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Korystocysta
From Williams et al., 2017:
[Korystocysta, Woollam, 1983, p. 193–194; Emendation: Benson, 1985, p. 154
Tax. sr. syn.: Ctenidodinium, according to Courtinat (1989, p.208) — however, Lentin and Williams (1989, p.213) retained Korystocysta.
Type species: originally as Dichadogonyaulax kettonensis, Sarjeant, 1976a (pl.1, figs.1–2)] ; Korystocysta kettonensis, Woollam, 1983
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Original description: [Woollam, 1983]:
Diagnosis:
Cysts proximate, autophragm only or two wall layers closely appressed. Body ellipsoidal generally with a short apical horn.
Paratabulation gonyaulacoid, 0-3pa, 4`, 0-2a, 6``, 6c, x-6s, 6```, 1 p, 1````, indicated by uniformly developed low denticulate parasutural crests. Low denticulate intratabular crests variably present. 1p characteristically very elongate.
Archaeopyle epicystal, formed by schism along a line anterior to the paracingulum, initiated dorsally, operculum (epicyst) attached ventrally at the parasulcus.
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Emended description:
Benson, 1985:
Diagnosis:
Proximate dinocysts constructed of an autophragm. Subspherical to ellipsoidal in shape generally bearing an abbreviate apical horn.
Paratabulation formula: 1-3pr, 4`, 1-2a, x-6c, 6```, 1p, 1````, x-6s, indicated by parasutural ridges, which may or may not be ornamented with short spines or denticles. Accessory ridges ("growth bands") invariably present, expressed as denticulate or non-denticulate ridges. Combination (epicystal, type E) archaeopyle separating along the posterior margin of the precingular paraplates. Operculum free or attached at parasulcus.
Note:
(Stover and Williams, 1987, p. 136): In the emended diagnosis, the symbol for and the number of paraplates in the precingular series were inadvertently omitted from the formula; 6", should be inserted after 1-2a.
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Modified description:
Stover and Williams, 1987, p. 135:
Synopsis: Cysts proximate, subspherical, generally with an apical horn; paratabulation basically gonyaulacacean, indicated by low, parasutural ridges; growth ridges present; archaeopyle epicystal, type E of Benson (1985); opercular piece free or adnate.
Description:
Shape: Body subspherical.
Wall relationships: Autophragm only.
Wall features: Parasutural ridges low; may be ornamented with short spines or denticles; growth ridges present in intratabular areas.
Archaeopyle: Epicystal, type E of Benson (1985), = [tpr tA ta tP], principal archaeopyle suture along or near posterior margin of precingular plates and anterior to the paracingulum. Single opercular piece free or adnate.
Paratabulation: Indicated by parasutural features, basically gonyaulacacean with preapical and anterior intercalary paraplates; formula: 1-3pr, 4`, 1-2a, 6``, x-6c, 6```, 1p, 1````, x-6s. Apical paraplates 2` and 4` separated by preapicals.
Paracingulum: Indicated by similarly developed, transverse equatorial ridges; area between ridges may be divided longitudinally.
Parasulcus: Variously developed on hypocyst; may be subdivided.
Size: Intermediate; about 50 to 90 µm in equatorial diameter.
Affinities:
According to Woollam (1983, p. 194) Korystocysta differs from Ctenidodinium Deflandre 1938 emend. Woollam 1983 and from Bradleyella Woollam 1983 in . . ."the presence of an apical horn and in details of ventral paratabulation, particularly in the marked elongation of 1p".
Benson (1985, p. 147) used the presence of growth ridges and an apical horn as criteria for separating Korystocysta Woollam 1983 emend. Benson 1985 from Ctenidodinium Deflandre 1938 emend. Benson 1985 and from Dichadogonyaulax Sarjeant in Davey et al. 1966 emend. Benson 1985. Additional features for distinguishing Korystocysta from Dichadogonyaulax are, following Benson`s emendations, the presence of anterior intercalary paraplates together with the separation of paraplates 2` and 4` by preapical paraplates in the former genus.
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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Korystocysta Woollam, 1983, emend. Benson, 1985. Benson (1985, p.154) stated that this species is proximate, with autophragm only. Body ellipsoidal, generally with apical horn. Tabulation: 1-3pa, 4`, 1-2a, 6", x-6c, 6"', 1p, 1"'', x-6s, indicated by parasutural ridges, which may or may not be ornamented with short spines or denticles. Accessory ridges (''growth bands'') invariably present, expressed as denticulate or non-denticulate ridges. Combination (epicystal type E) archeopyle separating along the posterior margin of the precingular paraplates. Operculum free or attached at parasulcus. According to Benson, this genus differs from Ctenidodinium and Dichadogonyaulax in the presence of an apical horn and growth ridges. There is also the presence of anterior intercalary plates and the separation of 2` and 4` by preapicals.
