Giant Otters Used to Be Fearsome Hunters in Ancient China

Six million years ago, massive otters roamed the Earth armed with powerful jaws and very big skulls. This image is a far cry from the adorable creatures that otters are known for being now, but new research revealed they used to be a lot more fearsome than the world gives them credit for.

According to a report from Live Science, scientists unearthed a 6.2 million year old fossil that turned out to be the largest otter ever on record. This impressive animal was revealed to be two times larger than today's South American giant sea otter and four times larger than the Eurasian otter.

The fossil was discovered back in 2010. It was nearly a complete skull when Chinese and American scientists found it in the Shuitangba quarry in southwestern China.

Lead researcher of the study Xiaoming Wang explained that this prehistoric otter - now extinct - is bigger than all of the other otter species that survived. Wang is also a curator of vertebrate paleontology at the Natural History Museum of Los Angeles County in California.

"The skull was unlike [that of] any other animals found so far, and that's when we realized that this is something unique and important," he added, then shared the challenges that came with the millions-year-old remains. "Because the skull was preserved in soft brown coal, it has been badly crushed into a pancake-like shape during the compaction of soft sediments."

In 2015, additional bones of the same species were found in the quarry. These included lower jaws, limbs and teeth.

Eventually, the team was able to piece together the arts and create a more complete picture of what they call the "obscure" species. Named the Siamogale melilutra, the extinct otter was part of one of the most primitive lineages that can be traced to at least 18 million years ago.

Interestingly enough, the size of this animal is somewhat surprising as many carnivores that evolve to be this large did so to subdue prey. Instead, the S. melilutra ate mollusks, although their powerful jaws were probably useful in cracking clam shells. Modern otters use tools like sharp rocks, but their ancient cousins may have been able to feed without extra help.

The new study was published online in the Journal of Systemic Paleontology.