Researchers Discover Crocodile Bite Force Correlates with Size, with Saltwater Crocodiles Having the Strongest Bite.
In the book “Bite: An Incisive History of Teeth, from Hagfish to Humans,” author Bill Schutt explores the animals with the strongest bite forces in the world. As a zoologist specializing in vertebrates, Schutt investigates the impressive bite force of living crocodile species as well as their fearsome ancestors. He collaborated with Gregory Erickson, a professor of anatomy and vertebrate paleontology at the University of Florida, to measure the bite force of specimens, according to Live Science.
Saltwater crocodiles possess an enormous bite force. (Photo: BBC).
After being securely restrained, a gentle tap on the snout usually prompts the test subject to open its mouth. The researcher then places a bite bar at the back teeth, as physical laws indicate that measurements taken near the jaw joint will yield the highest bite force. Here, the crocodile’s reflex is to crush the bite bar with full force.
Although Erickson’s initial experiments focused on short-snouted crocodiles, he and his team ultimately collected bite force data from all 23 crocodile species, including African crocodiles, short-snouted crocodiles, caimans (found in Central and South America), and Indian crocodiles. The largest specimen they measured was a saltwater crocodile (Crocodylus porosus) measuring 5.2 meters long, along with the Nile crocodile (Crocodylus niloticus), both of which are responsible for numerous human attacks.
The research team was interested in determining how bite force varies among species. Prior to the study, some hypotheses suggested that bite force in crocodiles would vary according to factors such as tooth shape, jaw length, or width, which are commonly used characteristics for species identification.
However, what surprised Erickson and his colleagues was that bite force depended solely on body size. In other words, if African crocodiles, short-snouted crocodiles, and caimans all weighed 45 kg, their bite forces would be the same. All smaller species would exhibit lower bite forces. The 5.2-meter-long saltwater crocodile generates a bite force of 1,680 kg, but when reaching a record size of 7 meters, Erickson found that a bite force of 3,500 kg is not out of the question.
Nevertheless, there are two exceptions to the bite force/size correlation, which are the two species of Indian crocodiles (Gavialis gangeticus and Tomistoma schlegelii), possessing exceptionally long snouts that seem oddly attached to bodies measuring 3.7 – 4.7 meters and weighing around 900 kg. Their extremely long snouts are equipped with 110 sharp teeth that interlock. This entire structure is perfectly adapted for snapping through the water with minimal resistance. However, their bite force is significantly lower than expected for their size. Erickson posits that the Indian crocodiles’ unique fish-catching strategy is the reason, leading to a trade-off where they sacrifice a strong bite force for the ability to snap at fish quickly.
Both living species of Indian crocodiles are critically endangered. In the riverine habitats of northern the Indian subcontinent, their populations are dwindling to just a few hundred individuals.
