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Deflandrea microarma
Deflandrea microarma McIntyre, 1975
Now Isabelidinium. Originally Deflandrea, subsequently (and now) Isabelidinium. See also Isabelia (combination illegitimate).
Holotype: McIntyre, 1975, pl.1, figs.5,6
Locus typicus: Horton River, Northwest Territories, Canada
Stratum typicum: Campanian-Maastrichtian
Original diagnosis: McIntyre, 1975, p.65
Cyst cavate, convex in equatorial region, with approximately equal-sized epitract and hypotract. Periphragm usually folded in equatorial region, but a definite cingulum is not present. Indications of a large, wide sulcus on the ventral surface are seen occasionally. On the epitract the periblast bulges laterally above the endoblast to form small angular or sometimes rounded shoulders, on which a short, broad apical horn is situated. Apical horn usually round or blunt at the end, but occasionally has a short papilla (Pl. 1, fig. 5). Left antapical horn short, 8-12 µm long and either pointed (Pl. 1, fig. 7) or rounded (Pl. 1, fig. 5). Right antapical horn less than 5 µm long, appearing as an angular bulge or a short sharp projection. A few small echinae, about 1-1.5 µm in diameter and height, are commonly present on the shoulders (Pl. 1, fig. 5), apical horn, and antapical horns especially the left and occasionally between antapical horns (Pl. 1, fig. 7). The large intercalary (2a) archeopyle is rounded hexagonal with a straight posterior margin. Operculum often still attached at posterior margin. No other indications of tabulation visible. Endoblast large and extends close to periblast laterally. Endophragm smooth to faintly scabrate and less than 1 µm thick. Endoblast sometimes has several folds (Pl. 1, fig. 6). Periphragm smooth, except for echinae described above and is about 1 µm thick. Endophragm and periphragm always distinguishable. Apical and antapical pericoels, or occasionally a single pericoel, are present. Rarely, a large opening occurs in periblast between antapical horns.
Dimensions: Holotype, 101 µm long, 62 µm wide; endoblast, 48 µm long; range, 99-122 µm long, 41-64 µm wide; endoblast, 39-54 µm long.
Now Isabelidinium. Originally Deflandrea, subsequently (and now) Isabelidinium. See also Isabelia (combination illegitimate).
Holotype: McIntyre, 1975, pl.1, figs.5,6
Locus typicus: Horton River, Northwest Territories, Canada
Stratum typicum: Campanian-Maastrichtian
Original diagnosis: McIntyre, 1975, p.65
Cyst cavate, convex in equatorial region, with approximately equal-sized epitract and hypotract. Periphragm usually folded in equatorial region, but a definite cingulum is not present. Indications of a large, wide sulcus on the ventral surface are seen occasionally. On the epitract the periblast bulges laterally above the endoblast to form small angular or sometimes rounded shoulders, on which a short, broad apical horn is situated. Apical horn usually round or blunt at the end, but occasionally has a short papilla (Pl. 1, fig. 5). Left antapical horn short, 8-12 µm long and either pointed (Pl. 1, fig. 7) or rounded (Pl. 1, fig. 5). Right antapical horn less than 5 µm long, appearing as an angular bulge or a short sharp projection. A few small echinae, about 1-1.5 µm in diameter and height, are commonly present on the shoulders (Pl. 1, fig. 5), apical horn, and antapical horns especially the left and occasionally between antapical horns (Pl. 1, fig. 7). The large intercalary (2a) archeopyle is rounded hexagonal with a straight posterior margin. Operculum often still attached at posterior margin. No other indications of tabulation visible. Endoblast large and extends close to periblast laterally. Endophragm smooth to faintly scabrate and less than 1 µm thick. Endoblast sometimes has several folds (Pl. 1, fig. 6). Periphragm smooth, except for echinae described above and is about 1 µm thick. Endophragm and periphragm always distinguishable. Apical and antapical pericoels, or occasionally a single pericoel, are present. Rarely, a large opening occurs in periblast between antapical horns.
Dimensions: Holotype, 101 µm long, 62 µm wide; endoblast, 48 µm long; range, 99-122 µm long, 41-64 µm wide; endoblast, 39-54 µm long.