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Gonyaulacysta piriformis
From Fensome et al., 2019:
Gonyaulacysta piriformis Conrad, 1941, p.9, pl.1, fig.G ex Sarjeant, 1967b, p.255. Holotype: Conrad, 1941, pl.1, fig.G. Originally Palaeoperidinium (name not validly published), subsequently Gonyaulacysta?, thirdly (and now) Gonyaulacysta, fourthly Palaeoperidinium? (combination not validly published). Questionable assignment: Sarjeant (1967b, p.255)— however, Lentin and Williams (1976, p.111) included this species in Gonyaulacysta without question. The name Palaeoperidinium piriforme was not validly published in Conrad (1941) since the generic name Palaeoperidinium was not validly published until 1967. Williams et al. (1998, p.255) accepted Sarjeant's (1967b) indirect reference to Conrad (1941) as indication of a type (ICN Article 40.3). Lentin and Williams (1976, p.111) also proposed this name as a "comb. nov.". Jan du Chêne et al. (1986a, p.132) recommended that this name be restricted to the holotype. Age: Maastrichtian.
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Original description (Conrad, 1941) (translated from French):
P. piriforme, n. sp. Pl. I, fig. G.
The cell is inversely pirifornous. It reaches its maximum width about one-third from the apex; from there, it gradually narrows downward and finally extends into a short caudal portion. The axis that contains the apex of the theca, the center, and the tip of the tail is an arcuate line, so that the cell is somewhat asymmetrical. The apical portion constitutes an angular cap. The apex is formed by the meeting, at a very sharp obtuse angle, of the plates that constitute this region, which we assume to be the epitheca. The transverse groove, which separates it from the hypotheca, is narrow, shallow, and difficult to discern.
The entire body is covered with pointed nipples, a kind of wide, short, blunt, very dark teeth, which makes observation very difficult. These teeth are missing from a wide longitudinal band extending from the transverse groove to the back of the body. This band is clear and regularly bordered. We consider it to be a particularly well-developed longitudinal groove. It comprises two rows of three unequal plates each. The upper two are rhombohedral or hexagonal; the others, much narrower, are more or less rectangular. Halfway up, these two rows of plates are separated by a small intercalary lozenge-shaped plate.
Length of the groove: 27 μm; width (maximum): 18 μm.
Preparation A. III.
Gonyaulacysta piriformis Conrad, 1941, p.9, pl.1, fig.G ex Sarjeant, 1967b, p.255. Holotype: Conrad, 1941, pl.1, fig.G. Originally Palaeoperidinium (name not validly published), subsequently Gonyaulacysta?, thirdly (and now) Gonyaulacysta, fourthly Palaeoperidinium? (combination not validly published). Questionable assignment: Sarjeant (1967b, p.255)— however, Lentin and Williams (1976, p.111) included this species in Gonyaulacysta without question. The name Palaeoperidinium piriforme was not validly published in Conrad (1941) since the generic name Palaeoperidinium was not validly published until 1967. Williams et al. (1998, p.255) accepted Sarjeant's (1967b) indirect reference to Conrad (1941) as indication of a type (ICN Article 40.3). Lentin and Williams (1976, p.111) also proposed this name as a "comb. nov.". Jan du Chêne et al. (1986a, p.132) recommended that this name be restricted to the holotype. Age: Maastrichtian.
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Original description (Conrad, 1941) (translated from French):
P. piriforme, n. sp. Pl. I, fig. G.
The cell is inversely pirifornous. It reaches its maximum width about one-third from the apex; from there, it gradually narrows downward and finally extends into a short caudal portion. The axis that contains the apex of the theca, the center, and the tip of the tail is an arcuate line, so that the cell is somewhat asymmetrical. The apical portion constitutes an angular cap. The apex is formed by the meeting, at a very sharp obtuse angle, of the plates that constitute this region, which we assume to be the epitheca. The transverse groove, which separates it from the hypotheca, is narrow, shallow, and difficult to discern.
The entire body is covered with pointed nipples, a kind of wide, short, blunt, very dark teeth, which makes observation very difficult. These teeth are missing from a wide longitudinal band extending from the transverse groove to the back of the body. This band is clear and regularly bordered. We consider it to be a particularly well-developed longitudinal groove. It comprises two rows of three unequal plates each. The upper two are rhombohedral or hexagonal; the others, much narrower, are more or less rectangular. Halfway up, these two rows of plates are separated by a small intercalary lozenge-shaped plate.
Length of the groove: 27 μm; width (maximum): 18 μm.
Preparation A. III.