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Prominangularia
From Williams et al., 2017:
[Prominangularia, Jiabo, 1978, p. 47; Emendation: Xu Jinli and Mao Shaozhi, 1989, p. 303.
Chen et al. (1988, p.23) included this genus in the acritarchs "because of the lack of any indications of paratabulation and the absence of an archeopyle, a paracingulum and a parasulcus."; however, Lentin in Lentin and Williams (1989, p.304) considered it to be a freshwater ceratioid dinoflagellate cyst. He Chengquan et al. (2009, p.453) considered Prominangularia to be a subgenus of Bohaidina.
Type species: Prominangularia granulata, Jiabo, 1978 (pl.19, fig.7)]
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Original description: [Jiabo, 1978]: (Translation: Chen et al., 1988):
Diagnosis:
Cysts conical, subtriangular to roundly triangular in outline with one or two folds in the equatorial area (frequently only one seen), and two prominences [out-bulgings] of which either or both may originate in the equatorial or gonal [?angular or corner] areas.
No paracingulum, parasulcus or endocyst discernible.
Surface smooth or ornamented with structures of low relief.
Archeopyle type unknown, perhaps precingular.
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Emended description:
Xu Jin-li and Mao Shao-zhi, 1989: (Translation: Fensome et al., 1991, p. 419; Provisional translation by GSC: courtesy R. Fensome)
Description:
Cyst proximate, polyhedral, triangular in outline. Epitract much larger than hypotract and with a rounded apical protrusion, hypotract short and small with a straight or slightly convex posterior margin. 2-3 girdle projections occur, two well-developed ventrally, and one less developed or degenerate dorsally. 1-2 girdle folds occur above or below the girdle projections. Autophragm smooth or granulate.
Archeopyle is probably combination of type (tA)a+3Ia(?), operculum compound and attached to the cyst.
Tabulation on epitract inferred as 4`, 3a, 7" ([Xu Jin-li and Mao Shao-zhi, 1989b] Fig.8).
(GSC translation):
Proximate cyst, polyhedral, triangular in outline. Epitract much larger than hypotract with a rounded apical protrusion, hypotract short and a small with a straight or slightly convex posterior margin. 2-3 girdle projections developed, two in ventral side well developed while one in dorsal side less developed or degenerated . One or two pieces of girdle folds located above or below the girdle projections. Wall autophragm, smooth or granulate. Archeopyle probably combination of tAa+3Ia(?) type, opercula compound and attached to the cyst. Tabulation on epitract inferred as 4`, 3a, 7`` (fig. 8).
Affinities: (GSC translation):
A re-observation on the holotype indicated that there was not any vestige of archeopyle. Some original figure (Jiabo 1978, pl. 19, fig. 11), however, seems to show a zigzag suture below the apex indicating the apical and intercalary series, and between each intercalary plate. Specimens recovered this time from the type locality show the same phenomenon as observed in Bohaidina. The archeopyle of this genus, therefore, may be inferred as the same as that of Bohaidina. With the undeveloped hypotract, the genus differs from Bohaidina, and from Conicoidium in having girdle projections developed. Trigonopyxis is a cavate cyst with apical archeopyle, which is different from Prominangularia.
[Prominangularia, Jiabo, 1978, p. 47; Emendation: Xu Jinli and Mao Shaozhi, 1989, p. 303.
Chen et al. (1988, p.23) included this genus in the acritarchs "because of the lack of any indications of paratabulation and the absence of an archeopyle, a paracingulum and a parasulcus."; however, Lentin in Lentin and Williams (1989, p.304) considered it to be a freshwater ceratioid dinoflagellate cyst. He Chengquan et al. (2009, p.453) considered Prominangularia to be a subgenus of Bohaidina.
Type species: Prominangularia granulata, Jiabo, 1978 (pl.19, fig.7)]
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Jiabo, 1978]: (Translation: Chen et al., 1988):
Diagnosis:
Cysts conical, subtriangular to roundly triangular in outline with one or two folds in the equatorial area (frequently only one seen), and two prominences [out-bulgings] of which either or both may originate in the equatorial or gonal [?angular or corner] areas.
No paracingulum, parasulcus or endocyst discernible.
Surface smooth or ornamented with structures of low relief.
Archeopyle type unknown, perhaps precingular.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended description:
Xu Jin-li and Mao Shao-zhi, 1989: (Translation: Fensome et al., 1991, p. 419; Provisional translation by GSC: courtesy R. Fensome)
Description:
Cyst proximate, polyhedral, triangular in outline. Epitract much larger than hypotract and with a rounded apical protrusion, hypotract short and small with a straight or slightly convex posterior margin. 2-3 girdle projections occur, two well-developed ventrally, and one less developed or degenerate dorsally. 1-2 girdle folds occur above or below the girdle projections. Autophragm smooth or granulate.
Archeopyle is probably combination of type (tA)a+3Ia(?), operculum compound and attached to the cyst.
Tabulation on epitract inferred as 4`, 3a, 7" ([Xu Jin-li and Mao Shao-zhi, 1989b] Fig.8).
(GSC translation):
Proximate cyst, polyhedral, triangular in outline. Epitract much larger than hypotract with a rounded apical protrusion, hypotract short and a small with a straight or slightly convex posterior margin. 2-3 girdle projections developed, two in ventral side well developed while one in dorsal side less developed or degenerated . One or two pieces of girdle folds located above or below the girdle projections. Wall autophragm, smooth or granulate. Archeopyle probably combination of tAa+3Ia(?) type, opercula compound and attached to the cyst. Tabulation on epitract inferred as 4`, 3a, 7`` (fig. 8).
Affinities: (GSC translation):
A re-observation on the holotype indicated that there was not any vestige of archeopyle. Some original figure (Jiabo 1978, pl. 19, fig. 11), however, seems to show a zigzag suture below the apex indicating the apical and intercalary series, and between each intercalary plate. Specimens recovered this time from the type locality show the same phenomenon as observed in Bohaidina. The archeopyle of this genus, therefore, may be inferred as the same as that of Bohaidina. With the undeveloped hypotract, the genus differs from Bohaidina, and from Conicoidium in having girdle projections developed. Trigonopyxis is a cavate cyst with apical archeopyle, which is different from Prominangularia.