Tyrannosaurus rex and megalodon are recurring sci-fi stars 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 Limits (opens in new tab), is the force generated by the muscles and bones of the upper and lower jaw when an animal bites. Animals with strong bite forces usually have no problem pinning down struggling prey. Some predators are even able to break through prey with particularly strong armor.
Of all the creatures living today, the saltwater crocodile (Crocodylus porosus) has the strongest known bite force, at 16,460 newtons (newtons measure the magnitude of force), a 2012 study in the journal PLOS One (opens in new tab) found it. For comparison, 1 newton is equal to about a quarter pound of force. Anything that enters the jaws of a saltwater crocodile is subjected to extreme force during its dying sighs.
There are two contenders that can challenge – and possibly beat – the crocodile, but their bite forces have not been measured in a live setting because these animals are aquatic predators. If confirmed, the strongest bite force could be that of the orca (Orcinus killer whale), estimated at 84,516 newtons by the Dutch Shark Association (opens in new tab)followed in the distance by the bite force of a great white shark (Carcharodon carcharias), at about 18,000 newtons, according to computer models used in a 2008 study published in the Journal of zoology (opens in new tab).
Among extinct animals, the chomp van T rex might have been king, at a killer 35,000 newtons (opens in new tab) when it stomped the Earth about 68 million to 66 million years ago. The huge shark Megalodon (Otodus megalodon) terrorized the seas from 15 million to 3.6 million years ago with a bite force up to 182,200 Newtons (opens in new tab). However, there are still questions about whether the shark could beat the dinosaur. They’re hard to pit against each other because the jaws of sharks and dinosaurs have different types and numbers of teeth, explained Jack Tseng (opens in new tab)a biologist and assistant professor of integrative biology at the University of California, Berkeley.
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Bite force can be measured directly or estimated indirectly. Living animals can bite a force gauge, which is how scientists measured the saltwater crocodile’s extreme bite. For live animals that scientists haven’t been able to test in this way, such as killer whales and sharks, bite force is based on what is known about their physique, shape and the type of prey they hunt.
Extinct animals are trickier. Only the jawbones are left in a skull. That’s why researchers use computer simulations to recreate jaw muscles that have long since decomposed.
Making a killer bite
What goes into a crushing bite? Multiple characteristics – including head and jaw strength – come into play. Teeth are also a weapon. T rexOnly its head had bone-crushing power, but it also had serrated blade-like teeth. However, there is one factor that dominates all others, if you ask Daniel Huber (opens in new tab)a professor and chair of environmental studies at the University of Tampa in Florida.
“[Body] size is the single most important factor in determining bite force,” Huber told Live Science in an email.
Huber has found that a predator’s size overwhelms everything else, including head width to the armor-like toughness of prey. Crucial are the jaw adductors, which are responsible for closing the jawbones. “The sizes and positions of those adductors can be evolutionarily modified to maximize the amount of muscle force that can be converted into bite force,” he told Live Science in an email.
The iconic T rex supposedly had powerful jaws, according to computer simulations of the dinosaur king (opens in new tab). When the sharpness of its teeth is taken into account, estimates of the dino’s bite force skyrocket, Huber said. But part of that total force comes not only from the bite force, but also from the extra bite pressure exerted by those sharp teeth.
“In general, the sharper the tooth tip, the higher the potential bite force with the same input muscle force, because such force would be concentrated on the tip of a tooth,” Tseng added.
Not all animals with enormous bite force are huge and full of teeth. Some aren’t even predators. The Galapagos large 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 new tab). This bird only weighs about 1 ounce (33 grams), but its bill can crack hard 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 bite force of T rex.
How do people compare? The hardest bite our species can handle is about 1000 Newtons, so we’re not even in the same league.