Cimolestes

Cimolestes (from Ancient Greek , 'chalk robber') is a genus of early eutherians with a full complement of teeth adapted for eating insects and other small animals. Paleontologists have disagreed on its relationship to other mammals, in part because quite different animals were assigned to the genus, making Cimolestes a grade taxon of animals with similar features rather than a genus of closely related ones. Fossils have been found in North America, South America, Europe and Africa. Cimolestes first appeared during the Late Cretaceous of North America. According to some paleontologists, Cimolestes died out at the start of the Paleocene, while others report the genus from the early Eocene.

Most species have been described from teeth and isolated fragments. One complete articulated skeleton provisionally assigned to Cimolestes has been found. It shows a small, agile, tree-dwelling predator with long toes for grasping branches and a prehensile tail at least twice the length of its body. It has the largest number of tail vertebrae known in any mammal.