Washington D.C. [USA], Jan. 25 : A team of researchers have discovered prehistoric wolf-sized otter fossils with a large head and a powerful jaw, weighing around 100 pounds, in China's Yunnan province.
The study, published in journal of Systematic Paleontology, claims it to be the largest otter, Siamogale melilutra, almost twice as large as the largest living otters.
It had a large and powerful jaw with enlarged bunodont (rounded cusped) cheek teeth.
These characteristics appear to have been adaptations for eating large shellfish and freshwater mollusks, both were found in abundance at Shuitangba in China.
Otter is a semi aquatic fish-eating mammal of the weasel family, with an elongated body, dense fur and webbed feet.
The discovery of a complete cranium (the skull), mandible, dentition and various skeletal elements provides information about the taxonomy, evolutionary history and functional morphology of this new species.
"While the cranium is incredibly complete, it was flattened during the fossilisation process. The bones were so delicate that we could not physically restore the cranium. Instead, we CT-scanned the specimen and virtually reconstructed it in a computer," said Dr. Denise Su from the Cleveland Museum of Natural History in the U.S.
"From the vegetation and other animal groups found at Shuitangba, we know that it was a swampy, shallow lake with quite dense vegetation," Su added.
It belongs to an ancient lineage of extinct otters, which goes back at least 18 million years, that was previously known only from isolated teeth recovered from Thailand.
"Our phylogenetic analysis suggests that bunodont dentition independently appeared at least three times over the evolutionary history of otters," stated lead study author Dr. Xiaoming Wang from the Natural History Museum of Los Angeles County in the U.S.