A primitive, "obtuse-angled" symmetrodont (Mammalia) from the Upper Cretaceous of Alberta, Canada
An upper molar of an "obtuse-angled" symmetrodont resembling the Jurassic Tinodontidae is described from the Upper Cretaceous Milk River Formation of Alberta, Canada, the first post-Jurassic record of tinodontid-like symmetrodonts. However, in its reduced stylocone and cusp "c," the specimen shows modifications that might have characterized the origin of the aberrant Amphidontidae from more primitive "obtuse-angled" species. The phyletic implications of this new symmetrodont are discussed.