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Spinidinium ornatum
Spinidinium ornatum (May, 1980) Lentin and Williams, 1981
Originally Deflandrea, subsequently Spinidinium, thirdly Spinidinium? Questionable assignment: Sluijs et al. (2009, p.48).
Holotype: May, 1980, pl.9, figs.3-4
Locus typicus: Atlantic Highlands, New Jersey
Stratum typicum: Campanian-earliest Maastrichtian
Original description: May, 1980, p.77-78: Deflandrea ornata
Periblast peridinioid, slightly rhomboidal, tapering apically from cingulum in nearly linear fashion, forming a relatively short, flatly-truncated, apical horn, bearing a terminal pore; tapering antapically from cingulum to short, slightly conical, pointed, antapical horns. Outline between antapical horns concave. Left antapical horn larger than right. Periphragm generally smooth, and is formed into triangle to trapezoid-shaped, high, sutural fold arrangements; each fold bearing short to long (up to 3 µm), closely spaced, solid, simple to bifurcate spines. The triangular to trapezoidal fields which also may bear intratabular coni, are well separated from each other and outline plate equivalents. The lateral separation of the preand postcingular fields creates marked interruptions in the cingulum. Apical tabulation reflected by a slender diamond-shaped pattern of intratabular coni on the ventral apex, and paired, longitudinal rows of spines extending down the lateral sides of the apex outlining the remaining apical plate fields. Precingular and postcingular series reflected by triangle to trapezoid-shaped, sutural fold arrangements bearing spines; triangular fields on the ventral surface, trapezoidal fields on the lateral and dorsal surfaces. Antapical series marked by rows of spines encompassing the antapical horns, suggesting that the lower portions of each horn represent one plate equivalent. Reflected tabulation 4", ?3a, 7", 6-7c, 5""", 2"""". Endoblast large, angularly ovoidal, closely appressed to periblast, filling nearly all of the central cavity, forming pericoels only within the short horns and under the elevated ridges of the cingulum and plate equivalents. Endophragm smooth, slightly indented along cingulum. Cingulum levorotatory, terminal ends offset ca. one cingulum width; interrupted due to separation of adjacent pre- and postcingular plate equivalents, formed of high sutural folds bearing long spines (up to 3 µm), pericoels occurring beneath the sutural folds. Sulcus extends antapically from between terminal ends of cingulum as two rows of spines which intersect the posterior periblast margin a short distance inward from the antapical horns. At each intersection a small, spike-like projection is directed posteriorly. Archeopyle intercalary (Type Ia/Ia); accessory sutures extend downward along the lateral margins of the 4"". Although most specimens are characteristically like those described in the above paragraph, the high degree of variability in the height of the sutural folds and spines can change greatly the general appearance of the cyst surface. Although cyst outline and plate shapes do not change, the overall relief of the margins of the plates, cingulum, and sulcus may be reduced, the sutural folds being altogether missing, except along the cingulum and sulcus. The spike-like projections at the base of the sulcus may also be lacking.
Discussion: Diagnostic features are the rhomboidal outline, tabulation reflected by variable sutural folds and peritabular spines and occasional to frequent intratabular coni, well-separated plate fields, interrupted cingulum, and accessory sutures extending down lateral margins of 4"""". Dimensions: Holotype: L x W 64 x 45 µm, apical horn above endoblast 16 µm, left antapical horn beneath endoblast 13 µm, spine length up to 3 µm, wall layers, endoblast 1 µm, periblast ca. 1µm. Observed range: (23 specimens) length 53-72 µm, width 39-47 µm.
Affinities:
May, 1980, p.78: Deflandrea ornata
D. ornata is similar to D. sverdrupiana Manum 1963 and D. scheii Manum 1963. Both D. sverdrupiana and D. scheii, however, lack the long, bifurcating spines, spines on the antapical horns, diverging antapical horns. D. sverdrupiana lacks the accessory sutures along the lateral sides of the 4".
