Scientists Discover Prehistoric Giant Otter Species In China 
 
 Enlarge this image toggle caption Mauricio Antón/Journla of Systematic Palaeontology Mauricio Antón/Journla of Systematic Palaeontology 
 
 Six million years ago, giant otters weighing more than 100 pounds lived among birds and water lilies in the wooded wetlands of China's Yunnan province. 
 
 That's according to new research from a team of scientists who discovered a well-preserved cranium of the newly-discovered species in an open lignite mine in 2010. They recently published their findings in the Journal of Systematic Palaeontology. 
 
 The researchers concluded that this wolf-sized prehistoric creature is "two to three times larger than any modern otter species," Denise Su, the head of paleobotany and paleoecology at the Cleveland Museum of Natural History, tells The Two-Way. 
 
 The fossilized cranium was nearly complete, but flattened to about an inch and a half thick. "The bones are pretty fragile, so we couldn't really reconstruct it physically," Su said. "So what we did is we took CT scans of the cranium, and then we digitally reconstructed it." 
 
 The cranium was particularly interesting because it revealed that the animal's teeth had "some badger features," Su explains. The species name Siamogale melilutra, is a nod to that – in Latin, meles means badger and lutra means otter. 
 
 toggle caption Xiaoming Wang 
 
 And the completeness of the cranium provided the researchers with important information about how otters evolved, Su said. It shed light on a dental mystery in particular. 
 
 The giant otters possessed large bunodont, or round-cusped, teeth. Scientists have wondered whether different species of otters inherited these teeth from a common ancestor, or evolved them separately because they were eating similar things – a process known as convergent evolution. 
 
 But by comparing this specimen to modern and other fossil otters, Su says they found "these bunodont teeth actually arose at least four different times within the greater otter lineage." That finding suggests they emerged because of convergent evolution, rather than inheritance from a common ancestor. 
 
 The scientists initially found other bones from the species in 2009, including an upper arm bone. Su remembers looking at that bone and thinking, "This looks like an otter but it's huge. ... Is this really an otter?" 
 
 There are big questions about why the animal was so large and how it moved on land and in water. 
 
 "A lot of times in modern carnivores, the large size is partly due to subduing prey, so their prey is bigger and the carnivores also get bigger," Su explains. But the scientists think that this animal likely ate small creatures such as mollusks – so, "why the big size?" 

 Dr. Xiaoming Wang, Curator and Head of Vertebrate Palaeontology at the Natural History Museum of Los Angeles County and Dr. Denise Su, Curator & Head of Paleobotany and Paleoecology at the Cleveland Museum of Natural History have published a paper with colleagues in the Journal of Systematic Paleontology on the discovery of one of the largest otter species ever found. This discovery was made in the Yunnan Province, Southwestern China by an international team of scientists from the United States, France, and China. It represents groundbreaking research into the evolution of a little-known fossil genus of the otter family. 
 
 This newly discovered species of otter, Siamogale melilutra, belongs to an ancient lineage of extinct otters that was previously known only from isolated teeth recovered from Thailand. The discovery of a complete cranium, mandible, dentition and various skeletal elements at Shuitangba 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 fossilization 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. Su. The CT restoration revealed a combination of otter-like and badger-like cranial and dental feature, hence its species name, "melilutra," which refers to meles, Latin for badger, and lutra, Latin for otter. 
 
 Siamogale melilutra was about the size of a wolf and weighed approximately 110 lbs., 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 of which were found in abundance at Shuitangba. "From the vegetation and other animal groups found at Shuitangba, we know that it was a swampy, shallow lake with quite dense vegetation," said Dr. Su. 
 
 "Multiple otter lineages have low-crowned bunodont teeth, leading us to ask the question if this was inherited from a common ancestor or if this was convergent evolution based on common dietary behaviors across different species," said Dr. Wang, lead author of the paper. "Our phylogenetic analysis suggests that bunodont dentition independently appeared at least three times over the evolutionary history of otters." 
 
 The completeness of the specimens from Shuitangba allows the scientists to better understand the evolutionary history of otters and specifically this enigmatic genus from the Miocene, of which there had been little information. The findings from Shuitangba reveal that Siamogale belongs to one of the oldest and most primitive lineages of the otter family, which goes back at least 18 million years in the form of Paralutra from Europe. 
 
 The scientists are working to understand other aspects of the life of Siamogale melilutra. 
 
 "The discovery of the otter helps solve some questions about otter relationships, but has opened the door to new questions," said Dr. Wang. For instance, why was it so large, how did it crack open mollusks and shellfish for food, and how did it move in the water and on land? 
 
 "Continued studies by our group will address these fundamental questions and give us a more complete picture of its paleobiology," said Dr. Su. 

 A fearsome, wolf-size otter with a large head and a powerful jaw once swam around the shallow, swampy waters of ancient China, likely hunting for clams and other shellfish, a new study finds. 
 
