Frogs are generally fairly harmless creatures (poisonous ones aside), but as with many animals their ancestors were far bigger and meaner. The beach ball-sized Beelzebufo, or "devil toad", lived in Madagascar some 68 million years ago, and a new study suggests it may have dined on dinosaurs. By measuring the bite force of its living relatives, researchers were able to scale things up to estimate the jaw strength of the extinct big-mouthed behemoths, and found that dinosaur hatchlings may have been on the menu.

Conducted by scientists from the University of Adelaide, California State Polytechnic University and University College London, the study measured the bite force of South American horned frogs with a custom force transducer. This device is made up of two metal plates covered in leather, and can accurately measure the amount of force applied when the animal bites down on it. According to the researchers, this marks the first time a frog's bite force has been measured.

"Unlike the vast majority of frogs which have weak jaws and typically consume small prey, horned frogs ambush animals as large as themselves – including other frogs, snakes, and rodents," says Marc Jones, an author of the study. "And their powerful jaws play a critical role in grabbing and subduing the prey."

The results of the study found that the small horned frogs, with a head width of about 4.5 cm (1.8 in), pack a bite force of 30 N – the equivalent of 3 kg (6.6 lb). Using that as a baseline for the ratio of bite force to head and body size, the team then estimated the bite force of larger horned frogs. A head width of 10 cm (3.9 in) means these bigger frogs should have a bite force of about 500 N – which rings true for animals of a similar head size.

From there, the team scaled it up further to figure out the bite force of the extinct Beelzebufo. These monsters grew to be up to 41 cm (16 in) long and weighed 4.5 kg (10 lb), and as such, could have packed a bite as strong as a wolf – up to 2,200 N.

"At this bite force, Beelzebufo would have been capable of subduing the small and juvenile dinosaurs that shared its environment," says Jones.

The research was published in the journal Scientific Reports.

Source: University of Adelaide