Gonyaulacysta jurassica desmos, a new subspecies of dinoflagellate cyst from the early Oxfordian (Late Jurassic) of Northwestern Europe and East Greenland

In the emendation of Gonyaulacysta jurassica (Deflandre 1938) Norris & Sarjeant 1965 by Sarjeant (1982), a variety of G. jurassica jurassica near the range base was described but not formally named. This variety, herein named G. jurassica desmos subsp. nov., is considered to be of stratigraphical utility because it is confined to the early Oxfordian. Gonyaulacysta jurassica jurassica is emended, and geographic variation in the stratigraphic ranges of the three subspecies of G. jurassica is discussed.