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Scriniodinium
From Fensome et al., 2019:
Scriniodinium, Klement, 1957, p.409–410.
Emendations: Prauss, 1989, p.45; Riding and Fensome, 2002, p.9–10; Pestchevitskaya and Lebedeva, 2017, p.106.
Taxonomic junior synonyms: Endoscrinium, according to Stover and Evitt (1978, p.187), Dodekova (1990, p.30–31), and Pestchevitskaya and Lebedeva (2017, p.106) -- however, Lentin and Williams (1993, p.207) and the present authors herein retained Endoscrinium; Athigmatocysta, according to Stover and Williams (1987, p.27), Brenner (1988, p.72), and Pestchevitskaya and Lebedeva (2017, p.106) -- however, Harding (1990b, p.28) and the present authors retain Athigmatocysta. In considering Endoscrinium and Athigmatocysta to be taxonomic junior synonyms of Scriniodinium, Pestchevitskaya and Lebedeva (2017, p.106) did not provide a detailed analysis of constituent species; hence, pending such an analysis we prefer to retain the genera separately. Although the "type species", Scriniodinium crystallinum, was not validly transferred to Scriniodinium by Klement (1957), the generic name Scriniodinium was validly published, since it is based on a previously validly
published species name, Gymnodinium crystallinum.
Type: Deflandre, 1939a, pl.5, figs.1–2, as Gymnodinium crystallinum.
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Original description: [Klement, 1957]: (Translation: Stover and Evitt 1978, p. 187):
Diagnosis:
Ovoid, dorso-ventrally slightly flattened shell with a darker spherical to ovoid inner body. Spiral transverse furrow often only marginally visible. Presence of a clear tabulation and of a transverse furrow limited to certain species.
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Modified description:
Stover and Evitt 1978, p. 187:
Synopsis: cysts proximate, generally circumcavate, lenticular to subellipsoidal, with or without an apical horn and/or a medial antapical elongation; paratabulation indicated by archeopyle and paracingulum, additionally by low parasutural ridges on some forms; archeopyle precingular, Type P.
Description:
Shape: Lenticular, subspherical or subellipsoidal; outline subcircular to roundly kiteshaped; apical horn and/or antapical elongation may be present.
Wall relationships: Cysts typically circumcavate; occasionally endophragm and periphragm are in contact locally along lateral margins.
Wall features: Parasutural features absent or consisting of low narrow ridges or linear markings on the periphragm. Otherwise, endophragm and periphragm smooth, or faintly to clearly ornamented with features of low relief.
Paratabulation: Indicated partially, by archeopyle and paracingulum, to completely, by parasutural features; gonyaulacacean, formula: 3-4`, 6``, Xc, 5-6```, 0-1p, 0-1````.
Archeopyle: Precingular, Type P (3`` only); operculum free.
Paracingulum: Indicated by parallel transverse parasutural ridges, a shallow depression, or interruptions along the lateral margins about midlength. Parasulcus: Generally not indicated, or expressed as a faint depression mainly on the hypocyst.
Size: Intermediate to large.
Affinities:
Scriniodinium differs from Tubotuberella in being less elongate longitudinally and in lacking the relatively long subcylindrical to subrectangular antapical elongation with a large porelike opening as is found in Tubotuberella.
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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.
Scriniodinium Klement, 1957, emend. Prauss, 1989. Scriniodinium was emended by Prauss (1989), who gave the tabulation as cop, pop, cap, POR, 4`, 0-2a, 6", xc, 6"' , 0-1p, 1"" , Nrs. This is confusing since the generally held concept of Scriniodinium is that it differs from Endoscrinium in not showing tabulation. This is a circumcavate cyst with a precingular archeopyle resulting from the loss of 3".
Scriniodinium, Klement, 1957, p.409–410.
Emendations: Prauss, 1989, p.45; Riding and Fensome, 2002, p.9–10; Pestchevitskaya and Lebedeva, 2017, p.106.
Taxonomic junior synonyms: Endoscrinium, according to Stover and Evitt (1978, p.187), Dodekova (1990, p.30–31), and Pestchevitskaya and Lebedeva (2017, p.106) -- however, Lentin and Williams (1993, p.207) and the present authors herein retained Endoscrinium; Athigmatocysta, according to Stover and Williams (1987, p.27), Brenner (1988, p.72), and Pestchevitskaya and Lebedeva (2017, p.106) -- however, Harding (1990b, p.28) and the present authors retain Athigmatocysta. In considering Endoscrinium and Athigmatocysta to be taxonomic junior synonyms of Scriniodinium, Pestchevitskaya and Lebedeva (2017, p.106) did not provide a detailed analysis of constituent species; hence, pending such an analysis we prefer to retain the genera separately. Although the "type species", Scriniodinium crystallinum, was not validly transferred to Scriniodinium by Klement (1957), the generic name Scriniodinium was validly published, since it is based on a previously validly
published species name, Gymnodinium crystallinum.
Type: Deflandre, 1939a, pl.5, figs.1–2, as Gymnodinium crystallinum.
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Klement, 1957]: (Translation: Stover and Evitt 1978, p. 187):
Diagnosis:
Ovoid, dorso-ventrally slightly flattened shell with a darker spherical to ovoid inner body. Spiral transverse furrow often only marginally visible. Presence of a clear tabulation and of a transverse furrow limited to certain species.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Modified description:
Stover and Evitt 1978, p. 187:
Synopsis: cysts proximate, generally circumcavate, lenticular to subellipsoidal, with or without an apical horn and/or a medial antapical elongation; paratabulation indicated by archeopyle and paracingulum, additionally by low parasutural ridges on some forms; archeopyle precingular, Type P.
Description:
Shape: Lenticular, subspherical or subellipsoidal; outline subcircular to roundly kiteshaped; apical horn and/or antapical elongation may be present.
Wall relationships: Cysts typically circumcavate; occasionally endophragm and periphragm are in contact locally along lateral margins.
Wall features: Parasutural features absent or consisting of low narrow ridges or linear markings on the periphragm. Otherwise, endophragm and periphragm smooth, or faintly to clearly ornamented with features of low relief.
Paratabulation: Indicated partially, by archeopyle and paracingulum, to completely, by parasutural features; gonyaulacacean, formula: 3-4`, 6``, Xc, 5-6```, 0-1p, 0-1````.
Archeopyle: Precingular, Type P (3`` only); operculum free.
Paracingulum: Indicated by parallel transverse parasutural ridges, a shallow depression, or interruptions along the lateral margins about midlength. Parasulcus: Generally not indicated, or expressed as a faint depression mainly on the hypocyst.
Size: Intermediate to large.
Affinities:
Scriniodinium differs from Tubotuberella in being less elongate longitudinally and in lacking the relatively long subcylindrical to subrectangular antapical elongation with a large porelike opening as is found in Tubotuberella.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Scriniodinium Klement, 1957, emend. Prauss, 1989. Scriniodinium was emended by Prauss (1989), who gave the tabulation as cop, pop, cap, POR, 4`, 0-2a, 6", xc, 6"' , 0-1p, 1"" , Nrs. This is confusing since the generally held concept of Scriniodinium is that it differs from Endoscrinium in not showing tabulation. This is a circumcavate cyst with a precingular archeopyle resulting from the loss of 3".