by Tyrannosaurus rex and megalodons are recurring stars of science fiction for a reason: their bites were ferocious. But which extinct and living creatures actually exert the strongest bite force?
Bite force, according to a study published in Borders (opens in a new tab), is the force that the muscles and bones of the upper and lower jaw generate when an animal bites. Animals with strong bite forces usually have no problems clamping down on struggling prey. Some predators are even able to break through prey with particularly tough armor.
Of all the creatures alive today, the saltwater crocodile (Crocodylus porosus) has the strongest known bite force, at 16,460 newtons (the newton measures the magnitude of force), a 2012 study in the journal PLOS One (opens in a new tab) found. By comparison, 1 newton equals about a quarter of a pound of force. Whatever ends up in the jaws of a saltwater crocodile is subjected to extreme force during its dying gasp.
There are two contenders that can challenge – and possibly beat – the hook, but their bite forces have not been measured in a live setting because these animals are aquatic predators. If confirmed, the strongest bite force may be that of killer whale (Orcinus orca), estimated at 84,516 newtons of Dutch Shark Society (opens in a new tab)distantly followed by the bite force of a great white shark (Carcharodon carcharias), of around 18,000 newtons, according to computer models used in a 2008 study published in Journal of Zoology (opens in a new tab).
Among extinct animals, chomp of T. rex may have been king, on a killer of 35,000 newtons (opens in a new tab) when it trampled the Earth from about 68 million to 66 million years ago. The huge shark Megalodon (Otodus megalodon) terrorized the oceans from 15 million to 3.6 million years ago with a bite force of up to 182,200 newtons (opens in a new tab). However, the question remains whether the shark can beat the dinosaur. They are difficult to put against each other because shark and dinosaur jaws have different types and numbers of teeth, he explained Jack Tseng (opens in a new tab)a biologist and assistant professor of integrative biology at the University of California, Berkeley.
Related: What is the toothiest animal on earth?
Bite force can be measured directly or estimated indirectly. Live animals can bite down on a force meter, which is how the researchers measured the saltwater crocodile’s extreme bite. For living animals that scientists have not been able to test in this way, such as killer whales and sharks, bite force is based on what is known about their body structure, shape and the type of prey they are hunting.
Extinct animals are more difficult. Only the jawbones remain in a skull, which is why scientists use computer simulations to recreate jaw muscles that have long since broken down.
Making a killer bite
What goes into a crushing bite? Several traits – including head and jaw strength – play roles. The teeth are also a weapon. T. rexthe head alone had bone-crushing power, but it also had jagged knife-like teeth. However, there is one factor that dominates all others, you ask Daniel Huber (opens in a new tab)professor and head of environmental studies at the University of Tampa in Florida.
“[Body] size is the single most important factor in determining bite force,” Huber told LiveScience in an email.
Huber has found that the size of a predator overwhelms everything else, including head width to the armor-like toughness of its prey. The jaw adductor muscles, which are responsible for closing the jawbones, are crucial. “The sizes and positions of these adductors may have changed evolutionarily to maximize the amount of muscle force that can be transferred into bite force,” he told LiveScience in an email.
The iconic T. rex presumably had powerful jaws, according to computer simulations of the dinosaur king (opens in a new tab). When you factor in the sharpness of the teeth, estimates of the dino’s bite force skyrocket, Huber said. But part of the total force comes from not only biting force, but also the additional biting pressure exerted by the sharp teeth.
“In general, the sharper the tooth tip, the higher the potential bite force given the same input muscle force, because any such force will be concentrated at the tip of a tooth,” Tseng added.
Not all animals with an enormous bite force are huge and full of teeth. Some are not even predators. Galapagos great ground finch (Geospiza magnirostris) has the most intense bite force for its size, according to a 2019 study published in the journal Proceedings of the Royal Society B (opens in a new tab). This bird weighs only about 1 ounce (33 grams), but its beak can crack tough nuts and seeds with a force of 70 newtons, meaning it has the most powerful bite force for its body size, according to the study. That gives the finch 320 times the biting force T. rex.
How do people compare? The hardest bite our species can manage is around 1000 newtons, so we’re not even in the same league.
