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Microdinium densigranulatum
Microdinium densigranulatum (Below, 1987) Lentin and Williams, 1989
Originally Phanerodinium, subsequently (and now) Microdinium.
Holotype: Below, 1987, pl 13, figs 6-10; Fensome et al., 1993, p.1119, figs.1-5
Locus typicus: Between Wissant and Strouane, Boulonnais, France
Stratum typicum: Middle Albian
Translation Below, 1987: Fensome et al., 1993
Original description: Below, 1987, p.45: Phanerodinium densigranulatum
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 to proximochorate, acavate, spheroidal to ovaloidal, hypocyst twice as long as epicyst, equatorial section circular, maximum diameter at the posterior cingular margin; size small, wall composed of thin pedium and luxuria, which forms sometimes very densely packed granules or short baculi as well as low, finate ridges; the ridges comprise rows of distally fused setae and long baculi at close, but variable intervals; height of intraareate and finate ornaments very variable; areation formula NR PR/X PR, NR"/X", NRa/Xa, 7", 7c, 6""", 2"""", as, NR FM/X FM, ls, rs, ps; areation absent or rudimentary on apical and anterior intercalary regions; 7 precingulars, anteriorly geniculate V-nE 1" (VVL), anteriorly geniculate VnE 2n (L), anteriorly geniculate V-nE 3" (DDL), anteriorly geniculate V-nE 4" (DDR), finis 3"/4" characteristically dorsal, anteriorly geniculate V-nE 5" (R), anteriorly geniculate V-nE 6" (VR), small anteriorly geniculate V-nE 7" (VVR); cingulum level, very slightly helicoid laevorotatory, 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, non-partite or small VI as, small oval FM not, or rudimentarily, subdivided into several very small areae, small V ls, small V rs, large omegaform VI ps, archeopyle apical/anterior intercalary, PR + 1" + 2" + 3" + 4" + la + 2a + 3a + 4a; operculum foederate, adnate, general opercular formula (PR + 1" + 2" + 3" + 4" + 1a + 2a + 3a + 4a).
Size: Holotype: length 34 Ám, breadth 29 Ám, thickness 27 Ám.
Originally Phanerodinium, subsequently (and now) Microdinium.
Holotype: Below, 1987, pl 13, figs 6-10; Fensome et al., 1993, p.1119, figs.1-5
Locus typicus: Between Wissant and Strouane, Boulonnais, France
Stratum typicum: Middle Albian
Translation Below, 1987: Fensome et al., 1993
Original description: Below, 1987, p.45: Phanerodinium densigranulatum
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 to proximochorate, acavate, spheroidal to ovaloidal, hypocyst twice as long as epicyst, equatorial section circular, maximum diameter at the posterior cingular margin; size small, wall composed of thin pedium and luxuria, which forms sometimes very densely packed granules or short baculi as well as low, finate ridges; the ridges comprise rows of distally fused setae and long baculi at close, but variable intervals; height of intraareate and finate ornaments very variable; areation formula NR PR/X PR, NR"/X", NRa/Xa, 7", 7c, 6""", 2"""", as, NR FM/X FM, ls, rs, ps; areation absent or rudimentary on apical and anterior intercalary regions; 7 precingulars, anteriorly geniculate V-nE 1" (VVL), anteriorly geniculate VnE 2n (L), anteriorly geniculate V-nE 3" (DDL), anteriorly geniculate V-nE 4" (DDR), finis 3"/4" characteristically dorsal, anteriorly geniculate V-nE 5" (R), anteriorly geniculate V-nE 6" (VR), small anteriorly geniculate V-nE 7" (VVR); cingulum level, very slightly helicoid laevorotatory, 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, non-partite or small VI as, small oval FM not, or rudimentarily, subdivided into several very small areae, small V ls, small V rs, large omegaform VI ps, archeopyle apical/anterior intercalary, PR + 1" + 2" + 3" + 4" + la + 2a + 3a + 4a; operculum foederate, adnate, general opercular formula (PR + 1" + 2" + 3" + 4" + 1a + 2a + 3a + 4a).
Size: Holotype: length 34 Ám, breadth 29 Ám, thickness 27 Ám.