Dinosaurs from the Paleocene part of the Hell Creek Formation, McCone County, Montana

Dinosaur remains have been recovered from six localities in the uppermost part of the Hell Creek Formation, McCone County, Montana, which on the basis of stratigraphic placement and contained fossil pollen can be shown to be of Paleocene age. This modifies the argument that an extraterrestrial impact event at the Cretaceous/Tertiary (KIT) boundary caused dinosaur extinction (L. W. Alvarez et al., 1984; Alvarez et al., 1980). The occurrence of dinosaurs in sediments younger than the Cretaceousl Tertiary boundary (Rigby, 1985; Rigby and Sloan, 1985; Sloan et al., 1986; and others) supports the argument that dinosaurs survived the impact event. INTRODUCTION