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Rhynchodiniopsis cauda
Rhynchidiniopsis "cauda" (Gitmez and Sarjeant, 1972, p.193–194, pl.2, figs.1–2,4–5) Sarjeant, 1982b, p.35. Holotype: Gitmez and Sarjeant, 1972, pl.2, figs.1–2. Originally Gonyaulacysta, subsequently Millioudodinium, thirdly Rhynchodiniopsis, fourthly Cribroperidinium?. Taxonomic senior synonym: Gonyaulacysta globata, according to Poulsen (1996, p.72). N.I.A. Age: early–late Kimmeridgian.
Original diagnosis: Gitmez and Sarjeant, 1972, p.193: Gonyaulacysta cauda
The broadly ovoidal cyst possesses a poorly developed apical horn with long spines arising from its tip. Tabulation: 4", 1a, 6", 6c, 6""", 1p, 1pV and 1"""". Spiny crests separate the plates. The single antapical plate is characteristically surrounded by long (nearly three times longer than the other sutural spines), thin, simple spines. Cingulum helicoid, laevorotatory; sulcus moderately broad, extending on both epitract and hypotract to the same length. Surface densely granular. Precingular archaeopyle, if present, formed by loss of plate 3".
Dimensions: Holotype: overall length 78 µm, breadth 50 µm, apical horn length 8 µm; length of the sutural processes 3-5 µm, antapical processes 8 µm; breadth of the cingulum 3.5 µm. Paratype: length 80 µm, breadth 65 µm, apical horn length 12 µm, antapical processes length 10 µm.
Original description: Gitmez and Sarjeant, 1972, p.193-194: Gonyaulacysta cauda
The slightly helicoid, laevorotatory cingulum of moderate breadth, divides the cyst into two unequal parts. The conical epitract terminates in a poorly developed apical horn, the hypotract is dome-shaped. The epitract is larger than the hypotract, almost two-thirds of the shell length. Apical plate 1" is elongate, its anterior and posterior ends being narrow; together with plate 3", it forms the apical horn. Plate 2" is quite large; 4" is the smallest of the apical plates. The single anterior intercalary plate 1a is large; as a result plate 6"" is reduced. The precingular plate 1" is long and narrow; plates 2"", 3"", 4"" and 5"" are large. One of the specimens observed has a precingular archaeopyle, formed by loss of plate 3"". Six postcingular plates occupy the hypotract, together with the single antapical plate and the posterior plates. Plate 1""" is quadrate and as small as the adjacent sulcal plate; all the other postcingular plates are relatively large. A crescent-shaped plate, 1pv, separates the sulcus from antapical plate 1"""". The boundary surrounding the antapical plate 1"""" bears longer spines than the other sutural spines. All the sutural spines are simple, solid, thin, threadlike.
Original diagnosis: Gitmez and Sarjeant, 1972, p.193: Gonyaulacysta cauda
The broadly ovoidal cyst possesses a poorly developed apical horn with long spines arising from its tip. Tabulation: 4", 1a, 6", 6c, 6""", 1p, 1pV and 1"""". Spiny crests separate the plates. The single antapical plate is characteristically surrounded by long (nearly three times longer than the other sutural spines), thin, simple spines. Cingulum helicoid, laevorotatory; sulcus moderately broad, extending on both epitract and hypotract to the same length. Surface densely granular. Precingular archaeopyle, if present, formed by loss of plate 3".
Dimensions: Holotype: overall length 78 µm, breadth 50 µm, apical horn length 8 µm; length of the sutural processes 3-5 µm, antapical processes 8 µm; breadth of the cingulum 3.5 µm. Paratype: length 80 µm, breadth 65 µm, apical horn length 12 µm, antapical processes length 10 µm.
Original description: Gitmez and Sarjeant, 1972, p.193-194: Gonyaulacysta cauda
The slightly helicoid, laevorotatory cingulum of moderate breadth, divides the cyst into two unequal parts. The conical epitract terminates in a poorly developed apical horn, the hypotract is dome-shaped. The epitract is larger than the hypotract, almost two-thirds of the shell length. Apical plate 1" is elongate, its anterior and posterior ends being narrow; together with plate 3", it forms the apical horn. Plate 2" is quite large; 4" is the smallest of the apical plates. The single anterior intercalary plate 1a is large; as a result plate 6"" is reduced. The precingular plate 1" is long and narrow; plates 2"", 3"", 4"" and 5"" are large. One of the specimens observed has a precingular archaeopyle, formed by loss of plate 3"". Six postcingular plates occupy the hypotract, together with the single antapical plate and the posterior plates. Plate 1""" is quadrate and as small as the adjacent sulcal plate; all the other postcingular plates are relatively large. A crescent-shaped plate, 1pv, separates the sulcus from antapical plate 1"""". The boundary surrounding the antapical plate 1"""" bears longer spines than the other sutural spines. All the sutural spines are simple, solid, thin, threadlike.