Wolf-sized prehistoric otter: You really oughter check out this critter

New research shows that about 6.2 million years ago, an otter the size of a wolf roamed the rivers and lakes of what is today southwestern China.

Otters, the fuzzy, playful sea mammals of internet fame, may not have been quite as cute 6.2 million years ago. 

Fossils recently unearthed by scientists reveal an ancient wolf-size otter species, known as Siamogale melilutra, that lived in rivers and lakes in a wetland region of southwestern China. It weighed about 110 pounds and measured up to 6.5 feet long, researchers say, dwarfing all of its modern relatives. 

S. melilutra is part of an ancient lineage of extinct otters that were previously identified only from isolated teeth belonging to another species, which were found in Thailand. But scientists were able to recover a mostly complete cranium, mandible, dentition and various skeletal elements, providing researchers with an opportunity to learn more about the taxonomy, evolutionary history, and functional morphology of the newly discovered species.

"Why did this species grow so large?" Denise Su, a curator and head of paleobotany and paleoecology at the Cleveland Museum of Natural History, said in a news release. "How did its size affect its movement on land and in water? And most importantly, what types of advantages did its size give?" 

One defining feature of S. melilutra was its big, strong jaw, thought to have been used to crunch large shellfish or freshwater mollusks, according to the authors of the study, which was published in The Journal of Systematic Palaeontology.

"I think it used its powerful jaws to crush hard clams for food, somewhat like modern sea otters, although the latter use stone tools to smash shells," Xiaoming Wang, the head of vertebrate paleontology at the Natural History Museum of Los Angeles County, told Reuters. "If Siamogale melilutra was not smart enough to figure out tools, perhaps the only option left was to develop more powerful jaws by increasing body size." 

Also notable are its enlarged teeth with rounded cusps, which resemble the teeth found in many otter lineages. Were these rounded-cusped teeth, known as bunodont teeth, inherited by all otters from a common ancestor? Or did they evolve independently in different otter lineages over time as a result of a phenomenon known as "convergent evolution," the evolution of similar adaptations to succeed in similar environments? 

Dr. Wang and Dr. Su believe the S. melilutra's teeth can be attributed to convergent evolution, as they found that bunodont teeth independently appeared at least three times over the evolutionary history of otters. 

Going forward, researchers say they hope studying the S. meliutra will continue to provide them with new insights into the evolutionary history of otters. 

"Siamogale melilutra reminds us, I think, of the diversity of life in the past and how many more questions there are still to answer," Su told Reuters. "Who would have imagined a wolf-size otter?" 

Despite its impressive size, S. melilutra may not be the largest known otter in history: that title, for the moment, could belongs to another ancient otter whose fossils were previously found in Africa, Reuters reports.

This report contains material from Reuters.

You've read  of  free articles. Subscribe to continue.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.

QR Code to Wolf-sized prehistoric otter: You really oughter check out this critter
Read this article in
QR Code to Subscription page
Start your subscription today