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Raetiaedinium fibrostriatum
Raeiaedinium fibrostriatum Slimani, 1994, p.85–86, pl.13, figs.7–11. Holotype: Slimani, 1994, pl.13, figs.7–10. Age: late Maastrichtian.
Original description (Slimani, 1994) Not yet translated from French
Name derivation: Latin: fibra, fiber; striants, striated; referring to the fibrous central body and striated processes.
Location: Halembaye sample 48, preparation 2, coordinates E.F. K41/1.
Type locality: Halembaye sample 48.
Type horizon: Upper Maastrichtian (Vijlen Member).
Diagnosis: Chorionic cyst; the central body is subspheroidal to ovoid, fibroreticular, and bears one tubular process per plate. The processes are rigid, strongly striated, and closed distally; they are of comparable length but highly variable width. The dorsal postcingular processes are the widest and terminate distally in more or less branched ends with a more or less irregular margin bearing small spines; the other processes are all simple with an apparently dry to digitate margin. The paratabulation is of the gonyaulacoid type: 4', 6", 6c, 6", lp, 1", 5s. The archeopyl is precingular of the 2P(3'+4') type with a free, two-piece operculum.
Dimensions: Holotype: central body; length: 44 µm, width: 40 µm.
Process length: 30 µm. Variations: central body, length: 40–60 µm, width: 40–44 µm. Process length: 22–34 µm. Number of specimens measured: 14. Material: 17 specimens.
Description: The central body bears a small, rarely visible apical bump, 4 µm long. The granular to fibrous endophragm (1–2 µm thick) and the thin, fibro-reticulate periphragm are in contact between the processes. The processes have thin walls with longitudinal striations. The apical and sulcal processes are thin and slender; the dorsal postcingular processes are prominent and broad (10–20 µm wide), bifurcated or slightly branched with a subcircular basal section, and flatten toward their distal end. The dorsal precingular processes (8–14 µm wide) are slightly narrower than the postcingular processes. The antapical process, the paracingular processes, and the ventral precingular and postcingular processes are of intermediate width. The archeopyle and the small apical bump facilitate the orientation of the cyst.
Comparison: Achilleodinium arboriforme Marheinecke (1992) from the Upper Maastrichtian of Hemmoor (Germany) is represented by a cyst whose general appearance resembles that of Raetiaedinium fihrostriatum BD. nov., but it differs in its processes, which have a thicker wall, and especially in its P-type precingular archeopyle resulting from the detachment of a single precingular plate. The present species is distinguished from Raetiaedinium punctatum gp. nov. (in this work) by its larger size, its thicker and more fibrous wall, and by its more variable processes, which are larger and more strongly striated.
Locality: Halembaye: specimens 35–48, Upper Maastrichtian (B. junior zone).
Original description (Slimani, 1994) Not yet translated from French
Name derivation: Latin: fibra, fiber; striants, striated; referring to the fibrous central body and striated processes.
Location: Halembaye sample 48, preparation 2, coordinates E.F. K41/1.
Type locality: Halembaye sample 48.
Type horizon: Upper Maastrichtian (Vijlen Member).
Diagnosis: Chorionic cyst; the central body is subspheroidal to ovoid, fibroreticular, and bears one tubular process per plate. The processes are rigid, strongly striated, and closed distally; they are of comparable length but highly variable width. The dorsal postcingular processes are the widest and terminate distally in more or less branched ends with a more or less irregular margin bearing small spines; the other processes are all simple with an apparently dry to digitate margin. The paratabulation is of the gonyaulacoid type: 4', 6", 6c, 6", lp, 1", 5s. The archeopyl is precingular of the 2P(3'+4') type with a free, two-piece operculum.
Dimensions: Holotype: central body; length: 44 µm, width: 40 µm.
Process length: 30 µm. Variations: central body, length: 40–60 µm, width: 40–44 µm. Process length: 22–34 µm. Number of specimens measured: 14. Material: 17 specimens.
Description: The central body bears a small, rarely visible apical bump, 4 µm long. The granular to fibrous endophragm (1–2 µm thick) and the thin, fibro-reticulate periphragm are in contact between the processes. The processes have thin walls with longitudinal striations. The apical and sulcal processes are thin and slender; the dorsal postcingular processes are prominent and broad (10–20 µm wide), bifurcated or slightly branched with a subcircular basal section, and flatten toward their distal end. The dorsal precingular processes (8–14 µm wide) are slightly narrower than the postcingular processes. The antapical process, the paracingular processes, and the ventral precingular and postcingular processes are of intermediate width. The archeopyle and the small apical bump facilitate the orientation of the cyst.
Comparison: Achilleodinium arboriforme Marheinecke (1992) from the Upper Maastrichtian of Hemmoor (Germany) is represented by a cyst whose general appearance resembles that of Raetiaedinium fihrostriatum BD. nov., but it differs in its processes, which have a thicker wall, and especially in its P-type precingular archeopyle resulting from the detachment of a single precingular plate. The present species is distinguished from Raetiaedinium punctatum gp. nov. (in this work) by its larger size, its thicker and more fibrous wall, and by its more variable processes, which are larger and more strongly striated.
Locality: Halembaye: specimens 35–48, Upper Maastrichtian (B. junior zone).