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Chatangiella
From Fensome et al., 2019:
Chatangiella, Vozzhennikova, 1967, p.128–129.
Emendations: Lentin and Williams, 1976, p.51–52; Marshall, 1988, p.199–200 -- however, see Lentin and Vozzhennikova (1990, p.40); Fensome et al., 2016b, p.32.
Taxonomic junior synonyms: Australiella and Cooksoniella, both according to Lentin and Williams (1976, p.155 and p.151–152 respectively). Lentin and Williams (1976, p.93–94) considered Chatangiella to be a possible taxonomic junior synonym of Bulbodinium.
Type: Vozzhennikova, 1967, pl.56, fig.1; pl.57, fig.1, as Chatangiella niiga.
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Original description: [Vozzhennikova, 1967]: (Translation: Lees in Sarjeant, 1971 (Ed.), p. 200)
Description:
Theca longitudinally elongate with strongly to weakly convex to concave sides. Theca divided into nearly equal parts and bearing an apical and
two antapical horns. Transverse furrow slightly spiral, equatorial. Longitudinal furrow situated on hypotheca and extends to antapex. Internal body oval, compressed along the longitudinal axis with its convex sides appressed to the thin sides of the theca. Thecal surface sculptured. Pylome large, polygonal.
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Emended descriptions:
Lentin and Williams, 1976:
Description:
Shape: Pericyst: Ambitus elongate retangular with convex pericingular region. Produced into a broad distally acuminate or rounded apical horn and two symmetrically placed antapical horns, of which the left is always larger, the right being reduced or vestigal. The epipericyst is of more or less constant width, with concave sides, or widens towards the apex with prominent shoulders immediately below the apical horn. There is sometimes an antapical opening in the hypopericyst. Epipericyst and hypopericyst are of approximately the same size. Compression dorso-ventral.
Endocyst: Ambitus subcingular in contact with, or almost touching, the pericyst in the precingular, cingular and postcingular regions. Compression dorso-ventral.
Pericoels: A well developed apical and antapical pericoel.
Phragma: Periphragma: Surface laevigate or with nontabular or penetabular ornamentation as grana, verrucae, tubercles, echinae or spines.
Endophragma: Generally in excess of 1 µm. Surface rarely laevigate, frequently scabrate, granulate or verrucate.
Paratabulation: Pericyst: The paratabular ornamentation denotes the peridinoid paratabulation of 4`, 3a, 7``, 5```, 2````. Paraplates 1`, 2`, and 4` are elongate anterior-posteriorly, 3` is short and broad. Paraplate 2a is omegaform and wider than 4``. The 3``` appears to be the largest of the postcingulars.
Pericingulum: Always present and slightly helicoidal; frequently the only observable evidence of paratabulation. The anterior and posterior parasutures are discontinuous, and represent the posterior penetabular ridges of the postcingulars, respectively. The resultant partite pericingulum therefore should have seven anterior and five posterior ridges. The ridges, or borders, have smooth or denticulate margins.
Perisulcus: Largely restricted to the hypopericyst and widening towards the antapex.
Endocyst: Paratabulation not known other than three anterior intercalaries.
Archaeopyle: Periarchaeopyle: Omegaform intercalary resulting from the complete or partial detachment of paraplate 2a. Perioperculum free or remaining attached along parasuture H4. The shape of the perioperculum seems to reflect the epipericyst and its widest anteriorly. Transverse periarchaeopyle index is 0.33-0.64. Transverse archaeopyle ratio is 0.44-0.81.
Endoarchaeopyle: Where observable is intercalary resulting from the complete or partial detachment of one (2a) or all three anterior intercalary paraplates 1a, 2a, and 3a. Commonly 1a and 3a are completely detached while 2a remains attached along the H4 (2a-4``) parasuture. Archaeopyle formula I/I (2a/2a) or I/3I (2a/ 1-3a).
