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Mikrocysta granulata
From Fensome et al., 2019:
Mikrocysta granulata Below, 1987b, p.18–19, pl.3, figs.12–15. Holotype: Below, 1987b, pl.3, figs.13,15; Fensome et al.,
1993a, figs.2,4 — p.1223. Age: late Pliensbachian–Toarcian.
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Locus typicus: Botneheia Plateau, Spitsbergen
Stratum typicum: Toarcian
Translation Below, 1987: Secretary of State, Canada, Translation Bureau
Original description: Below, 1987, p. 18-19
Diagnosis: Arrangement of vesicles/plates of the dinoflagellate amphiesma PR, 5’, 3a- 5a, 7’’, 7c, 6’’’, 2’’’’, 2as, FM with periflagellar platelets, ls, rs, ps; pentagonal 1’’’’ and hexagonal 2’’’’ partiform; omegaform ps very large. Cyst habit proximate, acavate, comparable to a lenticualr hyperboloid rounded at the poles, the transversely ellipsoidal epicyst of lesser height and breadth than the transversely ellipsoidal hypocyst, the two halves distinctly separated by a sometimes deeply indented, very broad, weakly helicoid laevorotatory cingulum; sulcus level or shallowly indented on the hypocyst; size small; wall composed of thin pedium, luxuria comprising only very coarse, seldom fused grains of uniform density, nonareate; areation formula NR PR, NR’, NR2’, 3’arch, 4’arch, NR5’, NRa, NRc/Xc, NR’’’, NR’’’’, NRs/xs; archeopyle apical, amplificate, 3’ + 4’; operculum solvate, secate, general opercular formula 3’s + 4’s.
Dimensions of Holotype: Length 39 µm, breadth 33 µm, thickness 24 µm.
Remarks: Because of the amplificate opercular plates, the archeopyle is nearly circular. In contrast to Mikrocysta erugata, in which one of the two opercular pieces was occasionally found in situ, in the material of Mikrocysta granulata n. sp. at my disposal the exit hole was always fully formed, so that evidence of a solvate or a foederate operculum could not be had. Therefore the opercular formula was inferred by analogy with Mikrocysta erugata.
Mikrocysta granulata Below, 1987b, p.18–19, pl.3, figs.12–15. Holotype: Below, 1987b, pl.3, figs.13,15; Fensome et al.,
1993a, figs.2,4 — p.1223. Age: late Pliensbachian–Toarcian.
---------------------------------------------------------------------------------------------------
Locus typicus: Botneheia Plateau, Spitsbergen
Stratum typicum: Toarcian
Translation Below, 1987: Secretary of State, Canada, Translation Bureau
Original description: Below, 1987, p. 18-19
Diagnosis: Arrangement of vesicles/plates of the dinoflagellate amphiesma PR, 5’, 3a- 5a, 7’’, 7c, 6’’’, 2’’’’, 2as, FM with periflagellar platelets, ls, rs, ps; pentagonal 1’’’’ and hexagonal 2’’’’ partiform; omegaform ps very large. Cyst habit proximate, acavate, comparable to a lenticualr hyperboloid rounded at the poles, the transversely ellipsoidal epicyst of lesser height and breadth than the transversely ellipsoidal hypocyst, the two halves distinctly separated by a sometimes deeply indented, very broad, weakly helicoid laevorotatory cingulum; sulcus level or shallowly indented on the hypocyst; size small; wall composed of thin pedium, luxuria comprising only very coarse, seldom fused grains of uniform density, nonareate; areation formula NR PR, NR’, NR2’, 3’arch, 4’arch, NR5’, NRa, NRc/Xc, NR’’’, NR’’’’, NRs/xs; archeopyle apical, amplificate, 3’ + 4’; operculum solvate, secate, general opercular formula 3’s + 4’s.
Dimensions of Holotype: Length 39 µm, breadth 33 µm, thickness 24 µm.
Remarks: Because of the amplificate opercular plates, the archeopyle is nearly circular. In contrast to Mikrocysta erugata, in which one of the two opercular pieces was occasionally found in situ, in the material of Mikrocysta granulata n. sp. at my disposal the exit hole was always fully formed, so that evidence of a solvate or a foederate operculum could not be had. Therefore the opercular formula was inferred by analogy with Mikrocysta erugata.