Two species of a distinctive new genus of dinoflagellate cyst are described from the Early Cretaceous of northern Alberta, Canada. The genotype, Lopsidinium subrisum, comes from the Lower Albian Clearwater Formation, in wells drilled to extract the enormous heavy oil and bitumen resources of the Athabasca and Cold Lake Oil Sands areas, northeastern Alberta. The second species, Lopsidinium paxense, occurs in the Middle Albian, upper Loon River Formation exposed in the banks of the Peace River, northwestern Alberta. Lopsidinium subrisum occurs in assemblages of dinoflagellate cysts associated with brackish water and it is likely that L. paxense is derived from similar environments.