Wolf-Sized Otters Once Prowled Prehistoric Swamps

Art by Mauricio Antón.
Art by Mauricio Antón. / Art by Mauricio Antón.

If the world sometimes seems chaotic today, consider this: Our planet’s swamps were once home to gargantuan otters with mighty, shell-cracking jaws. A report on the newly discovered mega-otters was published in The Journal of Systematic Paleontology. Researchers were digging through an ancient lake bed in China’s Yunnan Province when they found a sizable fossilized skull that resembled that of a modern otter. The skull had been flattened beyond repair but was remarkably complete, and still had its jawbone and teeth. The animal lived about 6.2 million years ago.

Wang et al. 2017. Journal of Systematic Palaeontology

The team carefully brought the bones back to the laboratory, where they used a computed tomography (CT) scanner to capture every detail. They then used those images to virtually reassemble the skull, which made it clear these bones belonged to a previously undiscovered species.

Wang et al. 2017. Journal of Systematic Palaeontology

The shape and proportions of the otter’s sharp teeth and powerful jaws suggest they were used to crush the shells of huge shellfish and other mollusks. Its mouth was quite otter-like, but a bit like a badger's too. This led the team to name the new species Siamogale melilutra—from the Latin melis (otter) and lutra (badger). The researchers estimate the otter would have been about the size of a wolf and would have weighed around 110 pounds.

Co-author Denise Su is Curator and Head of Paleobotany and Paleoecology at the Cleveland Museum of Natural History. She noted in a statement that—like so many scientific discoveries—the skull may raise more questions than it answers: “Why did this species grow so large? How did its size affect its movement on land and in water? And most importantly, what types of advantages did its size give?"