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Dapcodinium ovale
Dapcodinium ovale Below, 1987
Holotype: Below, 1987, pl.24, fig.2,5
Locus typicus: Reichenbach near Aalen, Germany
Stratum typicum: Late Pliensbachian
Translation: Transaltion Bureau, Secretary of State, Canada, p. 363-369
Original description: Below 1987, p. 142-143
Description: Vesicle-/table-arrangement of the dinoflagellate amphiesma PR, 5".
6a, 7"", 8c, 7""", 3"""", as, y, z, ps.
Cyst proximate, acavate, ellipsoidal, ovaloidal, cyst halves of equal size or epicyst slightly shorter than the hypocyst, rounded at the poles, circular to oval in equatorial cross-section. Small. Wall consisting of pedium and low, luxuriate ornaments. Surface smooth, scabrate, widely or densely granulate, granulae anastomosing, fusing, at the equatorial and ventral side, into ribs parallel to the longitudinal axis. Nontabulated, or divided into plates by very fine rows of granulae and ribs. tabulation NR PR/PR, NR"/5", NRa/6a, NR""/7"", Xc, NR"""/7""", NR""""/3"""", Xs,/as, z, y, ps. Tabulation mostly exclusively on epicyst; hypocystal and especially cingular and sulcal areas rarely tabulated. Small apical, pentagonal PR.
- Apical plate series consisting of 5 irregular polyhedrons: steno VI 1" (V), large VI 2" (VVL), VI 3" (DDL), VI 4" (RDR), and VI 5" (VVR).
- Anterior intercalary plate series consisting of 6 irregular polyhedrons: lati VI 1a (L), tiny trigonal 2a (DL), VI 3a (DDL), VII 4a (DR), tiny trigonal 5a (RDR), lati VI 6a (R).
- 7 precingulars: anteriorly geniculate V-nE 1"" (VVL), V-nE 2"" (LVL), V-nE 4"" (D), V-nE 6"" (VR) and V-nE 7"", anteriorly bigeniculate VI-nE 3"" (DL) and VI-nE 5"" RDR). - Cingulum nonpartite, laevorotatory like the late series, equatorially lightly indented, as a broad, mostly smooth or faintly ornamented band with absolutely straight and parallel cingular margins, enforced by ornaments.
- 7 postcingulars: posteriorly linear V-nE 1""" (VVL), IV-nE 2""" (VL), IV-nE 4""" (DL), IV-nE 6""" (RDR) and V-nE7""" (VVR), posteriorly geniculate V-nE 3""" (L) and V-nE 5""" (D). 3 large antapicals: VII 1"""" (VL), V 2"""" (DL) and VI 3"""".
- Sulcus partially subdivided into small as, central sulcus, y, long narrow z and sigmoidal ps.
- Archaeopyle\ complex, consisting ofapicals and anterior intercalaries: PR+2"+3"+4"+1a+2a+3a+4a. Operculum solvate, secate, general opercular formula PR(s)+2"(s)+3"(s)+4"(s)+1a(s)+2a(s)+3a(s)+4a(s).
Dimensions of holotype: length 41 Ám, width 33 Ám, thickness 33 Ám.
Affinities:
Below 1987, p. 143-144
(annotated) The elongate D. ovale differs from the spherical D. priscum and from the polygonal D. polyedricum. Most common are forms with equal width and thickness, dorso-ventrally flattened forms are rare. In contrast to the cyst shape, the surface ornamentation varies widely: all transitions between smooth and scabrate surfaces to surfaces with thickened granulae, mostly widely and irregularly spaced. Closely spaced granulae fuse into rows or groups of various lengths. The forms covered with very densely spaced, firms granulae (var. granulatum) dominate the younger associations from the Toarcian and Aalenian.
In contrast to D. polyedricum, D. ovale has two more, tiny, trigonal anterior intercalaries.
In D. ovale, a maximum of 7 plates is involved in archaeopyle formation, mostly 3", 4", 3a and 4a. Often PR is removed, 2" in 25% of the cases, 1a and 2a rarely. The operculum is solvate. Thus, 56 different possibilities of archaeopyle formation are presented.
