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Microdinium reteinvolvatum
From Fensome et al., 2019:
Microdinium? reteinvolvatum (Below, 1987b, p.51–52, pl.12, figs.3,8) Lentin and Williams, 1989, p.245. Holotype: Below, 1987b, pl.12, fig.3; Fensome et al., 1993a, fig.1 — p.1297. Originally Phanerodinium, subsequently (and now) Microdinium?. Questionable assignment: Lentin and Williams (1989, p.245). Age: middle–late Albian.
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Locus typicus: The coastal section between Wissant and Strouane, Boulonnais, France
Stratum typicum: Middle Albian
Translation Below, 1987: Fensome et al., 1993
Original description: Below, 1987, p.51: Phanerodinium reteinvolvatum
Arrangement of vesicles/plates on the dinoflagellate amphiesma cop, pop, cap, 4', 4a, 7", 7c, 6''', 2'''', as, FM subdivided into several periflagellar platelets, ls, rs, ps; pentagonal 1'''' and hexagonal 2'''' partiform; omegaform ps very large; adelopore on suture 1'/4'; growth of plates gonyaulacoid.
Cyst form proximate, acavate, spheroidal, hypocyst twice as long as epicyst, equatorially circular; size small; wall composed of thin pedium and firm, spongy luxuria, surface glazed to a tegillate reticulum of variable mesh size, fines marked by narrow, deep furrows in the luxuria; areation formula cop, pop, cap, 4', 4a, 7", 7c, 6''', 2'''', as, FM, ls, rs, ps; cop very small, circular, surrounded by an annular pop, small planate cap (V); 4 small apicals, steno VII 1' (V), VIII 2' (L), VIII 3' (R), steno V 4' (VVR); 4 small anterior intercalaries, caroidal la (DL), fastigiate 2a (D), deltaform inversecamerate 3a (DR),V 4a (RVR); 7 precingulars, anteriorly geniculate V-nE 1" (VVL), anteriorly geniculate V-nE 2" (L), anteriorly geniculate V-nE 3" (DDL), anteriorly geniculate V-nE 4" (DDR), finis 3"/4" approximately dorsal, anteriorly geniculate V-nE 5"(R), anteriorly geniculate V-nE 6" (VR), small anteriorly geniculate V-nE 7" (VVR); cingulum helicoid laevorotatory, level, heptapartite, lati 1c to 6c, isofastigiate 7c; 6 postcingulars, posteriorly linear V-nE 1''' (VVL), posteriorly linear IV-nE 2''' (VL), posteriorly geniculate V-nE 3''' (DL), posteriorly linear IV-nE 4''' (DDR), posteriorly linear IV-nE 5'''(R), posteriorly linear V-nE 6''' (VR); 2 antapicals partiform, V 1'''' descending towards VL, VI 2'''' towards R; sulcus level, partite, small VI as, small oval FM often subdivided into very small areae, small V ls, small V rs, large omegaform VI ps; archeopyle apical/anterior intercalary, PR+1'+ 2' + 3' + 4' + 1a + 2a + 3a + 4a; operculum foederate, adnate, general opercular formula (PR+1'+ 2' + 3' + 4' + 1a + 2a + 3a + 4a)[a].
Size: Holotype: length 34 µm, breadth 34 µm, thickness 34 µm.
Microdinium? reteinvolvatum (Below, 1987b, p.51–52, pl.12, figs.3,8) Lentin and Williams, 1989, p.245. Holotype: Below, 1987b, pl.12, fig.3; Fensome et al., 1993a, fig.1 — p.1297. Originally Phanerodinium, subsequently (and now) Microdinium?. Questionable assignment: Lentin and Williams (1989, p.245). Age: middle–late Albian.
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Locus typicus: The coastal section between Wissant and Strouane, Boulonnais, France
Stratum typicum: Middle Albian
Translation Below, 1987: Fensome et al., 1993
Original description: Below, 1987, p.51: Phanerodinium reteinvolvatum
Arrangement of vesicles/plates on the dinoflagellate amphiesma cop, pop, cap, 4', 4a, 7", 7c, 6''', 2'''', as, FM subdivided into several periflagellar platelets, ls, rs, ps; pentagonal 1'''' and hexagonal 2'''' partiform; omegaform ps very large; adelopore on suture 1'/4'; growth of plates gonyaulacoid.
Cyst form proximate, acavate, spheroidal, hypocyst twice as long as epicyst, equatorially circular; size small; wall composed of thin pedium and firm, spongy luxuria, surface glazed to a tegillate reticulum of variable mesh size, fines marked by narrow, deep furrows in the luxuria; areation formula cop, pop, cap, 4', 4a, 7", 7c, 6''', 2'''', as, FM, ls, rs, ps; cop very small, circular, surrounded by an annular pop, small planate cap (V); 4 small apicals, steno VII 1' (V), VIII 2' (L), VIII 3' (R), steno V 4' (VVR); 4 small anterior intercalaries, caroidal la (DL), fastigiate 2a (D), deltaform inversecamerate 3a (DR),V 4a (RVR); 7 precingulars, anteriorly geniculate V-nE 1" (VVL), anteriorly geniculate V-nE 2" (L), anteriorly geniculate V-nE 3" (DDL), anteriorly geniculate V-nE 4" (DDR), finis 3"/4" approximately dorsal, anteriorly geniculate V-nE 5"(R), anteriorly geniculate V-nE 6" (VR), small anteriorly geniculate V-nE 7" (VVR); cingulum helicoid laevorotatory, level, heptapartite, lati 1c to 6c, isofastigiate 7c; 6 postcingulars, posteriorly linear V-nE 1''' (VVL), posteriorly linear IV-nE 2''' (VL), posteriorly geniculate V-nE 3''' (DL), posteriorly linear IV-nE 4''' (DDR), posteriorly linear IV-nE 5'''(R), posteriorly linear V-nE 6''' (VR); 2 antapicals partiform, V 1'''' descending towards VL, VI 2'''' towards R; sulcus level, partite, small VI as, small oval FM often subdivided into very small areae, small V ls, small V rs, large omegaform VI ps; archeopyle apical/anterior intercalary, PR+1'+ 2' + 3' + 4' + 1a + 2a + 3a + 4a; operculum foederate, adnate, general opercular formula (PR+1'+ 2' + 3' + 4' + 1a + 2a + 3a + 4a)[a].
Size: Holotype: length 34 µm, breadth 34 µm, thickness 34 µm.