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Chichaouadinium
From Williams et al., 2017:
[Chichaouadinium, Below, 1981a, p. 122-123
Type species: Chichaouadinium arabicum, Below, 1981a (pl.10, figs.13a–c; text-fig.81h)]
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Original description: [Below, 1981]: ( Translation: Stover and Williams, 1987, p. 60):
Diagnosis:
Cysts comucavate to bicavate. Pericyst ovoidal, rhomboidal pentagonal or fusiform. Periepicyst with a bluntly pointed apex, or with a short apical horn. Perihypocyst with a rounded antapex and two symmetrically-situated antapical horns, whose lengths are often unequal and the right one can be reduced completely. The endocyst completely fills the pericyst with the exception of small apical and antapical pericoels. The shape of the inner body, therefore, is impressed on the pericyst. Spheroidal, longitudinally to transversely ovoidal endocysts are in contact with the outer body only circumcingularly, so that two, large, polar pericoels occur between the two membranes.
The endophragm is smooth, whereas the periphragm has intratabular or penitabular ornamentation of diverse shape.
Pandasutural bands or the penitabular arrangement of the ornamentation makes it possible to determine the peridinioid paratabulation of the pericyst as 4`, 3a, 7``, 5```, 2``` with a `standard hexa-fomm` 2a paraplate. Endocyst without recognizable paratabulation. Para-pericingulum wide, depressed in the pericyst, with or without ornamentation, planar or weakly spiral.
Parasulcus clearly developed or masked by ornamentation.
Archeopyle of the cornucavate cysts Ia(2a) + 3Pa(3``-5``) or I(2a) + 3Pa(3``-5``) or ?I(2a)+ 3Pa(3``-5``) with a single-walled operculum for the peri- and endocyst. The periarcheopyle corresponds to that of [other] bicavate forms. Endoarcheopyle of bicavate forms unknown.
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Modified description:
Stover and Williams, 1987, p. 59:
Synopsis: Cysts proximate, bicavate to cornucavate, outline in dorsal-ventral view roundly peridinioid with a short apical horn and one or two unequal antapical horns; paratabulation expressed mainly by penitabular and/or intratabular features and may be accentuated by pandasutural bands, peridiniacean, hexastyle, formula: 4`, 3a, 7", Xc, 5```, 2````; combined intercalary and precingular archeopyle; type l@ + 3P@, or I + 3P@, or ?l + 3P.
Description:
Shape: Pericyst outline in dorsal ventral view peridinioid to roundly triangular, with a relatively short apical horn and one or two antapical horns; right antapical horn commonly reduced.
Wall relationships: Cysts bicavate to cornucavate with a spheroidal endocyst.
Wall features: Periphragm ornamented with features of low relief arranged in penitabular rows (frequently discontinuous) or intratabular clusters, or combination thereof; pandasutural bands may be present; endophragm apparently smooth. Accessory archeopyle sutures between precingular paraplates of variable length.
Archeopyle: Combined intercalary and precingular, type I + 3P@, with the 2a paraplate free or attached to paraplate 4"; the original description allows for a type ?l + 3P archeopyle, but no examples are given.
Paratabulation: Expressed mainly by penitabular and/or intratabular features, and may be emphasized by pandasutural bands; peridiniacean, formula: 4`, 3a, 7", Xc, 5```, 2````; 2a linteloid.
Paracingulum: Usually indicated by a shallow, transverse, equatorial (or nearly so) depression that may be bounded by low ridges; typically undivided longitudinally.
Parasulcus: Indicated by shallow, longitudinal depression on hypocyst; may be obscured by ornamentation.
Size: Small to intermediate, about 35 to 90 µm.
Affinities:
Differences in archeopyle types are the principal means for separating similarly shaped, cavate, peridiniacean genera from Chichaouadinium. In Ginginodinium Cookson and Eisenack 1960 emended Lentin and Williams 1976, the three intercalary paraplates (1 a-3a) are consistently involved in archeopyle formation, whereas the subjacent precingular paraplates (3"-5") are rarely involved. Williamsidinium Lentin 1983 has a 3[1P]@ in which no paraplates are freed from the cyst. Each intercalary paraplate remains attached to its subjacent precingular paraplate, which, in turn, is adnate adcingularly. Spinidinium Cookson and Eisenack 1962b emended Lentin and Williams 1976 has a simple 1(2a) archeopyle, as does Vozzhennikovia Lentin and Williams 1976, which also has nontabular ornamentation.
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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.
Chichaouadinium Below, 1981a, has a peridinioid outline with a short apical and two unequally developed antapical horns. The 2a plate is steno-deltaform. The archeopyle is Ia + 3Pa or I + 3Pa.
