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Trinovantedinium
From Fensome et al., 2019:
Trinovantedinium, Reid, 1977, p.436–437.
Emendations: Harland, 1977b, p.108; Bujak, 1984, p.193; de Verteuil and Norris, 1992, p.406.
Originally (and now) Trinovantedinium, subsequently Protoperidinium subgenus Protoperidinium section Trinovantedinium (combination not validly published). Bradford and Wall (1984, p.48) considered Vozzhennikovia to be the questionable taxonomic senior synonym of this genus. Type: Reid, 1977, pl.1, figs.6–8, as Trinovantedinium capitatum.
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Original description: [Reid, 1977]:
Diagnosis:
Pentagonal cysts with one apical and two antapical horns and without a capsule. Tabulation usually absent but may be indicated by sutures. The girdle and ventral sulcus are well defined to absent. Archeopyle intercalary.
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Emended descriptions:
Harland, 1977:
Diagnosis:
Acapsulate pentagonal cysts with an apical and two symmetrical antapical horns or prominences. Cysts carry a clear ornamentation of sutural and intratabular spines. Cingulum and sulcus clearly defined.
Archeopyle intercalary, I, formed by loss of reflected plate 2a and is probably a broad hexa type.
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Bujak, 1984:
Diagnosis:
Pentagonal protoperidiniacean cyst with one apical and two antapical horns, without pericoels beneath horns.
Cingulum poorly or well defined sulcus absent to well defined. Most of the surface covered by short, solid or hollow spines.
Archeopyle hexa 2a intercalary.
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De Verteuil and Norris, 1992:
Diagnosis:
Proximochorate protoperidiniacean cysts with a pentagonal to subcircular outline in dorsoventral compression. Dorsal epitabulation is hexa with a simple 2a intercalary archeopyle, operculum free; ventral epitabulation variable. Cingulum and sulcus poorly or well defined. Cyst biphragmal with or without pericoels, usually closely adpressed; pericoel development is not pronounced or spectacular. Antapical horns symmetrical or asymmetrical; lateral sides of epicyst convex or straight, apex rounded or angular with or without an apical horn or boss. Surface variably covered by short, penitabular and intratabular, but never sutural, solid or hollow spines or processes. Hollow processes may be distally open or closed. The surface of the phragma may be psilate or carry a simple ornament, but it does not possess any reticulum.
For extended discussion, see Verteuil and Norris, 1992, p. 406-408
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Kurita and Matsuoka 1994, p. 147-148:
Remarks:
The genus was erected on the basis of modern cyst form. In Paleogene geologic records, the genera Spinidinium Cookson and Eisenack. 1962, emend. Lentin and Williams, 1976, Trinovantedinium and Vozzhennikovia Lentin and Williams, 1976 have overlapping stratigraphic occurrences; all the three share similar morphological characteristics including a peridinioid outline, are more or less covered by short processes, and have an intercalary archeopyle and relatively small cyst size. These genera are generally distinguished from each other on the basis of cyst cavation and arrangement of processes. Some authors, however, have pointed out that their morphological range may overlap each other owing to the wide morphological variety within a taxon or to occasionally indeterminate appearance of cyst cavation. For example, Aurisano (1984) and Bradford and Wall (1984) commented on possible synonymies between these genera. This may raise taxonomic uncertainty which will cause difficulties in biostratigraphic application of the genera. From this standpoint, confirmation of the taxonomic relationship between the genera is desirable. Here we strictly follow the emended diagnosis of the genus Trinovantedinium by Bujak (1984), including a cyst wall only with an autophragm and general covering of non-tabular processes. Cysts which consist only of an autophragm but with small pericoels beneath apical and left antapical horns are also included in the genus (as in Bujak, 1984).
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Trinovantedinium Reid, 1977, emend. Harland, 1977b, emend. Bujak, 1984, emend. de Verteuil and Norris, 1992. Emendation by de Verteuil and Norris (1992, p.406), proximochorate protoperidiniacean cysts with a pentagonal to subcircular outline in dorsoventral compression. Dorsal epitabulation is hexa with a simple 2a intercalary archeopyle, operculum free, ventral epitabulation variable. Cingulum and sulcus poorly or well defined. Cyst biphragmal with or without pericoels, usually closely adpressed; pericoel development is not pronounced or spectacular. Antapical horns symmetrical or asymmetrical; lateral sides of epicyst convex or straight, apex rounded or angular with or without an apical horn or boss. Surface variably covered by short, penitabular and intratabular, but never sutural, solid or hollow spines or processes. Hollow processes may be distally open or closed. The surface of the phragma may be psilate or carry a simple ornament, but it does not possess any reticulum. Trinovantedinium differs from Gerlachidium only in having a free rather than posteriorly adnate operculum. It differs from Spinidinium in the less prominent development of the pericoels. Vozzhennikovia is very similar, differing in having nontabular processes and greater asymmetry antapically. Lejeunecysta differs in being without ornament or having only low nontabular ornament. Gippslandia differs in having a very broad hexa intercalary archeopyle. However, one of Stover's paratypes the archeopyle is not as wide as that of the holotype so Gippslandia may be a taxonomic junior synonym of Trinovantedinium. Cristatodinium differs in having sutural crests rather than penitabular processes or spines, and in lacking intratabular ornament on the epicyst. Capillicysta is a cornucavate protoperidiniacean genus reported to have sutural ornamentation.
