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Trinovantedinium concretum
Trinovantedinium concretum Reid, 1977
Originally Trinovantedinium, subsequently (and now) Quinquecuspis, thirdly Lejeunecysta.
Motile equivalent: Protoperidinium leonis (Pavillard, 1916) Balech, 1974, according to Harland (1981, p.68) and Lewis et al. (1984, p.30).
Holotype: Reid, 1977, pl.1, figs.9-11; Fensome et al., 1993, p.1069, fig.1-3
Locus typicus: Harwich, England
Stratum typicum: Holocene
Original diagnosis: Reid, 1977, p.438
Test pentagonal in dorsoventral view with deep ventral sulcus, pronounced lateral apophyses and widely spaced antapical horns separated by a shallow antapical depression. Girdle equatorial, wide, excavated, inclined, slightly displaced and marked by semicontinuous ridge like thickenings of the wall. Wall thick 1-2.5 µm irregular in optical section with a microgranular or granular surface. Archeopyle intercalary.
Original description: Reid, 1977, p.439
The test is compressed dorsoventrally and is generally bilaterally symmetrical. It is concavo-convex in polar view and has pronounced lateral apophyses clearly visible in lateral view. The epitract is usually concave but may have a shoulder and the hypotract is always concave. A triangular thickening of the wall at the apex shows the position of the apical pore in the thecate stage. Two rounded horns are found at the antapex. The surface is generally microgranular, but may be covered by scattered larger granules. The ventral sulcus appears to extend on to the epitract. It has two central thickenings of the wall at the position of the flagellar scars. Sutures may occasionally be indicated by cracks, but generally the test breaks up along irregular lines. The archeopyle has a rounded subtriangular shape.
Size: Holotype: length 71 µm. Range of 16 specimens: length 60-80 µm, breadth 63-82 µm, thickness 49-61 µm, width of cingulum 7 µm, distance between antapical horn tips 25-28 µm, width of archeopyle 23-25 µm, length ("height") of archeopyle 23-28 µm.
Originally Trinovantedinium, subsequently (and now) Quinquecuspis, thirdly Lejeunecysta.
Motile equivalent: Protoperidinium leonis (Pavillard, 1916) Balech, 1974, according to Harland (1981, p.68) and Lewis et al. (1984, p.30).
Holotype: Reid, 1977, pl.1, figs.9-11; Fensome et al., 1993, p.1069, fig.1-3
Locus typicus: Harwich, England
Stratum typicum: Holocene
Original diagnosis: Reid, 1977, p.438
Test pentagonal in dorsoventral view with deep ventral sulcus, pronounced lateral apophyses and widely spaced antapical horns separated by a shallow antapical depression. Girdle equatorial, wide, excavated, inclined, slightly displaced and marked by semicontinuous ridge like thickenings of the wall. Wall thick 1-2.5 µm irregular in optical section with a microgranular or granular surface. Archeopyle intercalary.
Original description: Reid, 1977, p.439
The test is compressed dorsoventrally and is generally bilaterally symmetrical. It is concavo-convex in polar view and has pronounced lateral apophyses clearly visible in lateral view. The epitract is usually concave but may have a shoulder and the hypotract is always concave. A triangular thickening of the wall at the apex shows the position of the apical pore in the thecate stage. Two rounded horns are found at the antapex. The surface is generally microgranular, but may be covered by scattered larger granules. The ventral sulcus appears to extend on to the epitract. It has two central thickenings of the wall at the position of the flagellar scars. Sutures may occasionally be indicated by cracks, but generally the test breaks up along irregular lines. The archeopyle has a rounded subtriangular shape.
Size: Holotype: length 71 µm. Range of 16 specimens: length 60-80 µm, breadth 63-82 µm, thickness 49-61 µm, width of cingulum 7 µm, distance between antapical horn tips 25-28 µm, width of archeopyle 23-25 µm, length ("height") of archeopyle 23-28 µm.