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Systematophora
From Williams et al., 2017:
[Systematophora, Klement, 1960, p. 61-62; Emendations: Brenner, 1988, p. 83; Stancliffe and Sarjeant, 1990, p. 207-208; Riding and Helby, 2001e, p. 123.
Taxonomic junior synonyms:
- Cleistosphaeridium, according to Islam (1993, p.88) — however, Eaton et al. (2001, p.176) retained Cleistosphaeridium;
- Hystrichosphaerina, by implication in Downie and Sarjeant (1965, p.146), who transferred the "type species" of Hystrichosphaerina, Hystrichosphaerina schindewolfii, to Systematophora and Brenner (1988, p.83) — however, Stover and Evitt (1978, p.57–58) and Stancliffe and Sarjeant (1990, p.204) retained Hystrichosphaerina;
- Polystephanephorus, according to Brenner (1988, p.83) — however, Stancliffe and Sarjeant (1990, p.205) retained Polystephanephorus;
- Taeniophora, according to Stover and Evitt (1978, p.84) — however, Sarjeant (1984a, p.166) retained Taeniophora.
Courtinat, Londeix and Pourtoy in Fauconnier and Masure (2004, p.525) listed Taeniophora as a taxonomic junior synonym of Systematophora but did not list the type, Taeniophora iunctispina, within the latter genus. Moreover, Courtinat and Begouën in Fauconnier and Masure (2004, p.545) listed Taeniophora as a separate genus, a treatment followed here.
Type species: Systematophora areolata, Klement, 1960 (pl.9, figs.1–3)]
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Original description: [Klement, 1960]: (Translation: Stover and Evitt, 1978, p. 84):
Description:
Ellipsoidal to spherical central body divided into fields oriented about a girdle area. Fields circular or polygonal, bordered by narrow edges, isolated by intervening spaces. Processes relatively long, simple or forked, in part strongly ramifying, closed distally and generally shortly forked, in part filled in across; distributed in polygonal areas at the angles, more rarely along the sides of the fields, divided by fairly rather closely spaced circular structures. On the basis of a different distribution of the fields, dorso-ventral orientation is possible.
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Modified description:
Stover and Evitt 1978, p. 94-95:
Synopsis:
Cyst skolochorate, gonyaulacaean; body subspherical with 20 to 26 penitabular process groups, each group generally arising from basal ridges and typically without distal connections or trabeculae archeopyle apical, Type (tA).
Description:
Shape: Body subspherical.
Wall relationships: Autophragm only.
Wall features: No parasutural features. Penitabular process groups arise from annular, arcuate, or rectilinear ridges as slender projections that are rarely connected distally, either within a process group or between adjacent groups; numerous isolated paracingular processes may be present. Autophragm between process groups smooth to faintly ornamented, occasionally with low bridgelike ridges.
Paratabulation: Usually indicated incompletely by penitabular process groups; gonyaulacacean, process formula: 3-4`, 6``, 5-6c, 5-6```, 0-1p, 1````, 0-2s. When five postcingular process groups are present, these are interpreted as occurring on paraplates 2``` to 6```.
Archeopyle: Apical, Type (tA); principal archeopyle suture slightly zigzag and parasulcal notch frequently inconspicuous; free operculum with three or four process groups (groups indicating paraplates 1` and 4` may merge).
Paracingulum: Indicated by rectilinear process groups or by transverse alignment of numerous isolated, slender processes.
Parasulcus: Indicated by the absence of processes or by one or two isolated processes.
Size: Intermediate to large.
Affinities:
Systematophora differs from Emmetrocysta and Hystrichosphaerina in not having ring trabeculae at the distal ends of process groups, which those genera have. It differs from Areoligera in being subspherical rather than lenticular and in having well-developed process complexes in the middorsal and midventral surfaces.