 The 6.2-million-year-old beast is among the largest otter species on record, the researchers in the new study said. At 110 lbs. (50 kilograms), the animal would have been about twice the size of the modern-day South American giant river otter (Pteronura brasiliensis) and about four times the size of the Eurasian otter (Lutra lutra), the researchers said. 
 
 "This extinct otter is larger than all living otters," said study lead researcher Xiaoming Wang, a curator of vertebrate paleontology at the Natural History Museum of Los Angeles County in California. [See images of the fearsome wolf-size otter] 
 
 Researchers discovered the otter's remains in 2010, after a Chinese and U.S. field team found a nearly complete skull in Shuitangba quarry, located in southwestern China. 
 
 "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," Wang told Live Science. 
 
 The wolf-size otter lived in a shallow swamp surrounded by thick vegetation. Credit: Mauricio Antón 
 
 However, piecing the skull together was a challenging feat. "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," Wang said. 
 
 By using a computed tomography (CT) scanner, study co-author Stuart White, a professor emeritus of maxillofacial radiology at the University of California, Los Angeles, was able to digitally restore the skull's 3D shape. Wang compared the reconstruction to "playing a three-dimensional jigsaw puzzle, only to be done by computer mouse rather than by hands." 
 
 Because the skull was flattened like a pancake, researchers did a computed tomography (CT) scan of the fossil. Each color in this digital scan represents an individual fragment. Credit: Stuart C. White 
 
 Later, in 2015, the researchers found more fossils in the quarry belonging to the same species; these finds included lower jaws, teeth and several limb bones, Wang said. 
 
 A cranial analysis showed that while the skull of the newly discovered creature is like that of an otter, it has badger-like teeth, Wang said. This inspired the researchers to name the newfound species Siamogale melilutra, because "meles" is Latin for badger and "lutra" is Latin for otter, Wang said. 
 
 S. melilutra belongs to an "obscure group of extinct otter in East Asia [that] diverged early from the main otter lineage and formed a distinct group of its own," Wang said. Until now, researchers only knew about this lineage from fossilized teeth found in Thailand, the scientists said. 
 
 The skull is like that of an otter, but the teeth are like those of a badger. Credit: Xiaoming Wang 
 
 Moreover, the new findings suggest that S. melilutra belongs to one of the oldest and most primitive otter lineages, one that goes back at least 18 million years, to the European, badger-like animal Paralutra, the researchers said. 
 
 It's unclear why S. melilutra was so big, the researchers said. Usually, when carnivores evolve to be large, it's so that they have the strength to subdue prey, Wang said. 
 
 "But in our fossil otter, it is more likely a mollusk eater, and its powerful skull and jaws may be designed to crack tough shells of clams," he said. 
 
 Wang noted that modern sea otters also crack mollusks. But in addition to using their powerful teeth, these modern species also use tools — that is, rocks — to smash open the shells. [10 Animals That Use Tools] 
 
 "Perhaps our fossil otter had not learned to use rocks, and instead [would] apply brute strength to crush hard shells," Wang said. 
 
 This question is just one of many that researchers have about S. melilutra, said study co-researcher Denise Su, a curator at the Cleveland Museum of Natural History. 
 
 "We are working to answer questions regarding its paleobiology, like, 'How did it swim? How did it move on the ground? Why is it so large?'" 
 
 The study was published online today (Jan. 23) in the Journal of Systematic Paleontology. 
 
 Original article on Live Science.
– Picture an otter, then envision it ballooning to twice—or triple, or quadruple—its size until it's a 110-pound creature: It's not a journey into the imagination, but to yesteryear. An international team of scientists has announced news of the largest otter ever found, one that lived some 6.2 million years ago and has been given the name Siamogale melilutra, the latter word a mash-up of the Latin words for "badger" and "otter." The discovery was made after studying an "incredibly complete," though completely flattened fossilized cranium found in a mine in China's Yunnan Province, researcher Denise Su explains in a press release. She says the bones were in such fragile condition that a physical reconstruction wasn't possible—so the team relied on CT scans and virtually reconstructed it instead. The end result revealed a head with badger-like dental characteristics, says Su, hence the animal's name. The researchers believe the creature was a mollusk-eater, which raises a, well, big question. "A lot of times in modern carnivores, the large size is partly due to subduing prey, so their prey is bigger and the carnivores also get bigger," Su tells NPR. An otter wouldn't need to be wolf-sized—as Siamogale melilutra was, clocking in at about twice the size of the South American giant river otter—to eat mollusks. Or would it? Lead researcher Xiaoming Wang speculates that perhaps these ancient otters hadn't learned how to use rocks, as modern otters do, to open mollusks. It's possible they needed to "apply brute strength" from their large jaws "to crush hard shells," he tells Live Science.