[Korystocysta, Woollam, 1983, p. 193–194; Emendation: Benson, 1985, p. 154
Tax. sr. syn.: Ctenidodinium, according to Courtinat (1989, p.208) — however, Lentin and Williams (1989, p.213) retained Korystocysta.
Type species: originally as Dichadogonyaulax kettonensis, Sarjeant, 1976a (pl.1, figs.1–2)] ; Korystocysta kettonensis, Woollam, 1983
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Woollam, 1983]:
Diagnosis:
Cysts proximate, autophragm only or two wall layers closely appressed. Body ellipsoidal generally with a short apical horn.
Paratabulation gonyaulacoid, 0-3pa, 4`, 0-2a, 6``, 6c, x-6s, 6```, 1 p, 1````, indicated by uniformly developed low denticulate parasutural crests. Low denticulate intratabular crests variably present. 1p characteristically very elongate.
Archaeopyle epicystal, formed by schism along a line anterior to the paracingulum, initiated dorsally, operculum (epicyst) attached ventrally at the parasulcus.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended description:
Benson, 1985:
Diagnosis:
Proximate dinocysts constructed of an autophragm. Subspherical to ellipsoidal in shape generally bearing an abbreviate apical horn.
Paratabulation formula: 1-3pr, 4`, 1-2a, x-6c, 6```, 1p, 1````, x-6s, indicated by parasutural ridges, which may or may not be ornamented with short spines or denticles. Accessory ridges ("growth bands") invariably present, expressed as denticulate or non-denticulate ridges. Combination (epicystal, type E) archaeopyle separating along the posterior margin of the precingular paraplates. Operculum free or attached at parasulcus.
Note:
(Stover and Williams, 1987, p. 136): In the emended diagnosis, the symbol for and the number of paraplates in the precingular series were inadvertently omitted from the formula; 6", should be inserted after 1-2a.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Modified description:
Stover and Williams, 1987, p. 135:
Synopsis: Cysts proximate, subspherical, generally with an apical horn; paratabulation basically gonyaulacacean, indicated by low, parasutural ridges; growth ridges present; archaeopyle epicystal, type E of Benson (1985); opercular piece free or adnate.
Description:
Shape: Body subspherical.
Wall relationships: Autophragm only.
Wall features: Parasutural ridges low; may be ornamented with short spines or denticles; growth ridges present in intratabular areas.
Archaeopyle: Epicystal, type E of Benson (1985), = [tpr tA ta tP], principal archaeopyle suture along or near posterior margin of precingular plates and anterior to the paracingulum. Single opercular piece free or adnate.
Paratabulation: Indicated by parasutural features, basically gonyaulacacean with preapical and anterior intercalary paraplates; formula: 1-3pr, 4`, 1-2a, 6``, x-6c, 6```, 1p, 1````, x-6s. Apical paraplates 2` and 4` separated by preapicals.
Paracingulum: Indicated by similarly developed, transverse equatorial ridges; area between ridges may be divided longitudinally.
Parasulcus: Variously developed on hypocyst; may be subdivided.
Size: Intermediate; about 50 to 90 µm in equatorial diameter.
Affinities:
According to Woollam (1983, p. 194) Korystocysta differs from Ctenidodinium Deflandre 1938 emend. Woollam 1983 and from Bradleyella Woollam 1983 in . . ."the presence of an apical horn and in details of ventral paratabulation, particularly in the marked elongation of 1p".
Benson (1985, p. 147) used the presence of growth ridges and an apical horn as criteria for separating Korystocysta Woollam 1983 emend. Benson 1985 from Ctenidodinium Deflandre 1938 emend. Benson 1985 and from Dichadogonyaulax Sarjeant in Davey et al. 1966 emend. Benson 1985. Additional features for distinguishing Korystocysta from Dichadogonyaulax are, following Benson`s emendations, the presence of anterior intercalary paraplates together with the separation of paraplates 2` and 4` by preapical paraplates in the former genus.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Korystocysta Woollam, 1983, emend. Benson, 1985. Benson (1985, p.154) stated that this species is proximate, with autophragm only. Body ellipsoidal, generally with apical horn. Tabulation: 1-3pa, 4`, 1-2a, 6", x-6c, 6"', 1p, 1"'', x-6s, indicated by parasutural ridges, which may or may not be ornamented with short spines or denticles. Accessory ridges (''growth bands'') invariably present, expressed as denticulate or non-denticulate ridges. Combination (epicystal type E) archeopyle separating along the posterior margin of the precingular paraplates. Operculum free or attached at parasulcus. According to Benson, this genus differs from Ctenidodinium and Dichadogonyaulax in the presence of an apical horn and growth ridges. There is also the presence of anterior intercalary plates and the separation of 2` and 4` by preapicals.