A new study published Thursday, November 9 looks at the biomechanics of a prehistoric extinct species of giant otter known as Siamogale melilutra. S. melilutra roamed the China swamp lands six million years ago. The researchers compared it to 13 species of otters living around the world. The ancient predator was larger than the otters seen around the world today. On average, the species weighed 110 pounds. The giant otter was much like wolves seen today, both in its size and rank in the food chain.

The analysis compares prehistoric otter species with living relatives through jaw models

The researchers gathered their data by looking at 13 species of otters currently living across the world. They have successfully created a jaw model for 10 of those species. They then compared the bite strength of living species to a model of a S. melilutra skull. Initially, the researchers hypothesized that the prehistoric otter would have had a weak jaw compared to modern species. However, the researchers found that the jaw of S. melilutra had the biomechanics capable of six times the force they had initially predicted. The research indicates the ancient otter was vastly different from its current living ancestors.

It would have been capable of crushing through hard structures like turtle shells and giant clams. The giant otter’s jaw may have even broken through bird bones. The giant otter would have been a fearsome predator of its time, uncontested by any other predators.

Prehistoric species was much larger than the living species of giant otters found today

Though the giant otter might have been a terrifying predator to come across in its time, living species of otters abandoned their strong jaw biomechanics long ago. The biggest living species of otter today, Pteronura brasiliensis (the giant river otter), is significantly smaller than its prehistoric relative.

P. brasiliensis usually grows to be around 66 pounds and mainly eats freshwater fish and crabs. At half the size of S. melilutra, the giant river otter is still an apex predator, but less threatening than its ancient relative. In fact, if S. melilutra were alive, it would look less like an otter in a sanctuary, and more like the wolves and black bears seen today.

The giant river otter is on its way to joining its distant relative on the list of extinct otters. Find out more about the giant river otter and how to help.