiple Megalodons were scavenging the same carcass, it’s possible they occasionally bit into each other’s teeth by mistake. This type of accidental contact is seen in modern sharks, particularly around whale carcasses where multiple individuals gather to feed. The same scenario could have played out in the prehistoric oceans, with large Megalodons competing for the same food sources.
Another hypothesis the scientists of this documented find, Dr. Stephen James Godfrey and Dr. Victor Perez, is that some of these bites may have been the result of intraspecies aggression. Many modern sharks exhibit aggressive behaviors toward one another, often in the form of dominance displays or territorial disputes. Male sharks are also known to bite females during mating, leaving distinctive scars. While it’s difficult to prove that Megalodon engaged in similar behaviors, the presence of bite marks on their teeth raises the possibility that these massive sharks occasionally clashed — either in competition or as part of reproductive interactions.
The fossil record contains only a few examples of these self-bitten Megalodon teeth, emphasizing how rare this phenomenon is. Among the notable specimens, a Megalodon tooth from North Carolina’s Nutrien Mine shows deep serration marks running diagonally across the root, evidence of a strong bite from another Megalodon. Other examples, collected from riverbeds and fossil sites in South Carolina and Maryland, display similar markings, though the exact reasons behind these bites remain a mystery. Because the exact positioning of these teeth in Megalodon’s mouth is unknown, estimating the size of both the bitten and biting individuals is difficult. However, body length approximations based on tooth measurements suggest that these sharks ranged from about 40 to 65 feet (12 to 19.5 meters) in length.
Whether these marks resulted from feeding frenzies, accidental collisions, or more complex social behaviors, they provide an intriguing new perspective on the interactions of these ancient giants. They also remind us that even the most fearsome predators may not always have the upper hand in their own world.
