Author	Riding, J.B.
Year	1994
Journal	Palynology 18: 11-23
Title	A taxonomic study of the Mesozoic dinoflagellate cysts Phallocysta elongata (Beju 1971) comb. nov., emend. nov. and Wallodinium cylindricum (Habib 1970) Duxbury 1983 emend. nov.

Abstract Riding, J.B., 1994; A taxonomic study of the Mesozoic dinoflagellate cysts Phallocysta elongata (Beju 1971) comb. nov., emend. nov. and Wallodinium cylindricum (Habib 1970) Duxbury 1983 emend. nov.. Palynology 18: 11-23 The Lower-Middle Jurassic dinoflagellate cyst Fromea elongata Beju 1971 is superficially similar to the typically Lower Cretaceous species Wallodinium cylindricum (Habib 1970) Duxbury 1983. Fromea elongata is transferred to Phallocysta D÷rh÷fer & Davies 1980 by virtue of its anterior intercalary periarcheopyle; the specific diagnosis is emended to include this periarcheopyle type. Andreedinium Below 1987 is considered to be a junior synonym of Phallocysta and A. arcticum Below 1987 is transferred to Phallocysta. The uppermost Jurassic-Cretaceous Wallodinium cylindricum is emended largely to note the loose mutual contact of the two cyst walls and the apical peri- and endoarcheopyles, the principal periarcheopyle suture of which appears to be indicative of a gonyaulacacean paratabulation. Wallodinium Loeblich & Loeblich 1968 is therefore emended to include epicavate forms and to note its apparent gonyaulacacean paratabulation. The range of Phallocysta elongata is uppermost Toarcian (Lower Jurassic) to lower Bajocian (Middle Jurassic); all known records are from Europe. Wallodinium cylindricum has been observed from the Kimmeridgian (Upper Jurassic) to the lowermost Cenomanian (Upper Cretaceous) of the North Atlantic, Europe and North Africa; it is most common and persistent in the Lower Cretaceous.