undifferentiated rock units

Paleontology and geology

Throughout the Tertiary, Saskatchewan was above sea level, and deposition was restricted to lakes, rivers, and lowlands. In the Early Tertiary, a warm, humid climate prevailed over the lowlands of Saskatchewan. There were forests and swamps of horsetails, ginkgoes, and cypress, as well as katsura and dawn redwood, plants that now grow only in Southeast Asia. The forests, lakes, and rivers were home to salamanders, crocodiles, turtles, fish, and early mammals, such as marsupials, multituberculates, and primates. By the Middle Tertiary, the climate became cooler and drier. The swamps were replaced by temperate forests, savannas, and eventually grasslands. These environments were home to small mammals like rodents, rabbits, bats, and early horses. Larger mammals include camels, rhinoceros-like brontotheres, pig-like entelodonts, and meat-eating creodonts that resembled large dogs and cats. There were also extremely large tortoises. The fossil record from the Tertiary of Saskatchewan is very rich and is preserved in the sandstones, conglomerates, and shales along the southern edge of the province.