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Supplemental description:
Davey, 1982, p. 11:
Description:
The genus Systematophora is characterised by annulate complexes of processes which are best developed in the pre- postcingular and antapical regions, a single complex occupies each paraplate. When well developed the annulate complexes are penitabular in position but often their size is reduced and they become circular and occupy the central part of the individual paraplate. An additional trend is for the basal ridge of the pre- and postcingular complexes to become reduced on the paracingular margin and the processes to become concentrated on the side of the ridge opposite this margin. In other forms the basal ridge is absent and the individual process appear to arise immediately from the cyst wall. The processes are solid, although internal vacuoles may be present; they may be completely separate as in S. areolata Klement, 1960, the type species, or may be linked to neighbouring processes in the complex by a few simple branches or by numerous branches so that an intricate network is developed. All intermediates exist between isolated processes and simple and intricately linked processes. Restricted annulate complexes, composed of two to three individual processes, may develop in the apical region but often here one paraplate bears a single process. This also happens on the parasulcus and on paraplate 1```. Two linearly arranged processes usually occupy each cingular paraplate. The process formula appears to be 4`, 6``, 5-6c, 6```, 1p, 1````, 1-5s. The archaeopyle is apical, formed by the detachment of four apical paraplates as a unit (Type [A])
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Emended descriptions:
Brenner, 1988: (Translation: LPP)
Diagnosis:
Chorate dinoflagellate cyst with apical archaeopyle and intratabular processes, which arise from basal ridges. The basal ridges are developed on the apical, pre- and postcingular paraplates as closed rings. The cingular paraplates consist of short, straight basal ridges with single processes at the ends. The basal ridges of the antapical paraplates are weakly curved and develop a varying number of processes. A single processes is developed on the apex.
Description:
Chorate dinoflagellate cyst with intratabular to penitabular processes arising from closed, round to pentagonal basal ridges.
Archaeopyle apical [4A], operculum tetra-meta (according to Wille, 1985).
The process-groups correspond in size and position to the paratabulae. Ring-like basal ridges are developed on paraplates 1``-6``, 2```-6```, 1````, as, ps and 1p. Curved ridges with one simple process arising from each end are developed on plates 1`-4`. On good preserved opercula on single, thin process could be observed at the apex. Paraplate 1``` is reflected by one or maximal two connected processes.The precingular paraplates consist of two, basal connected processes. One simple, distally branched process is typical for the parasulcal plates ras, rs and ls.
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Stancliffe and Sarjeant, 1990:
Diagnosis:
Phragmochorate dinoflagellate cyst; central body spherical to ellipsoidal with a smooth to granular phragma.
Paratabulation 0-2pr, 4", 6", 5-6c, 5-6```, 1p, 1````, 1-5s.
Penitabular to intratabular clusters of processes are developed on the precingular, postcingular and antapical paraplates. Proximally, each process of a cluster is linked to its neighbor, to a greater or lesser degree, by a crest on the phragma; the resulting grouping can form a circle or ellipse. Processes are solid, of moderate length; branching varies from a single distal bifurcation to very intricate complexes with numerous stages of branching. Inter-process trabeculae or ring trabeculae are not normally developed. The number of processes per cluster varies from 3 to many. In the apical region four penitabular to intratabular clusters may be present or single or paired processes may be developed instead. At the apex, preapical paraplates can be indialted by a single process, a ridge, or not at all. The cingular and sulcal paraplates may be devoid of processes; alternatively, they may have single isolated processes or pairs of processes joined together proximally by a wall or ridge.
Archeopyle apical, type (tA); often with a sulcal notch.
Remarks:
This emended diagnosis is based, to a large degree, on the description of the genus by Davey (1982, p. 11). The primary characteristic of this genus is the basal linxage of most processes into clusters, The presence or absence of paired processes marking the cingulum and sulcus cannot be used as the sole criterion to distinguish this genus from others. Brenner (1988, p. 83) records a solidly process marking the apex, while in certain Argentinian forms studied by Volkheimer and Sarjeant (unpublished data), pn apical paraplates are indicated by lesser surficial ornament. The recent emendation by Brenner (1988, p. 83-85) is not utilised here, since it does not sufficiently stress the morphology of the processes.
Affinities:
The genus is distinguished from Taeniophora Klement 1960 by its lack of transcingular structures. Polystephanephorus Sarjeant 1961 has only five precingular paraplates and Emmetrocysta Stover 1975 does not have cingular processes. Hystrichosphaerina Alberti 1961 has intratabular clusters with very complex branching and ring trabeculae: the latter are not consistently developed by Systematophora. However, these two genera are morphologically and stratigraphically close: indeed, they were considered synonymous by Neale and Sarjeant (1962) and Norris and Sarjeant (1965).