Originally Deflandrea, subsequently Spinidinium, thirdly Spinidinium? Questionable assignment: Sluijs et al. (2009, p.48).
Holotype: May, 1980, pl.9, figs.3-4
Locus typicus: Atlantic Highlands, New Jersey
Stratum typicum: Campanian-earliest Maastrichtian
Original description: May, 1980, p.77-78: Deflandrea ornata
Periblast peridinioid, slightly rhomboidal, tapering apically from cingulum in nearly linear fashion, forming a relatively short, flatly-truncated, apical horn, bearing a terminal pore; tapering antapically from cingulum to short, slightly conical, pointed, antapical horns. Outline between antapical horns concave. Left antapical horn larger than right. Periphragm generally smooth, and is formed into triangle to trapezoid-shaped, high, sutural fold arrangements; each fold bearing short to long (up to 3 µm), closely spaced, solid, simple to bifurcate spines. The triangular to trapezoidal fields which also may bear intratabular coni, are well separated from each other and outline plate equivalents. The lateral separation of the preand postcingular fields creates marked interruptions in the cingulum. Apical tabulation reflected by a slender diamond-shaped pattern of intratabular coni on the ventral apex, and paired, longitudinal rows of spines extending down the lateral sides of the apex outlining the remaining apical plate fields. Precingular and postcingular series reflected by triangle to trapezoid-shaped, sutural fold arrangements bearing spines; triangular fields on the ventral surface, trapezoidal fields on the lateral and dorsal surfaces. Antapical series marked by rows of spines encompassing the antapical horns, suggesting that the lower portions of each horn represent one plate equivalent. Reflected tabulation 4", ?3a, 7", 6-7c, 5""", 2"""". Endoblast large, angularly ovoidal, closely appressed to periblast, filling nearly all of the central cavity, forming pericoels only within the short horns and under the elevated ridges of the cingulum and plate equivalents. Endophragm smooth, slightly indented along cingulum. Cingulum levorotatory, terminal ends offset ca. one cingulum width; interrupted due to separation of adjacent pre- and postcingular plate equivalents, formed of high sutural folds bearing long spines (up to 3 µm), pericoels occurring beneath the sutural folds. Sulcus extends antapically from between terminal ends of cingulum as two rows of spines which intersect the posterior periblast margin a short distance inward from the antapical horns. At each intersection a small, spike-like projection is directed posteriorly. Archeopyle intercalary (Type Ia/Ia); accessory sutures extend downward along the lateral margins of the 4"". Although most specimens are characteristically like those described in the above paragraph, the high degree of variability in the height of the sutural folds and spines can change greatly the general appearance of the cyst surface. Although cyst outline and plate shapes do not change, the overall relief of the margins of the plates, cingulum, and sulcus may be reduced, the sutural folds being altogether missing, except along the cingulum and sulcus. The spike-like projections at the base of the sulcus may also be lacking.
Discussion: Diagnostic features are the rhomboidal outline, tabulation reflected by variable sutural folds and peritabular spines and occasional to frequent intratabular coni, well-separated plate fields, interrupted cingulum, and accessory sutures extending down lateral margins of 4"""". Dimensions: Holotype: L x W 64 x 45 µm, apical horn above endoblast 16 µm, left antapical horn beneath endoblast 13 µm, spine length up to 3 µm, wall layers, endoblast 1 µm, periblast ca. 1µm. Observed range: (23 specimens) length 53-72 µm, width 39-47 µm.
Affinities:
May, 1980, p.78: Deflandrea ornata
D. ornata is similar to D. sverdrupiana Manum 1963 and D. scheii Manum 1963. Both D. sverdrupiana and D. scheii, however, lack the long, bifurcating spines, spines on the antapical horns, diverging antapical horns. D. sverdrupiana lacks the accessory sutures along the lateral sides of the 4".