Although Paleocene mammals have been known from western Canada for nearly 70 years, only during the last 15 years have concerted efforts been made to discover, develop, and describe collections documenting their evolution. Whereas much remains to be done, a faunal succession has been reconstructed, based on collections from 41 mammalian local faunas in Alberta and Saskatchewan, ranging from early Puercan to late Tiffanian age (the first 8 to 10 m.y. of the Tertiary).

Latest Cretaceous mammalian local faunas in Saskatchewan show that evolution of progressive “Paleocene aspect” mammals, including condylarths, had begun during the North American Cretaceous as evidenced...