Giant Prehistoric Otter – Siamogale melilutra

A team of international researchers, including scientists from Cleveland Museum of Natural History and the Natural History Museum of Los Angeles County, have described the fossilised skull, teeth and limbs of a giant prehistoric otter that roamed south-western China some 6.25 million years ago.  The fossil material, which includes a crushed, but quite well preserved skull, represents a new species in the sub-family Lutrinae (otters).  The prehistoric otter has been name Siamogale melilutra and it probably weighed six times heavier than the European otter.

A Giant Prehistoric Otter

An Illustration of the Giant Otter from the Late Miocene Epoch

Siamogale illustration.

Yunnan Province (south-western China), in the Late Miocene was home to a giant otter (S. melilutra).

Picture credit: Mauricio Antón

Siamogale melilutra

Palaeontologists have suggested that this otter probably weighed in excess of fifty kilogrammes and it specialised on feeding on clams and freshwater mussels.  It lived during the Late Miocene Epoch, a time when south-western China was covered in a dense, lush forest.  Siamogale melilutra shared its home with tapirs, several species of ancient elephants and crocodiles.  It is related to another ancient otter species from Thailand.

Convergent Evolution

S. melilutra had a large, powerful jaw with enlarged, bunodont (rounded-cusped) teeth typical of many otter lineages.  The discovery of these fossils, far more complete than the fossils of other ancient otters, poses the question of whether these bunodont teeth were inherited by all otters from a common ancestor, or evolved independently in different otter genera over time because of the evolution of similar adaptations to thrive in similar environments, (convergent evolution).

Skull Size Comparison Between S. melilutra and the Living Giant South American Otter and the European Otter found in the British Isles

Otter skull comparisons.

Siamogale skull size comparison with South American giant river otter (middle) and European otter (right).

Picture credit: The Journal of Systematic Palaeontology

Everything Dinosaur acknowledges the help of the Cleveland Museum of Natural History in the compilation of this article.

The scientific paper: “A New Otter of Giant Size Siamogale melilutra sp. nov. (Lutrinae: Mustelidae: Carnivora), from the latest Miocene Shiutangba site in north-eastern Yunnan, south-western China, and a total-evidence of phylogeny of Lutrines.” published in “The Journal of Systematic Palaeontology”.

Visit the award-winning Everything Dinosaur website: Everything Dinosaur.