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Lingulodinium
From Fensome et al., 2019:
Lingulodinium, Wall, 1967, p.109.
Emendations: Wall and Dale in Wall et al., 1973, p.23–24; Dodge, 1989, p.291.
Taxonomic junior synonym: Trioperculodinium, according to Wall and Dale in Wall et al. (1973, p.24).
Type: Deflandre and Cookson, 1955, pl.9, fig.4, as Hystrichosphaeridium machaerophorum.
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Original description: [Wall, 1967]:
Description:
Spherical to ovoid dinoflagellate cysts which, after dehiscence, possess a large, compound epithecal archeopyle representing the loss of either four or five precingular plate-areas. The remainder of the epitheca forms an elongate angular projection or lingula; this corresponds to several (apical, intercalary, and one precingular) plate-areas. The test wall is microgranular to microreticulate and ornamented with numerous intratabular spines.
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Emended description:
Wall and Dale, 1973:
Description:
Spherical to ovoid spinose dinoflagellate cysts with complex precingular archeopyles which may represent the detachment of from one to five precingular plate-areas in the form of a simple operculum (archeopyle type 1P), a compound operculum (archeopyle types 2P, 3P, 4P or 5P) or more rarely an epitractal archeopyle (type AP or TP). The epitract may be reduced to a small angular projection or lingula by loss of opercular or in situ opercular pieces may be outlined by accessory sutures. Spines numerous, intratabular, often flattened, bladelike and pointed, with circular or elongate striate bases and irregular distal spinules or granules.
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Dodge, 1989:
Diagnosis:
Motile cell polyhedral with no spines or horns. More or less median girdle offset by one girdle width. Sulcus straight.
Tabulation: Po, 3`, 3a, 6``, 6c, s, 6```, 1p, 1````.
Thecal plates thick with ridges along the sutures and circular depressions over the surface of the plates. Girdle and sulcal lists present. 6`` is 5-sided and there is a ventral pore on the right side of 1`. The 3` plate is small and situated along the right side of the apical pore. The cyst stage is spherical with a thick rugose wall from which arise numerous spines sometimes bearing spinules on their distal parts.
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Modified description:
Stover and Evitt, 1978, p. 171:
Synopsis:
Cysts skolochorate, acavate; body subspherical with numerous hollow, nontabular processes, which are closed distally; archeopyle simple, compound, or combination, Types P to 5P or Type AP.
Description:
Shape: Body subspherical.
Wall relationships: Cysts acavate; endophragm and periphragm appressed between processes.
Wall features: Parasutural features absent except for archeopyle sutures. Nontabular processes hollow, bases circular to elliptical, tips closed and bluntly rounded to acuminate; surface smooth or with scattered spinules or granules, generally at the distal ends of the processes. Areas between ases of processes granular to punctoreticulate.
Paratabulation: Indicated by archeopyle or by archeopyle and cingulum when archeopyle is compound; paratabulation generally not evident when archeopyle is epicystal.
Archeopyle: Simple or compound precingular or combination, Types P to 5P or Type AP; opercular pieces from precingular archeopyles normally free and separate.
Paracingulum: Generally not indicated; occasionally expressed by faint transverse alignment of processes in the equatorial area.
Parasulcus: Not indicated.
Size: Intermediate to large.
Affinities:
In contrast to most other dinoflagellate cyst genera, the multiple archeopyle types shown by Lingulodinium are exceptional. The hollow, distally closed, bladelike, nontabular processes are characteristic of Lingulodinium, serving to distinguish it from similar-appearing skolochorate cysts, such as Operculodinium and Exochosphaeridium.
Lingulodinium, Wall, 1967, p.109.
Emendations: Wall and Dale in Wall et al., 1973, p.23–24; Dodge, 1989, p.291.
Taxonomic junior synonym: Trioperculodinium, according to Wall and Dale in Wall et al. (1973, p.24).
Type: Deflandre and Cookson, 1955, pl.9, fig.4, as Hystrichosphaeridium machaerophorum.
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Wall, 1967]:
Description:
Spherical to ovoid dinoflagellate cysts which, after dehiscence, possess a large, compound epithecal archeopyle representing the loss of either four or five precingular plate-areas. The remainder of the epitheca forms an elongate angular projection or lingula; this corresponds to several (apical, intercalary, and one precingular) plate-areas. The test wall is microgranular to microreticulate and ornamented with numerous intratabular spines.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended description:
Wall and Dale, 1973:
Description:
Spherical to ovoid spinose dinoflagellate cysts with complex precingular archeopyles which may represent the detachment of from one to five precingular plate-areas in the form of a simple operculum (archeopyle type 1P), a compound operculum (archeopyle types 2P, 3P, 4P or 5P) or more rarely an epitractal archeopyle (type AP or TP). The epitract may be reduced to a small angular projection or lingula by loss of opercular or in situ opercular pieces may be outlined by accessory sutures. Spines numerous, intratabular, often flattened, bladelike and pointed, with circular or elongate striate bases and irregular distal spinules or granules.
---------------------------------
Dodge, 1989:
Diagnosis:
Motile cell polyhedral with no spines or horns. More or less median girdle offset by one girdle width. Sulcus straight.
Tabulation: Po, 3`, 3a, 6``, 6c, s, 6```, 1p, 1````.
Thecal plates thick with ridges along the sutures and circular depressions over the surface of the plates. Girdle and sulcal lists present. 6`` is 5-sided and there is a ventral pore on the right side of 1`. The 3` plate is small and situated along the right side of the apical pore. The cyst stage is spherical with a thick rugose wall from which arise numerous spines sometimes bearing spinules on their distal parts.
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Modified description:
Stover and Evitt, 1978, p. 171:
Synopsis:
Cysts skolochorate, acavate; body subspherical with numerous hollow, nontabular processes, which are closed distally; archeopyle simple, compound, or combination, Types P to 5P or Type AP.
Description:
Shape: Body subspherical.
Wall relationships: Cysts acavate; endophragm and periphragm appressed between processes.
Wall features: Parasutural features absent except for archeopyle sutures. Nontabular processes hollow, bases circular to elliptical, tips closed and bluntly rounded to acuminate; surface smooth or with scattered spinules or granules, generally at the distal ends of the processes. Areas between ases of processes granular to punctoreticulate.
Paratabulation: Indicated by archeopyle or by archeopyle and cingulum when archeopyle is compound; paratabulation generally not evident when archeopyle is epicystal.
Archeopyle: Simple or compound precingular or combination, Types P to 5P or Type AP; opercular pieces from precingular archeopyles normally free and separate.
Paracingulum: Generally not indicated; occasionally expressed by faint transverse alignment of processes in the equatorial area.
Parasulcus: Not indicated.
Size: Intermediate to large.
Affinities:
In contrast to most other dinoflagellate cyst genera, the multiple archeopyle types shown by Lingulodinium are exceptional. The hollow, distally closed, bladelike, nontabular processes are characteristic of Lingulodinium, serving to distinguish it from similar-appearing skolochorate cysts, such as Operculodinium and Exochosphaeridium.