Extinct Wolf-Sized Otter Had Powerful Bite That Likely Made It Top Predator. An adult North American river otter can weigh between 5.0 and 14 kg (11.0 and 30.9 lb). Brett Tingley January 24, 2017. The fossils belong to a new species of ancient otter… Wolf-Sized Otter Discovered in China. A large extinct otter, Siamogale melilutra, has been found in the Miocene Shuitangba site in northeastern Yunnan Province in China. The river otter is protected and insulated by a thick, water-repellent coat of fur. The research provides insight into the ecological niche that the oversized creature may have filled in the wetlands of southwest China, where it lived. 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 species is called Siamogale melilutra, was the size of a wolf and weighed about 110 pounds (50kg). ... but the largest otters today are the giant otter and the sea otter, by size and weight respectively. 2 An artist's impression of the ancient killer otter Credit: PA:Press Association A newly published study reveals that a massive, wolf-sized otter that lived about 6 million years ago may have been a dominant predator in its time. Otter Size Lenght Lenght 1X Over 38" Over 96.5 cm LG 34" - 38" 86 - 96.5 cm LM 32" - 34" 81 - 86 cm MS 30" - 32" 76 - 81 cm XS Under 30" Under 76 cm In order to achieve the best results we recommend that you mark the pelt sizes on each board. Researchers have uncovered the remains of a giant otter in China that when alive would have been comparable to the size of a wolf. Otters had wolf-sized ancestors with powerful teeth, scientists reveal. The North American river otter (Lontra canadensis), also known as the northern river otter or common otter, is a semiaquatic mammal endemic to the North American continent found in and along its waterways and coasts. Scientists have unearthed fossils of an otter as big as a wolf that frolicked in rivers and lakes in a lush, warm and humid wetlands region in south-western China about 6.2m years ago. With "wolf-like" proportions, and weighing roughly 100 Ibs, the creature -- whose skull was excavated in Yunnan province -- would have been twice the size of today's otters. Scientists say the Siamogale melilutra ancestor species could crush …