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Ectosphaeridium
From Williams et al., 2017:
[Ectosphaeridium, Zevenboom and Santarelli in Zevenboom, 1995, p.150.
Name not validly published: considered a manuscript name by the authors.
Type species: Membranilarnacia? picena, Biffi and Manum, 1988 (pl.7, figs.1,5,9,12)]
Manuscript type: Ectosphaeridium picenum, (Biffi and Manum, 1988) Zevenboom and Santarelli, comb. Nov.; Biffi and Manum, 1988 , plate 7, figs. 1,5,9,12.
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Original description: [Zevenboom, 1995]:
Diagnosis:
Subspherical gonyaulacoid skolochorate holocovate cysts. The periphragm gives rise to penitabular process-complexes overlain distally by a thin discontinuously developed ectophragm. The ectophragm covers the process-complexes completely and reflects paraplates allowing the recognition of a gonyaulacoid arrangement (Plate II, 1-4). The archeopyle is apical (4A). The operculum is compound (4a) and free.
Description:
Gonyaulacoid subspherical skolochorate holocavate dinoflagellate cysts. The endophragm is smooth and thin, closely appressed to the periphragm. The periphragm gives rise to penitabular process-complexes overlain distally by a thin discontinuously developed ectophragm. The ectophragm covers the process-complexes completely and reflects paraplates allowing the recognition of a sexiform gonyaulacoid organisation 4', 6", 0=6c, 0-5s, 5"', 1p and 1"". The paracingular processes, if present, and notably the sulcal processes are also covered by the ectophragm, which hampers the recognition of the exact number of processes in these regions. Between the reflected paraplates thin strands of ectophragm connects the process-complexes distally. The archeopyle is apical (4A). The operculum is compound (4A) and free.
Discussion:
Ectosphaeridiumis morphological similar to Membranilarnacia Eisenack, 1963 emend. Williams and Downi, 1966, Glaphyrocysta Stover and Evitt, 1978 and Eatonicysta Stover and Evitt, 1978, in overall shape and archaeopyle formation. Ectosphaeridium differs from Membranilarnacia in having intratabular process-complexes rather than randomly distributed processes. Glaphyrocysta Stover and Evitt, 1978 differs from Ectosphaeridium in lacking dorsal and ventral processes and an ectophragm. Ectosphaeridium differs from Eatonicysta Stover and Evitt, 1978 in having groups of processes rather than intratabular ones and the possession of an ectophragm.
[Ectosphaeridium, Zevenboom and Santarelli in Zevenboom, 1995, p.150.
Name not validly published: considered a manuscript name by the authors.
Type species: Membranilarnacia? picena, Biffi and Manum, 1988 (pl.7, figs.1,5,9,12)]
Manuscript type: Ectosphaeridium picenum, (Biffi and Manum, 1988) Zevenboom and Santarelli, comb. Nov.; Biffi and Manum, 1988 , plate 7, figs. 1,5,9,12.
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Original description: [Zevenboom, 1995]:
Diagnosis:
Subspherical gonyaulacoid skolochorate holocovate cysts. The periphragm gives rise to penitabular process-complexes overlain distally by a thin discontinuously developed ectophragm. The ectophragm covers the process-complexes completely and reflects paraplates allowing the recognition of a gonyaulacoid arrangement (Plate II, 1-4). The archeopyle is apical (4A). The operculum is compound (4a) and free.
Description:
Gonyaulacoid subspherical skolochorate holocavate dinoflagellate cysts. The endophragm is smooth and thin, closely appressed to the periphragm. The periphragm gives rise to penitabular process-complexes overlain distally by a thin discontinuously developed ectophragm. The ectophragm covers the process-complexes completely and reflects paraplates allowing the recognition of a sexiform gonyaulacoid organisation 4', 6", 0=6c, 0-5s, 5"', 1p and 1"". The paracingular processes, if present, and notably the sulcal processes are also covered by the ectophragm, which hampers the recognition of the exact number of processes in these regions. Between the reflected paraplates thin strands of ectophragm connects the process-complexes distally. The archeopyle is apical (4A). The operculum is compound (4A) and free.
Discussion:
Ectosphaeridiumis morphological similar to Membranilarnacia Eisenack, 1963 emend. Williams and Downi, 1966, Glaphyrocysta Stover and Evitt, 1978 and Eatonicysta Stover and Evitt, 1978, in overall shape and archaeopyle formation. Ectosphaeridium differs from Membranilarnacia in having intratabular process-complexes rather than randomly distributed processes. Glaphyrocysta Stover and Evitt, 1978 differs from Ectosphaeridium in lacking dorsal and ventral processes and an ectophragm. Ectosphaeridium differs from Eatonicysta Stover and Evitt, 1978 in having groups of processes rather than intratabular ones and the possession of an ectophragm.