Four new species and one new variety of dinoflagellate cysts and one new acritarch species are described from the Lower Cretaceous Athabasca Oil Sands of northern Alberta, Canada. The new taxa are Batioladinium? vestigium var. vestigium, Batioladinium? vestigium var. granulatum, Craspedodinium robustum, Nyktericysta inflata, Oligosphaeridium tuberculatum and Fromea? plicata. They characterise brackish to stressed marine environments in the McMurray, Clearwater and Grand Rapids formations.