Trinovantedinium, Reid, 1977, p.436–437.
Emendations: Harland, 1977b, p.108; Bujak, 1984, p.193; de Verteuil and Norris, 1992, p.406.
Originally (and now) Trinovantedinium, subsequently Protoperidinium subgenus Protoperidinium section Trinovantedinium (combination not validly published). Bradford and Wall (1984, p.48) considered Vozzhennikovia to be the questionable taxonomic senior synonym of this genus. Type: Reid, 1977, pl.1, figs.6–8, as Trinovantedinium capitatum.
---------------------------------------------------------------------------------------------------
Original description: [Reid, 1977]:
Diagnosis:
Pentagonal cysts with one apical and two antapical horns and without a capsule. Tabulation usually absent but may be indicated by sutures. The girdle and ventral sulcus are well defined to absent. Archeopyle intercalary.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended descriptions:
Harland, 1977:
Diagnosis:
Acapsulate pentagonal cysts with an apical and two symmetrical antapical horns or prominences. Cysts carry a clear ornamentation of sutural and intratabular spines. Cingulum and sulcus clearly defined.
Archeopyle intercalary, I, formed by loss of reflected plate 2a and is probably a broad hexa type.
-------------------------------------------
Bujak, 1984:
Diagnosis:
Pentagonal protoperidiniacean cyst with one apical and two antapical horns, without pericoels beneath horns.
Cingulum poorly or well defined sulcus absent to well defined. Most of the surface covered by short, solid or hollow spines.
Archeopyle hexa 2a intercalary.
-------------------------------------------
De Verteuil and Norris, 1992:
Diagnosis:
Proximochorate protoperidiniacean cysts with a pentagonal to subcircular outline in dorsoventral compression. Dorsal epitabulation is hexa with a simple 2a intercalary archeopyle, operculum free; ventral epitabulation variable. Cingulum and sulcus poorly or well defined. Cyst biphragmal with or without pericoels, usually closely adpressed; pericoel development is not pronounced or spectacular. Antapical horns symmetrical or asymmetrical; lateral sides of epicyst convex or straight, apex rounded or angular with or without an apical horn or boss. Surface variably covered by short, penitabular and intratabular, but never sutural, solid or hollow spines or processes. Hollow processes may be distally open or closed. The surface of the phragma may be psilate or carry a simple ornament, but it does not possess any reticulum.
For extended discussion, see Verteuil and Norris, 1992, p. 406-408
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Kurita and Matsuoka 1994, p. 147-148:
Remarks:
The genus was erected on the basis of modern cyst form. In Paleogene geologic records, the genera Spinidinium Cookson and Eisenack. 1962, emend. Lentin and Williams, 1976, Trinovantedinium and Vozzhennikovia Lentin and Williams, 1976 have overlapping stratigraphic occurrences; all the three share similar morphological characteristics including a peridinioid outline, are more or less covered by short processes, and have an intercalary archeopyle and relatively small cyst size. These genera are generally distinguished from each other on the basis of cyst cavation and arrangement of processes. Some authors, however, have pointed out that their morphological range may overlap each other owing to the wide morphological variety within a taxon or to occasionally indeterminate appearance of cyst cavation. For example, Aurisano (1984) and Bradford and Wall (1984) commented on possible synonymies between these genera. This may raise taxonomic uncertainty which will cause difficulties in biostratigraphic application of the genera. From this standpoint, confirmation of the taxonomic relationship between the genera is desirable. Here we strictly follow the emended diagnosis of the genus Trinovantedinium by Bujak (1984), including a cyst wall only with an autophragm and general covering of non-tabular processes. Cysts which consist only of an autophragm but with small pericoels beneath apical and left antapical horns are also included in the genus (as in Bujak, 1984).
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Trinovantedinium Reid, 1977, emend. Harland, 1977b, emend. Bujak, 1984, emend. de Verteuil and Norris, 1992. Emendation by de Verteuil and Norris (1992, p.406), proximochorate protoperidiniacean cysts with a pentagonal to subcircular outline in dorsoventral compression. Dorsal epitabulation is hexa with a simple 2a intercalary archeopyle, operculum free, ventral epitabulation variable. Cingulum and sulcus poorly or well defined. Cyst biphragmal with or without pericoels, usually closely adpressed; pericoel development is not pronounced or spectacular. Antapical horns symmetrical or asymmetrical; lateral sides of epicyst convex or straight, apex rounded or angular with or without an apical horn or boss. Surface variably covered by short, penitabular and intratabular, but never sutural, solid or hollow spines or processes. Hollow processes may be distally open or closed. The surface of the phragma may be psilate or carry a simple ornament, but it does not possess any reticulum. Trinovantedinium differs from Gerlachidium only in having a free rather than posteriorly adnate operculum. It differs from Spinidinium in the less prominent development of the pericoels. Vozzhennikovia is very similar, differing in having nontabular processes and greater asymmetry antapically. Lejeunecysta differs in being without ornament or having only low nontabular ornament. Gippslandia differs in having a very broad hexa intercalary archeopyle. However, one of Stover's paratypes the archeopyle is not as wide as that of the holotype so Gippslandia may be a taxonomic junior synonym of Trinovantedinium. Cristatodinium differs in having sutural crests rather than penitabular processes or spines, and in lacking intratabular ornament on the epicyst. Capillicysta is a cornucavate protoperidiniacean genus reported to have sutural ornamentation.