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Lithodinia jurassica ssp. jurassica
Lithodinia jurassica ssp. jurassica
Autonym.
Holotype: Eisenack, 1935, pl.4, fig.5
Locus typicus: Eastern Prussia
Stratum typicum: Callovian
Translations Eisenack, 1935 and Gocht, 1975: LPP
Original description: Eisenack 1935, p.175-177
(annotated) Body mostly polyhedral and in dorsal or ventral view a slightly elongate hexagon with more or less convex sides; occasionally spherical. Hypocyst as large as or slightly higher than epicyst. Cingulum clear, but quite flat. Sulcus hardly discernible, apparently extremely flat. In equatorial section ring-shaped. Equatorial plates (pre- and post-cingulars) remarkably large and vaulted trapezoid. One antapical plate, quadrate to trapezoid. Apical and antapical plates flat, the latter parallel to the equatorial plane. Sutures, with the exception of some at the apex, marked by septa, that may be developed weakly to strongly and finely to coarsely. When strongly developed, the septa indicating the cingulum are only present at the antapical side. In the specimens with weakly developed crests, the projections are distally furcate. In specimens with more strongly developed septa, these septa are either finely or coarsely dentate. These forms are described as L. jurassica var. ornata. The specimen drawn shows the following tabulation: 4ap + 5pr + ?g + 5pst + 1p + 1at. The apex is sealed by an apex-platelet. I suspect that the apical plates bordering the sulcus (1" and 2") are not always separated and form the "rhomboid plate".
Emended diagosis: Gocht 1975, p.355
Body ovoidal to polygonal, dorsoventrally lightly compressed. Cingulum slightly, sulcus more strongly indented. Left end of paracingulum displaced one time its breadth. Apical plates 2" and 3" broadly pentagonal, 1" and 4" narrower and more diamond-shaped. Pre- and post-cingular plates large on dorsal and lateral sides, ventrally somewhat smaller. 4-5-sided antapical plate. Plate 1p included in the sulcus. Sulcus undifferentiated, with central flagellar mark. Cingular plates with partially oblique corners; in the direction of the body axis slightly displaced. Reflected tabulation: 4", 6"", 6c, 5""", 1p, 1""""; Lf. Sutures marked by rows of short processes, standing isolated on the ventral side, dorsally and laterally often connected at their bases. Single processes also present on remaning surface.
Wall layers (peri- and endo-phragm) separated; the narrow pericoel bridged by pillar- or septa-shaped supporting elements, sometimes filled except for small cavities. Archaeopyle formed by isolation of the 4 apical plates. Serrate archaeopyle-margin, reflecting the strongly dentate contact of apical and precingular plates.
Dimensions: Holotype 66 Ám long, 63 Ám broad. Other specimens 53(59)73 Ám long, 47(56)66 Ám broad. Processes 2-7 Ám long.
Affinities:
Gocht, 1975, p. 356: (annotated) Gocht 1970 briefly described forms from the Bathonian of NW Germany under L. jurassica. In contrast to the type material of Eisenack, 1935, this material showed a considerable variability, especially in sutural crests and surface ornamentation. Often the body was more elongate compared to the type material. The tabulation was the same as in the original material, only in the sulcal region additional tabulation could be observed.
There is a similarity with L. deflandrei (Meiourogonyaulax d.) in the possession of 5 postcingular plates and in the displacement of the cingular plates in the directon of the longitudinal axis. However, L. deflandrei is more strongly differentiated (plates 2p, pv).
Autonym.
Holotype: Eisenack, 1935, pl.4, fig.5
Locus typicus: Eastern Prussia
Stratum typicum: Callovian
Translations Eisenack, 1935 and Gocht, 1975: LPP
Original description: Eisenack 1935, p.175-177
(annotated) Body mostly polyhedral and in dorsal or ventral view a slightly elongate hexagon with more or less convex sides; occasionally spherical. Hypocyst as large as or slightly higher than epicyst. Cingulum clear, but quite flat. Sulcus hardly discernible, apparently extremely flat. In equatorial section ring-shaped. Equatorial plates (pre- and post-cingulars) remarkably large and vaulted trapezoid. One antapical plate, quadrate to trapezoid. Apical and antapical plates flat, the latter parallel to the equatorial plane. Sutures, with the exception of some at the apex, marked by septa, that may be developed weakly to strongly and finely to coarsely. When strongly developed, the septa indicating the cingulum are only present at the antapical side. In the specimens with weakly developed crests, the projections are distally furcate. In specimens with more strongly developed septa, these septa are either finely or coarsely dentate. These forms are described as L. jurassica var. ornata. The specimen drawn shows the following tabulation: 4ap + 5pr + ?g + 5pst + 1p + 1at. The apex is sealed by an apex-platelet. I suspect that the apical plates bordering the sulcus (1" and 2") are not always separated and form the "rhomboid plate".
Emended diagosis: Gocht 1975, p.355
Body ovoidal to polygonal, dorsoventrally lightly compressed. Cingulum slightly, sulcus more strongly indented. Left end of paracingulum displaced one time its breadth. Apical plates 2" and 3" broadly pentagonal, 1" and 4" narrower and more diamond-shaped. Pre- and post-cingular plates large on dorsal and lateral sides, ventrally somewhat smaller. 4-5-sided antapical plate. Plate 1p included in the sulcus. Sulcus undifferentiated, with central flagellar mark. Cingular plates with partially oblique corners; in the direction of the body axis slightly displaced. Reflected tabulation: 4", 6"", 6c, 5""", 1p, 1""""; Lf. Sutures marked by rows of short processes, standing isolated on the ventral side, dorsally and laterally often connected at their bases. Single processes also present on remaning surface.
Wall layers (peri- and endo-phragm) separated; the narrow pericoel bridged by pillar- or septa-shaped supporting elements, sometimes filled except for small cavities. Archaeopyle formed by isolation of the 4 apical plates. Serrate archaeopyle-margin, reflecting the strongly dentate contact of apical and precingular plates.
Dimensions: Holotype 66 Ám long, 63 Ám broad. Other specimens 53(59)73 Ám long, 47(56)66 Ám broad. Processes 2-7 Ám long.
Affinities:
Gocht, 1975, p. 356: (annotated) Gocht 1970 briefly described forms from the Bathonian of NW Germany under L. jurassica. In contrast to the type material of Eisenack, 1935, this material showed a considerable variability, especially in sutural crests and surface ornamentation. Often the body was more elongate compared to the type material. The tabulation was the same as in the original material, only in the sulcal region additional tabulation could be observed.
There is a similarity with L. deflandrei (Meiourogonyaulax d.) in the possession of 5 postcingular plates and in the displacement of the cingular plates in the directon of the longitudinal axis. However, L. deflandrei is more strongly differentiated (plates 2p, pv).