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Poulsen, 1996, p. 64:
Amphorula-Pensseiasphaeridium-Systematophora complex:
Discussion:
The species included within these three genera have a combination of intratabular annulate-arcuate ridges or processes, or large, often deeply digitate processes in the precingular and postcingular paraplate series, and solid cingular processes linked in pairs by a low ridge. Generic differentiation depends on ridge/process morphology, i.e. annulate to arcuate septa in Amphorula; annulate to arcuate complexes composed of simple to complex-linked processes in Systematophora; and tubiform, simple to deeply digitate and fenestrate processes in Perisseiasphaeridium. However, some specimens of Systematophora areolata have processes reduced in length, showing the relationship with Amphorula. In contrast, when the processes of Systematophora are long and the annulate complex becomes narrow at the base, these process complexes are very similar to the processes of, for example, Perisseiasphaeridium pannosum. In one specimen (Pl. 30, Fig. 6), the process complexes on the epicyst are of the Systematophora areolata type, whereas the tubiform processes on the hypocyst are of P. pannosum type.
The Amphorula-Perisseiasphaeridium-Systematophora complex is not considered to be a simple lineage. Davey (1982) regarded Systematophora as the root stock from which early members of the other genera evolved, whereas Stancliffe and Sarjeant (1990) believed that Oligosphaeridium descended from Systematophora, and that Amphorula descended from Taeniophora and Rigaudella and, that both Systematophora and Rigaudella descended from Adnatosphaeridium. Personally, I believe it is more likely that Amphorula descended from Systematophora. Some of the ideas are summarized on Text-Fig. 20, though interrelationships are complex and not fully understood.
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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.
Systematophora Klement, 1960, emend. Brenner, 1988, emend. Stancliffe and Sarjeant, 1990. As emended by Stancliffe and Sarjeant (1990, p.207-208). Phragmochorate dinoflagellate cyst; central body spherical to ellipsoidal with a smooth to granular phragma. Paratabulation 0-2pr, 4`, 6", 5-6c, 5-6``` , 1p, 1``` , 1-5s. Penitabular to intratabular clusters of processes are developed on the precingular, postcingular and antapical paraplates. Proximally, each process of a cluster is linked to its neighbour to a greater or lesser degree, by a crest on the phragma; the resulting grouping can form a circle or ellipse. Processes are soli, of moderate length; branching varies from a single distal bifurcation to very intricate complexes with numerous stages of branching. Inter-process trabeculae or ring trabeculae are not normally developed. The number of processes per cluster varies from 3 to many. In the apical region four penitabular to intratabular clusters may be present or single or paired processes may be developed instead. At the apex, preapical paraplates can be indicated by a single process, a ridge, or not at all. The cingular and sulcal paraplates may be devoid of processes; alternatively, they may have single isolated processes or pairs of processes joined together proximally by a wall or ridge. Archeopyle apical, type (tA); often with a sulcal notch.
[Systematophora, Klement, 1960, p. 61-62; Emendations: Brenner, 1988, p. 83; Stancliffe and Sarjeant, 1990, p. 207-208; Riding and Helby, 2001e, p. 123.
Taxonomic junior synonyms:
- Cleistosphaeridium, according to Islam (1993, p.88) — however, Eaton et al. (2001, p.176) retained Cleistosphaeridium;
- Hystrichosphaerina, by implication in Downie and Sarjeant (1965, p.146), who transferred the "type species" of Hystrichosphaerina, Hystrichosphaerina schindewolfii, to Systematophora and Brenner (1988, p.83) — however, Stover and Evitt (1978, p.57–58) and Stancliffe and Sarjeant (1990, p.204) retained Hystrichosphaerina;
- Polystephanephorus, according to Brenner (1988, p.83) — however, Stancliffe and Sarjeant (1990, p.205) retained Polystephanephorus;
- Taeniophora, according to Stover and Evitt (1978, p.84) — however, Sarjeant (1984a, p.166) retained Taeniophora.
Courtinat, Londeix and Pourtoy in Fauconnier and Masure (2004, p.525) listed Taeniophora as a taxonomic junior synonym of Systematophora but did not list the type, Taeniophora iunctispina, within the latter genus. Moreover, Courtinat and Begouën in Fauconnier and Masure (2004, p.545) listed Taeniophora as a separate genus, a treatment followed here.
