A giant, prehistoric otter's surprisingly powerful bite

Digital, 3-D reconstructions show the skulls — including the jaws — of the roughly 15-pound common otter Lutra lutra (left), and the roughly 110-pound Siamogale melilutra , a giant prehistoric otter with a surprisingly powerful bite (right). Credit: Z. Jack Tseng

Digital, 3-D reconstructions show the skulls — including the jaws — of the roughly 15-pound common otter Lutra lutra (left), and the roughly 110-pound Siamogale melilutra , a giant prehistoric otter with a surprisingly powerful bite (right). Credit: Z. Jack Tseng

BUFFALO, N.Y. — A massive, wolf-sized otter that lived about 6 million years ago may have been a dominant predator in its time, according to a new study analyzing the animal’s jaws.

The research provides insight into the ecological niche that the oversized creature may have filled in the wetlands of southwest China, where it lived. The otter, Siamogale melilutra, weighed about 110 pounds — bigger than any living otter.

“We started our study with the idea that this otter was just a larger version of a sea otter or an African clawless otter in terms of chewing ability, that it would just be able to eat much larger things. That’s not what we found,” says Z. Jack Tseng, PhD, who led the project. Tseng is an assistant professor of pathology and anatomical sciences in the Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, and a research associate with the American Museum of Natural History and the Natural History Museum of Los Angeles County.

When scientists used computers to simulate how biting would strain S. melilutra’s jaws, they concluded that the animal had much firmer jaw bones than expected. This stiffness would have given the otter a surprisingly strong bite — even for its size.

“We don’t know for sure, but we think that this otter was more of a top predator than living species of otters are,” Tseng says. “Our findings imply that Siamogale could crush much harder and larger prey than any living otter can.”

Modern otters have a varied diet, with different species dining on foods that range from plants and rodents to fish, crabs and clams. Based on the new study’s findings, S. melilutra’s jaws would have been strong enough to crush the shells of big mollusks or the bones of birds and small mammals like rodents, though what exactly it ate is unknown.

The study was published on Nov. 9 in Scientific Reports.

The research team included Denise F. Su of the Cleveland Museum of Natural History; Xiaoming Wang of the Natural History Museum of Los Angeles County, American Museum of Natural History, and Chinese Academy of Sciences; Stuart C. White of UCLA; and Xueping Ji of the Yunnan Institute of Cultural Relics and Archaeology in China.