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Chatangiella decorosa
Chatangiella decorosa, (McIntrye, 1975), Lentin and Williams, 1976
Tax. sr. synonym of Deflandrea ditissima McIntyre, 1975, according to Harker and Sarjeant in Harker et al., 1990. Harker and Sarjeant in Harker et al., 1990, retained Chatangiella ditissima as a separate species.
Holotype: McIntyre, 1975, pl.2, fig.1
Locus typicus: Horton River, Northwest Territories, Canada
Stratum typicum: Campanian-Maastrichtian
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Original description as Deflandrea decorosa: [McIntyre, 1975, p. 63]:
Diagnosis:
Cyst cavate, dorsoventrally flattened, protruding in equatorial region, and divided into equal epi- and hypotracts by a slightly laevorotatory cingulum. Rounded shoulders of varying degrees of development occur on the epitract, where the periblast bulges above the level of the endoblast. A blunt-ended, broad based apical horn 15-30 µm long is produced from the shoulders. Some specimens taper almost directly from the cingulum to the apex. A sharply pointed left antapical horn up to 40 µm long is always present and the right antapical horn appears as a rounded to angular bulge. Cingulum about 7 µm wide and bordered on anterior and posterior margins by discontinuous ridges consisting of rows of pustules, which may join to form narrow grooves (Pl. 2, fig. 2). Epitractal side of cingulum has 7 pieces of ridge and hypotractal side has 5 pieces. These apparently represent the pre- and post-cingular reflected plates, and the pieces differ in length, depending on the reflected plate represented. A group of pustules, sometimes in the form of an arc (Pl. 2, fig. 2), usually appears on the periblast adjacent to each cingulum ridge piece and probably represent intratabular ornament. Pustules are commonly present on other parts of the periblast (Pl. 2, fig. 3), but no definite pattern can be seen and some specimens have very few pustules (Pl. 2, fig. 2). Rows of small pustules or granules that indicate the apical reflected plates are sometimes present on the apical horn. A large, wide sulcus is present on the ventral surface.
The large intercalary (2a) archeopyle is rounded hexagonal (Pl. 2, fig. 3) to broadly rounded hexagonal (Pl. 2, fig. 2). Occasionally anterior margin significantly longer than posterior margin (Pl. 2, fig. 4). Operculum usually attached at posterior margin (Pl. 2, fig. 1, 3, 4). Endoblast also has indications of an archeopyle (Pl. 2, fig. 3).
The tabulation pattern is probably of the typical fossil peridinioid type 4" 3a 7" 5""" 2"""".
Endoblast large with smooth endophragm about 1/2 µm thick. Periphragm less than 1 µm thick and ornamented with pustules described above. Otherwise it is smooth (Pl. 2, fig. 2) to faintly scabrate (Pl. 2, fig. 3) and appears to have a faint LO pattern. The endoblast is somewhat folded at its anterior and posterior ends, well rounded and normally separated laterally from the periblast except in the postcingular plate area, where the endophragm and periphragm usually appear to be fused into one layer. Large apical and antapical pericoels are present.
Dimensions:
Holotype, 156 µm long, 96 µm wide; endoblast, 73 µm long; range, 130-175 µm long, 80-110 µm wide; endoblast, 85-110 µm long.
Tax. sr. synonym of Deflandrea ditissima McIntyre, 1975, according to Harker and Sarjeant in Harker et al., 1990. Harker and Sarjeant in Harker et al., 1990, retained Chatangiella ditissima as a separate species.
Holotype: McIntyre, 1975, pl.2, fig.1
Locus typicus: Horton River, Northwest Territories, Canada
Stratum typicum: Campanian-Maastrichtian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description as Deflandrea decorosa: [McIntyre, 1975, p. 63]:
Diagnosis:
Cyst cavate, dorsoventrally flattened, protruding in equatorial region, and divided into equal epi- and hypotracts by a slightly laevorotatory cingulum. Rounded shoulders of varying degrees of development occur on the epitract, where the periblast bulges above the level of the endoblast. A blunt-ended, broad based apical horn 15-30 µm long is produced from the shoulders. Some specimens taper almost directly from the cingulum to the apex. A sharply pointed left antapical horn up to 40 µm long is always present and the right antapical horn appears as a rounded to angular bulge. Cingulum about 7 µm wide and bordered on anterior and posterior margins by discontinuous ridges consisting of rows of pustules, which may join to form narrow grooves (Pl. 2, fig. 2). Epitractal side of cingulum has 7 pieces of ridge and hypotractal side has 5 pieces. These apparently represent the pre- and post-cingular reflected plates, and the pieces differ in length, depending on the reflected plate represented. A group of pustules, sometimes in the form of an arc (Pl. 2, fig. 2), usually appears on the periblast adjacent to each cingulum ridge piece and probably represent intratabular ornament. Pustules are commonly present on other parts of the periblast (Pl. 2, fig. 3), but no definite pattern can be seen and some specimens have very few pustules (Pl. 2, fig. 2). Rows of small pustules or granules that indicate the apical reflected plates are sometimes present on the apical horn. A large, wide sulcus is present on the ventral surface.
The large intercalary (2a) archeopyle is rounded hexagonal (Pl. 2, fig. 3) to broadly rounded hexagonal (Pl. 2, fig. 2). Occasionally anterior margin significantly longer than posterior margin (Pl. 2, fig. 4). Operculum usually attached at posterior margin (Pl. 2, fig. 1, 3, 4). Endoblast also has indications of an archeopyle (Pl. 2, fig. 3).
The tabulation pattern is probably of the typical fossil peridinioid type 4" 3a 7" 5""" 2"""".
Endoblast large with smooth endophragm about 1/2 µm thick. Periphragm less than 1 µm thick and ornamented with pustules described above. Otherwise it is smooth (Pl. 2, fig. 2) to faintly scabrate (Pl. 2, fig. 3) and appears to have a faint LO pattern. The endoblast is somewhat folded at its anterior and posterior ends, well rounded and normally separated laterally from the periblast except in the postcingular plate area, where the endophragm and periphragm usually appear to be fused into one layer. Large apical and antapical pericoels are present.
Dimensions:
Holotype, 156 µm long, 96 µm wide; endoblast, 73 µm long; range, 130-175 µm long, 80-110 µm wide; endoblast, 85-110 µm long.