Dimensions: Pericyst: Length 62-190 µm, breadth 38-125 µm. Endocyst: Length 30-110 µm, breadth 38-109 µm.
Affinities:
Chatangiella is characterized by the distinctive shape of the epipericyst in ambital view, the hepa/pentapartite pericingulum and the omegaform periarchaeopyle, the operculum of which commonly remains attached along parasuture H4. Chatangiella can be readily distinguished from Albertia by its partite pericingulum and omegaform archaeopyle; from Isabelia by its partite pericingulum and frequently developed penetabular ornamentation.
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Marshall, 1988:
Description:
Cyst intermediate to large; compressed ventrodorsally, longitudinally elongate; with a prominent apical and 1-2 antapical horns. Apical horn usually offset by 2 rounded to angular shoulders, occasionally circumcavate. Endocyst outline subcircular to ovidal, width usually greater than length, surface smooth or weakly sculptured. Periphragm smooth or ornamented with elements of low to moderate relief (e.g. grana, bacula, coni and spines); occasionally perforate. Sculpture frequently arranged in intratabular fields or uniformly distributed, occasionally associated with isolated sculptural elements or ridges arranged in parasutural rows. Intratabular sculpture most pronounced equatorially.
Paratabulation defined by intratabular-parasutural sculpture and archaeopyle, peridinacean, formula incomplete: 4`, 3a, 7``, 5```, 2````.
Archaeopyle intercalary, Type I/I or I/3I; periarchaeopyle thetraform to omegaform, operculum free or attached posteriorly.
Paracingulum indicated by distinct rows of ridges or isolated sculptural elements; usually with a partite arrangement; rarely forming 2 continuous lines around the dorsal and edges of the ventral surfaces.
Parasulcus generally indicated only by a shallow depression on midventral surface.
Lentin and Vozzhennikova, 1990, did not accept the emendation of Chatangiella by Marshall, 1988
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Modified description:
Stover and Evitt, 1978, p. 98:
Synopsis:
Cysts proximate, commonly bicavate, rarely circumcavate, compressed, longitudinally elongate; outline subrectangular, typically with short broad-based apical horn and poorly differentiated antapical horns; apical and antapical pericoels normally strongly developed; paratabulation peridiniacean; paracingulum generally tripartite dorsally, rarely continuous; archeopyle intercalary, Types I/l or I/3I; periarcheopyle index 0.4 to 0.6.
Description:
Shape: Cysts compressed, longitudinally elongate; apical margin typically broadly rounded with short wide-based horn; lateral margins characteristically have medial convexity, sharply to vaguely delimited apically and antapically by concavities; antapical margin straight to slightly convex and generally has poorly differentiated horns.
Wall relationships: Cysts commonly bicavate, rarely circumcavate; endocyst outline circular to elliptical; length equal to or less than width.
Wall features: No parasutural features. Periphragm smooth or has features of low to moderate relief (granules, cones, spinules), which may be distributed uniformly, arranged in penitabular rows, and/or occasionally concentrated in intratabular clusters. Endophragm smooth to faintly ornamented.
Paratabulation: Indicated by archeopyle and paracingulum, additionally on some forms by penitabular and intratabular features; peridiniacean; paraplates rarely delimited in other than precingular and postcingular areas, except for archeopyle.
Archeopyle: Intercalary, Types I/I or I/3I; periarcheopyle index 0.4 to 0.6; perioperculum free or attached.
Paracingulum: Indicated by continuous or interrupted transverse parallel ridges or rows of granules, cones, or spinules; commonly tripartite dorsally.
Parasulcus: Not indicated, or expressed as a poorly delimited shallow depression or folded area on the hypocyst.
Size: Intermediate to large.
Affinities:
Chatangiella differs from Isabelidinium in having a generally more rectangular outline, usually with prominent "shoulders" on each side of a broadbased apical horn. In addition, the paracingulum on Chatangiella is nearly always tripartite dorsally, the periphragm is commonly ornamented, and the archeopyle index is normally greater.
