Author	Poulsen, N.E. and Riding, J.B.
Year	1992
Journal	Palynology, vol.16: 25-34Palynology, vol.16: 25-34
Title	A revision of the Late Jurassic dinoflagellate cyst Ambonosphaera? staffinensis (Gitmez 1970) comb. nov., and Senoniasphaera jurassica (Gitmez & Sarjeant 1972) Lentin and Williams 1976

Abstract Poulsen, N.E. and Riding, J.B., 1992: A revision of the Late Jurassic dinoflagellate cyst Ambonosphaera? staffinensis (Gitmez 1970) comb. nov., and Senoniasphaera jurassica (Gitmez & Sarjeant 1972) Lentin and Williams 1976. Palynology, vol.16: 25-34 The type material of "Melourogonyaulax" staffinensis Gitmez 1970 and Hexagonifera sp. Gitmez 1970 (later "H. " jurassica Gitmez & Sarjeant 1972) from the earliest Kimmeridgian (Late Jurassic) of Scotland and England has been restudied. The former species is a small (42-51 Ám), camocavate to circumcavate gonyaulacacean cyst with an apical archeopyle and a median parasulcus and is herein questionably attributed to Ambonosphaera Fensome 1979. Sirmiodiniopsisfrisia (Raynaud 1978) Lentin & Williams 1981 is deemed to be a subjective junior synonym of Ambonosphaera ? staffinensis. Senoniasphaera jurassica (Gitmez & Sarjeant l972) Lentin & Williams 1976 is a larger (63-105 Ám), circumcavate species also with a gonyaulacacean paratabulation and an apical archeopyle, but with a markedly offset parasulcal notch. The specific diagnoses of these two Late Jurassic species are emended to include new information on morphology and paratabulation.