[Chichaouadinium, Below, 1981a, p. 122-123
Type species: Chichaouadinium arabicum, Below, 1981a (pl.10, figs.13a–c; text-fig.81h)]
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Original description: [Below, 1981]: ( Translation: Stover and Williams, 1987, p. 60):
Diagnosis:
Cysts comucavate to bicavate. Pericyst ovoidal, rhomboidal pentagonal or fusiform. Periepicyst with a bluntly pointed apex, or with a short apical horn. Perihypocyst with a rounded antapex and two symmetrically-situated antapical horns, whose lengths are often unequal and the right one can be reduced completely. The endocyst completely fills the pericyst with the exception of small apical and antapical pericoels. The shape of the inner body, therefore, is impressed on the pericyst. Spheroidal, longitudinally to transversely ovoidal endocysts are in contact with the outer body only circumcingularly, so that two, large, polar pericoels occur between the two membranes.
The endophragm is smooth, whereas the periphragm has intratabular or penitabular ornamentation of diverse shape.
Pandasutural bands or the penitabular arrangement of the ornamentation makes it possible to determine the peridinioid paratabulation of the pericyst as 4`, 3a, 7``, 5```, 2``` with a `standard hexa-fomm` 2a paraplate. Endocyst without recognizable paratabulation. Para-pericingulum wide, depressed in the pericyst, with or without ornamentation, planar or weakly spiral.
Parasulcus clearly developed or masked by ornamentation.
Archeopyle of the cornucavate cysts Ia(2a) + 3Pa(3``-5``) or I(2a) + 3Pa(3``-5``) or ?I(2a)+ 3Pa(3``-5``) with a single-walled operculum for the peri- and endocyst. The periarcheopyle corresponds to that of [other] bicavate forms. Endoarcheopyle of bicavate forms unknown.
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Modified description:
Stover and Williams, 1987, p. 59:
Synopsis: Cysts proximate, bicavate to cornucavate, outline in dorsal-ventral view roundly peridinioid with a short apical horn and one or two unequal antapical horns; paratabulation expressed mainly by penitabular and/or intratabular features and may be accentuated by pandasutural bands, peridiniacean, hexastyle, formula: 4`, 3a, 7", Xc, 5```, 2````; combined intercalary and precingular archeopyle; type l@ + 3P@, or I + 3P@, or ?l + 3P.
Description:
Shape: Pericyst outline in dorsal ventral view peridinioid to roundly triangular, with a relatively short apical horn and one or two antapical horns; right antapical horn commonly reduced.
Wall relationships: Cysts bicavate to cornucavate with a spheroidal endocyst.
Wall features: Periphragm ornamented with features of low relief arranged in penitabular rows (frequently discontinuous) or intratabular clusters, or combination thereof; pandasutural bands may be present; endophragm apparently smooth. Accessory archeopyle sutures between precingular paraplates of variable length.
Archeopyle: Combined intercalary and precingular, type I + 3P@, with the 2a paraplate free or attached to paraplate 4"; the original description allows for a type ?l + 3P archeopyle, but no examples are given.
Paratabulation: Expressed mainly by penitabular and/or intratabular features, and may be emphasized by pandasutural bands; peridiniacean, formula: 4`, 3a, 7", Xc, 5```, 2````; 2a linteloid.
Paracingulum: Usually indicated by a shallow, transverse, equatorial (or nearly so) depression that may be bounded by low ridges; typically undivided longitudinally.
Parasulcus: Indicated by shallow, longitudinal depression on hypocyst; may be obscured by ornamentation.
Size: Small to intermediate, about 35 to 90 µm.
Affinities:
Differences in archeopyle types are the principal means for separating similarly shaped, cavate, peridiniacean genera from Chichaouadinium. In Ginginodinium Cookson and Eisenack 1960 emended Lentin and Williams 1976, the three intercalary paraplates (1 a-3a) are consistently involved in archeopyle formation, whereas the subjacent precingular paraplates (3"-5") are rarely involved. Williamsidinium Lentin 1983 has a 3[1P]@ in which no paraplates are freed from the cyst. Each intercalary paraplate remains attached to its subjacent precingular paraplate, which, in turn, is adnate adcingularly. Spinidinium Cookson and Eisenack 1962b emended Lentin and Williams 1976 has a simple 1(2a) archeopyle, as does Vozzhennikovia Lentin and Williams 1976, which also has nontabular ornamentation.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Chichaouadinium Below, 1981a, has a peridinioid outline with a short apical and two unequally developed antapical horns. The 2a plate is steno-deltaform. The archeopyle is Ia + 3Pa or I + 3Pa.