According to research the ancient china had a wolf sized otter which had huge head and dominant jaws. The beast like otter mostly lived in trivial and muddy waters and eats shellfish.
As of the latest record the otter seems to be 6.2 million year old, the scientist says that it would have weighed 50 KG and looked larger than otters that exists today. The remains of the otter were found in 2010 when the team of chines and u.s found a complete skill of otter in china. The skill looked unique and didn’t match any other animal.
A scientist from California named Stuart white used computed tomography scanner and combined the damaged skill with the 3D and gave it a perfect shape.
Again in 2015 the researchers found many more fossils in china which represented the same otter.