Chatangiella, Vozzhennikova, 1967, p.128–129.
Emendations: Lentin and Williams, 1976, p.51–52; Marshall, 1988, p.199–200 -- however, see Lentin and Vozzhennikova (1990, p.40); Fensome et al., 2016b, p.32.
Taxonomic junior synonyms: Australiella and Cooksoniella, both according to Lentin and Williams (1976, p.155 and p.151–152 respectively). Lentin and Williams (1976, p.93–94) considered Chatangiella to be a possible taxonomic junior synonym of Bulbodinium.
Type: Vozzhennikova, 1967, pl.56, fig.1; pl.57, fig.1, as Chatangiella niiga.
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Vozzhennikova, 1967]: (Translation: Lees in Sarjeant, 1971 (Ed.), p. 200)
Description:
Theca longitudinally elongate with strongly to weakly convex to concave sides. Theca divided into nearly equal parts and bearing an apical and
two antapical horns. Transverse furrow slightly spiral, equatorial. Longitudinal furrow situated on hypotheca and extends to antapex. Internal body oval, compressed along the longitudinal axis with its convex sides appressed to the thin sides of the theca. Thecal surface sculptured. Pylome large, polygonal.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended descriptions:
Lentin and Williams, 1976:
Description:
Shape: Pericyst: Ambitus elongate retangular with convex pericingular region. Produced into a broad distally acuminate or rounded apical horn and two symmetrically placed antapical horns, of which the left is always larger, the right being reduced or vestigal. The epipericyst is of more or less constant width, with concave sides, or widens towards the apex with prominent shoulders immediately below the apical horn. There is sometimes an antapical opening in the hypopericyst. Epipericyst and hypopericyst are of approximately the same size. Compression dorso-ventral.
Endocyst: Ambitus subcingular in contact with, or almost touching, the pericyst in the precingular, cingular and postcingular regions. Compression dorso-ventral.
Pericoels: A well developed apical and antapical pericoel.
Phragma: Periphragma: Surface laevigate or with nontabular or penetabular ornamentation as grana, verrucae, tubercles, echinae or spines.
Endophragma: Generally in excess of 1 µm. Surface rarely laevigate, frequently scabrate, granulate or verrucate.
Paratabulation: Pericyst: The paratabular ornamentation denotes the peridinoid paratabulation of 4`, 3a, 7``, 5```, 2````. Paraplates 1`, 2`, and 4` are elongate anterior-posteriorly, 3` is short and broad. Paraplate 2a is omegaform and wider than 4``. The 3``` appears to be the largest of the postcingulars.
Pericingulum: Always present and slightly helicoidal; frequently the only observable evidence of paratabulation. The anterior and posterior parasutures are discontinuous, and represent the posterior penetabular ridges of the postcingulars, respectively. The resultant partite pericingulum therefore should have seven anterior and five posterior ridges. The ridges, or borders, have smooth or denticulate margins.
Perisulcus: Largely restricted to the hypopericyst and widening towards the antapex.
Endocyst: Paratabulation not known other than three anterior intercalaries.
Archaeopyle: Periarchaeopyle: Omegaform intercalary resulting from the complete or partial detachment of paraplate 2a. Perioperculum free or remaining attached along parasuture H4. The shape of the perioperculum seems to reflect the epipericyst and its widest anteriorly. Transverse periarchaeopyle index is 0.33-0.64. Transverse archaeopyle ratio is 0.44-0.81.
Endoarchaeopyle: Where observable is intercalary resulting from the complete or partial detachment of one (2a) or all three anterior intercalary paraplates 1a, 2a, and 3a. Commonly 1a and 3a are completely detached while 2a remains attached along the H4 (2a-4``) parasuture. Archaeopyle formula I/I (2a/2a) or I/3I (2a/ 1-3a).
Dimensions: Pericyst: Length 62-190 µm, breadth 38-125 µm. Endocyst: Length 30-110 µm, breadth 38-109 µm.