Holotype: Below, 1987, pl.24, fig.2,5
Locus typicus: Reichenbach near Aalen, Germany
Stratum typicum: Late Pliensbachian
Translation: Transaltion Bureau, Secretary of State, Canada, p. 363-369
Original description: Below 1987, p. 142-143
Description: Vesicle-/table-arrangement of the dinoflagellate amphiesma PR, 5".
6a, 7"", 8c, 7""", 3"""", as, y, z, ps.
Cyst proximate, acavate, ellipsoidal, ovaloidal, cyst halves of equal size or epicyst slightly shorter than the hypocyst, rounded at the poles, circular to oval in equatorial cross-section. Small. Wall consisting of pedium and low, luxuriate ornaments. Surface smooth, scabrate, widely or densely granulate, granulae anastomosing, fusing, at the equatorial and ventral side, into ribs parallel to the longitudinal axis. Nontabulated, or divided into plates by very fine rows of granulae and ribs. tabulation NR PR/PR, NR"/5", NRa/6a, NR""/7"", Xc, NR"""/7""", NR""""/3"""", Xs,/as, z, y, ps. Tabulation mostly exclusively on epicyst; hypocystal and especially cingular and sulcal areas rarely tabulated. Small apical, pentagonal PR.
- Apical plate series consisting of 5 irregular polyhedrons: steno VI 1" (V), large VI 2" (VVL), VI 3" (DDL), VI 4" (RDR), and VI 5" (VVR).
- Anterior intercalary plate series consisting of 6 irregular polyhedrons: lati VI 1a (L), tiny trigonal 2a (DL), VI 3a (DDL), VII 4a (DR), tiny trigonal 5a (RDR), lati VI 6a (R).
- 7 precingulars: anteriorly geniculate V-nE 1"" (VVL), V-nE 2"" (LVL), V-nE 4"" (D), V-nE 6"" (VR) and V-nE 7"", anteriorly bigeniculate VI-nE 3"" (DL) and VI-nE 5"" RDR). - Cingulum nonpartite, laevorotatory like the late series, equatorially lightly indented, as a broad, mostly smooth or faintly ornamented band with absolutely straight and parallel cingular margins, enforced by ornaments.
- 7 postcingulars: posteriorly linear V-nE 1""" (VVL), IV-nE 2""" (VL), IV-nE 4""" (DL), IV-nE 6""" (RDR) and V-nE7""" (VVR), posteriorly geniculate V-nE 3""" (L) and V-nE 5""" (D). 3 large antapicals: VII 1"""" (VL), V 2"""" (DL) and VI 3"""".
- Sulcus partially subdivided into small as, central sulcus, y, long narrow z and sigmoidal ps.
- Archaeopyle\ complex, consisting ofapicals and anterior intercalaries: PR+2"+3"+4"+1a+2a+3a+4a. Operculum solvate, secate, general opercular formula PR(s)+2"(s)+3"(s)+4"(s)+1a(s)+2a(s)+3a(s)+4a(s).
Dimensions of holotype: length 41 Ám, width 33 Ám, thickness 33 Ám.
Affinities:
Below 1987, p. 143-144
(annotated) The elongate D. ovale differs from the spherical D. priscum and from the polygonal D. polyedricum. Most common are forms with equal width and thickness, dorso-ventrally flattened forms are rare. In contrast to the cyst shape, the surface ornamentation varies widely: all transitions between smooth and scabrate surfaces to surfaces with thickened granulae, mostly widely and irregularly spaced. Closely spaced granulae fuse into rows or groups of various lengths. The forms covered with very densely spaced, firms granulae (var. granulatum) dominate the younger associations from the Toarcian and Aalenian.
In contrast to D. polyedricum, D. ovale has two more, tiny, trigonal anterior intercalaries.
In D. ovale, a maximum of 7 plates is involved in archaeopyle formation, mostly 3", 4", 3a and 4a. Often PR is removed, 2" in 25% of the cases, 1a and 2a rarely. The operculum is solvate. Thus, 56 different possibilities of archaeopyle formation are presented.