Castorocauda

Jurassic beaver-like mammal from China

Castorocauda is an extinct, semi-aquatic, superficially otter-like genus of docodont mammaliaforms with one species, C. lutrasimilis. It is part of the Yanliao Biota, found in the Daohugou Beds of Inner Mongolia, China dating to the Middle to Late Jurassic. It was part of a Middle Jurassic explosive radiation of Mammaliaformes moving into diverse habitats and niches.

From Wikipedia, under CC BY-SA. More on occurri.