Affinities:
Chatangiella is characterized by the distinctive shape of the epipericyst in ambital view, the hepa/pentapartite pericingulum and the omegaform periarchaeopyle, the operculum of which commonly remains attached along parasuture H4. Chatangiella can be readily distinguished from Albertia by its partite pericingulum and omegaform archaeopyle; from Isabelia by its partite pericingulum and frequently developed penetabular ornamentation.
----------------------------------------
Marshall, 1988:
Description:
Cyst intermediate to large; compressed ventrodorsally, longitudinally elongate; with a prominent apical and 1-2 antapical horns. Apical horn usually offset by 2 rounded to angular shoulders, occasionally circumcavate. Endocyst outline subcircular to ovidal, width usually greater than length, surface smooth or weakly sculptured. Periphragm smooth or ornamented with elements of low to moderate relief (e.g. grana, bacula, coni and spines); occasionally perforate. Sculpture frequently arranged in intratabular fields or uniformly distributed, occasionally associated with isolated sculptural elements or ridges arranged in parasutural rows. Intratabular sculpture most pronounced equatorially.
Paratabulation defined by intratabular-parasutural sculpture and archaeopyle, peridinacean, formula incomplete: 4`, 3a, 7``, 5```, 2````.
Archaeopyle intercalary, Type I/I or I/3I; periarchaeopyle thetraform to omegaform, operculum free or attached posteriorly.
Paracingulum indicated by distinct rows of ridges or isolated sculptural elements; usually with a partite arrangement; rarely forming 2 continuous lines around the dorsal and edges of the ventral surfaces.
Parasulcus generally indicated only by a shallow depression on midventral surface.
Lentin and Vozzhennikova, 1990, did not accept the emendation of Chatangiella by Marshall, 1988
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Modified description:
Stover and Evitt, 1978, p. 98:
Synopsis:
Cysts proximate, commonly bicavate, rarely circumcavate, compressed, longitudinally elongate; outline subrectangular, typically with short broad-based apical horn and poorly differentiated antapical horns; apical and antapical pericoels normally strongly developed; paratabulation peridiniacean; paracingulum generally tripartite dorsally, rarely continuous; archeopyle intercalary, Types I/l or I/3I; periarcheopyle index 0.4 to 0.6.
Description:
Shape: Cysts compressed, longitudinally elongate; apical margin typically broadly rounded with short wide-based horn; lateral margins characteristically have medial convexity, sharply to vaguely delimited apically and antapically by concavities; antapical margin straight to slightly convex and generally has poorly differentiated horns.
Wall relationships: Cysts commonly bicavate, rarely circumcavate; endocyst outline circular to elliptical; length equal to or less than width.
Wall features: No parasutural features. Periphragm smooth or has features of low to moderate relief (granules, cones, spinules), which may be distributed uniformly, arranged in penitabular rows, and/or occasionally concentrated in intratabular clusters. Endophragm smooth to faintly ornamented.
Paratabulation: Indicated by archeopyle and paracingulum, additionally on some forms by penitabular and intratabular features; peridiniacean; paraplates rarely delimited in other than precingular and postcingular areas, except for archeopyle.
Archeopyle: Intercalary, Types I/I or I/3I; periarcheopyle index 0.4 to 0.6; perioperculum free or attached.
Paracingulum: Indicated by continuous or interrupted transverse parallel ridges or rows of granules, cones, or spinules; commonly tripartite dorsally.
Parasulcus: Not indicated, or expressed as a poorly delimited shallow depression or folded area on the hypocyst.
Size: Intermediate to large.
Affinities:
Chatangiella differs from Isabelidinium in having a generally more rectangular outline, usually with prominent "shoulders" on each side of a broadbased apical horn. In addition, the paracingulum on Chatangiella is nearly always tripartite dorsally, the periphragm is commonly ornamented, and the archeopyle index is normally greater.