Scientists Discover Prehistoric Fossils of New, Huge Otter Species

This week scientists published findings in the Journal of Systematic Palaeontology detailing the discovery of a new prehistoric otter species discovered in China. These were pretty imposing beasts, very different from the otters we feature on the Daily Otter. From the Miocene Epoch, these otters were huge, wolf-sized animals that shared some traits with... badgers, of all things. From Smithsonian:

In 1983 paleontologists described what they thought was a new fossil otter—Siamogale thailandica—from a single molar found in Thailand. But a later study suggested that the animal the tooth belonged to was more like a European badger, and even the discovery of additional teeth did little to resolve where this mammal fit in the carnivoran family tree...

From the fossiliferous wealth held in the 6.2 million-year-old sediment of the Shuitangba coal mine in Yunnan, China, a team of Chinese and American scientists have now described Siamogale melilutra. There are parts of at least three skeletons from this new species of Miocene mammal. But it’s a partly-crushed skull that solves the longstanding riddle once and for all: Siamogale is definitely an otter. Albeit a badger-ish one.

Although time was not kind to the Siamogale skull, the fossil shows significant traits that both solidify its status as an otter and explain why there was some prior confusion over its identity. Part of the rear of the skull called the mastoid bears some telltale otter traits, Natural History Museum of Los Angeles paleontologist Xiaoming Wang and colleagues write, but the first molar—the first piece of Siamogale thailandica found back in the 80s—does look a bit look the same tooth in badgers. The end result is a bulky otter with a few hints of badger-like anatomy about it.

“It has the skull of an otter but shares many dental similarities with badgers,” Wang says, “which is why we called it melilutra”—which is Latin for “badger otter.”

The teeth and overall size of the fossils also give clues to melilutra's eating habits. Again from Smithsonian:

“The fossil otter is larger than all living otters,” Wang says. Yet although many meat-eating mammals evolve larger sizes to tackle bigger prey, Wang says, he expects that the size of Siamogale owes to a different cause. The mammal’s teeth hint that Siamogale was a mollusk eater, Wang points out, similar to modern sea otters. But while sea otters use rocks to crack open their hard-shelled food, it’s unlikely Siamogale did the same.

“Perhaps our fossil otter has not learned to use rocks,” Wang muses, “and instead applied brute strength to crush hard shells?”

Read more at Smithsonian; illustration by Mauricio Antón