Frog Bite

An adult horned frog (Ceratophrys ornata).

A. Kristopher Lappin

Beelzebufo ampinga, or “devil frog,” was a rabbit-sized prehistoric frog that weighed around ten pounds and lived in Madagascar during the late Cretaceous Period, about 70 million years ago. It had a large, wide head with powerful jaws that scientists now think may have allowed it to kill and eat small dinosaurs. 

Kristopher Lappin of California State Polytechnic University led a team of scientists that studied modern-day horned frogs, Ceratophrys cranwelli, to estimate the bite force of the extinct Beelzebufo. The researchers tracked the body size and head size of eight individual Ceratophrys as they developed from post-tadpole froglets to adult frogs. Additionally, they measured the strength of the Ceratophrys’ bite by having the frogs chomp down on a bite bar that was leather-lined to protect their teeth. 

The researchers found that Ceratophrys could bite with up to 30 Newtons (N) of force, much more than that of most other frogs. Ceratophrys, which are known to eat other frogs, small snakes, rodents, and birds, may be such strong biters because their wide heads, rigid skulls, and fused jaws are efficient transmitters of biting force. “That forceful bite allows [Ceratophrys] to clamp onto things that are too big for other frogs to eat, because [other frogs] wouldn’t have the strength to prevent them from escaping,” says Lappin. 

Data from the growing Ceratophrys allowed the team to determine the relationship between the frogs’ bite force and their head and body measurements. They then used the model of this relationship to predict the bite force of Beelzebufo, which had a head width over three times greater than that of Ceratophrys. The team’s calculations suggest that Beelzebufo’s bite force may have been up to 2,200 N—exceeding that of crocodiles and alligators with a similar head width. According to Lappin, “if this frog could do anything close to what living horned frogs can do, then small dinosaurs—maybe something the size of a Cornish game hen or a pigeon—would be fair game.” (Scientific Reports)