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Microdinium horridum
Microdinium? horridum (Below, 1987) Lentin and Williams, 1989
Originally Phanerodinium, subsequently (and now) Microdinium?.
Lentin and Williams, 1993, did not follow Marheinecke, 1992, who retained this species in Phanerodinium Deflandre, 1937.
At the time of the transfer, Lentin and Williams, 1989, questionably included this species in Microdinium.
Holotype: Below, 1987, pl.17, fig.1-6p.; Fensome e al., 1993, p. 1229
Locus typicus: Wissant, Boulonnais, France
Stratum typicum: Middle Albian
Original description: Below 1987b, p. 49-50: Phanerodinium horridum
Vesicle/plate arrangement on amphiesma cop, pop, cap, 4", 4a, 7"", 7c, 6""", 2"""", as, FM subdivided into peri- flagellar platelets, ls, rs, ps; pentagonal 1"""" and hexagonal 2"""" partiform; omegaform ps very large; adelopore on suture 1"/4". Growth of thecal plates gonyaulacoidal. Cyst proximochorate, acavate, polyhedral, extremely lenticular with parallel dorsal and ventral sides, epicyst very small, flattened-tholiform, hypocyst 4-6 times as long, prismatic and antapically roof-shaped, maximal diameter at the posterior cingular margin; size small; wall composed of thin pedium and fibrose luxuria fused distally into a tegillum connected by fibers wich are very low on intraareate spaces and sometimes reduced to granules or absent, but long on the limbi, bridging the entire finate pericoel; surface of tegillum scabrate to levigate; on the fines, the tegillum forms very low ridges between areae, but between large areae it forms carinate, distally glabrous ribs produced gonally into high, broad-based, distally acuminate spines; paratabulation cop, pop, cap, 4", 4a, 7"", 7c, 6""", 2"""", as, FM, ls, rs, ps; cop very small, circular, surrounded by annular pop, small planate cap (V); very small apicals, steno VII 1" (V), VIII 2" (L), VIII 3" (R), steno V 4" (VVR) with porichnion on finis 4"/1"; 4 very small anterior intercalaries, caroidal 1a (DL), fastigiate 2a (D), deltaform inverse-camerate 3a (DR), V 4a (RVR); 7 precingulars, anteriorly geniculate V-nE 1"" (VVL), V-nE 2"" (L), V-nE 3"" (DDL), V-nE 4"" (DDR), V-nE 5"" (R) and V-nE 6"" (VR), small anteriorly geniculate V-nE 7"" (VVR); finis 3""/4"" often dorsal; cingulum planispiral, beginning and end of cingulum forming a shallow v-shaped configuration with the sulcus, shallowly indented or level, heptapartite, lati 1c to 6c, iso fastigiate 7c; 6 very large steno postcingulars, posterior linear V-nE 1""" (VVL) and IV-nE 2""" (VL), posteriorly geniculate V-nE 3""" (DL), posteriorly linear IV-nE 4""" (DDR), IV-nE 5""" and V-nE 6""" (VR); 2 quasi-planar antapicals descending laterally on each side of the pole, V 1"""" (L), VI 2"""" R; sulcus level or lightly indented on the hypocyst, partite, small VI as, small oval FM subdivided into several very small eareae, small V ls, small V rs, large deltaform fastigiate ps; archaeopyle 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.
Dimensions of holotype: Length 46 Ám, Breath 47 Ám, Thickness 20 Ám.
Originally Phanerodinium, subsequently (and now) Microdinium?.
Lentin and Williams, 1993, did not follow Marheinecke, 1992, who retained this species in Phanerodinium Deflandre, 1937.
At the time of the transfer, Lentin and Williams, 1989, questionably included this species in Microdinium.
Holotype: Below, 1987, pl.17, fig.1-6p.; Fensome e al., 1993, p. 1229
Locus typicus: Wissant, Boulonnais, France
Stratum typicum: Middle Albian
Original description: Below 1987b, p. 49-50: Phanerodinium horridum
Vesicle/plate arrangement on amphiesma cop, pop, cap, 4", 4a, 7"", 7c, 6""", 2"""", as, FM subdivided into peri- flagellar platelets, ls, rs, ps; pentagonal 1"""" and hexagonal 2"""" partiform; omegaform ps very large; adelopore on suture 1"/4". Growth of thecal plates gonyaulacoidal. Cyst proximochorate, acavate, polyhedral, extremely lenticular with parallel dorsal and ventral sides, epicyst very small, flattened-tholiform, hypocyst 4-6 times as long, prismatic and antapically roof-shaped, maximal diameter at the posterior cingular margin; size small; wall composed of thin pedium and fibrose luxuria fused distally into a tegillum connected by fibers wich are very low on intraareate spaces and sometimes reduced to granules or absent, but long on the limbi, bridging the entire finate pericoel; surface of tegillum scabrate to levigate; on the fines, the tegillum forms very low ridges between areae, but between large areae it forms carinate, distally glabrous ribs produced gonally into high, broad-based, distally acuminate spines; paratabulation cop, pop, cap, 4", 4a, 7"", 7c, 6""", 2"""", as, FM, ls, rs, ps; cop very small, circular, surrounded by annular pop, small planate cap (V); very small apicals, steno VII 1" (V), VIII 2" (L), VIII 3" (R), steno V 4" (VVR) with porichnion on finis 4"/1"; 4 very small anterior intercalaries, caroidal 1a (DL), fastigiate 2a (D), deltaform inverse-camerate 3a (DR), V 4a (RVR); 7 precingulars, anteriorly geniculate V-nE 1"" (VVL), V-nE 2"" (L), V-nE 3"" (DDL), V-nE 4"" (DDR), V-nE 5"" (R) and V-nE 6"" (VR), small anteriorly geniculate V-nE 7"" (VVR); finis 3""/4"" often dorsal; cingulum planispiral, beginning and end of cingulum forming a shallow v-shaped configuration with the sulcus, shallowly indented or level, heptapartite, lati 1c to 6c, iso fastigiate 7c; 6 very large steno postcingulars, posterior linear V-nE 1""" (VVL) and IV-nE 2""" (VL), posteriorly geniculate V-nE 3""" (DL), posteriorly linear IV-nE 4""" (DDR), IV-nE 5""" and V-nE 6""" (VR); 2 quasi-planar antapicals descending laterally on each side of the pole, V 1"""" (L), VI 2"""" R; sulcus level or lightly indented on the hypocyst, partite, small VI as, small oval FM subdivided into several very small eareae, small V ls, small V rs, large deltaform fastigiate ps; archaeopyle 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.
Dimensions of holotype: Length 46 Ám, Breath 47 Ám, Thickness 20 Ám.