Type species: Systematophora areolata, Klement, 1960 (pl.9, figs.1–3)]
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Klement, 1960]: (Translation: Stover and Evitt, 1978, p. 84):
Description:
Ellipsoidal to spherical central body divided into fields oriented about a girdle area. Fields circular or polygonal, bordered by narrow edges, isolated by intervening spaces. Processes relatively long, simple or forked, in part strongly ramifying, closed distally and generally shortly forked, in part filled in across; distributed in polygonal areas at the angles, more rarely along the sides of the fields, divided by fairly rather closely spaced circular structures. On the basis of a different distribution of the fields, dorso-ventral orientation is possible.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Modified description:
Stover and Evitt 1978, p. 94-95:
Synopsis:
Cyst skolochorate, gonyaulacaean; body subspherical with 20 to 26 penitabular process groups, each group generally arising from basal ridges and typically without distal connections or trabeculae archeopyle apical, Type (tA).
Description:
Shape: Body subspherical.
Wall relationships: Autophragm only.
Wall features: No parasutural features. Penitabular process groups arise from annular, arcuate, or rectilinear ridges as slender projections that are rarely connected distally, either within a process group or between adjacent groups; numerous isolated paracingular processes may be present. Autophragm between process groups smooth to faintly ornamented, occasionally with low bridgelike ridges.
Paratabulation: Usually indicated incompletely by penitabular process groups; gonyaulacacean, process formula: 3-4`, 6``, 5-6c, 5-6```, 0-1p, 1````, 0-2s. When five postcingular process groups are present, these are interpreted as occurring on paraplates 2``` to 6```.
Archeopyle: Apical, Type (tA); principal archeopyle suture slightly zigzag and parasulcal notch frequently inconspicuous; free operculum with three or four process groups (groups indicating paraplates 1` and 4` may merge).
Paracingulum: Indicated by rectilinear process groups or by transverse alignment of numerous isolated, slender processes.
Parasulcus: Indicated by the absence of processes or by one or two isolated processes.
Size: Intermediate to large.
Affinities:
Systematophora differs from Emmetrocysta and Hystrichosphaerina in not having ring trabeculae at the distal ends of process groups, which those genera have. It differs from Areoligera in being subspherical rather than lenticular and in having well-developed process complexes in the middorsal and midventral surfaces.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Supplemental description:
Davey, 1982, p. 11:
Description:
The genus Systematophora is characterised by annulate complexes of processes which are best developed in the pre- postcingular and antapical regions, a single complex occupies each paraplate. When well developed the annulate complexes are penitabular in position but often their size is reduced and they become circular and occupy the central part of the individual paraplate. An additional trend is for the basal ridge of the pre- and postcingular complexes to become reduced on the paracingular margin and the processes to become concentrated on the side of the ridge opposite this margin. In other forms the basal ridge is absent and the individual process appear to arise immediately from the cyst wall. The processes are solid, although internal vacuoles may be present; they may be completely separate as in S. areolata Klement, 1960, the type species, or may be linked to neighbouring processes in the complex by a few simple branches or by numerous branches so that an intricate network is developed. All intermediates exist between isolated processes and simple and intricately linked processes. Restricted annulate complexes, composed of two to three individual processes, may develop in the apical region but often here one paraplate bears a single process. This also happens on the parasulcus and on paraplate 1```. Two linearly arranged processes usually occupy each cingular paraplate. The process formula appears to be 4`, 6``, 5-6c, 6```, 1p, 1````, 1-5s. The archaeopyle is apical, formed by the detachment of four apical paraplates as a unit (Type [A])
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended descriptions:
Brenner, 1988: (Translation: LPP)
Diagnosis:
Chorate dinoflagellate cyst with apical archaeopyle and intratabular processes, which arise from basal ridges. The basal ridges are developed on the apical, pre- and postcingular paraplates as closed rings. The cingular paraplates consist of short, straight basal ridges with single processes at the ends. The basal ridges of the antapical paraplates are weakly curved and develop a varying number of processes. A single processes is developed on the apex.
Description:
Chorate dinoflagellate cyst with intratabular to penitabular processes arising from closed, round to pentagonal basal ridges.
Archaeopyle apical [4A], operculum tetra-meta (according to Wille, 1985).
The process-groups correspond in size and position to the paratabulae. Ring-like basal ridges are developed on paraplates 1``-6``, 2```-6```, 1````, as, ps and 1p. Curved ridges with one simple process arising from each end are developed on plates 1`-4`. On good preserved opercula on single, thin process could be observed at the apex. Paraplate 1``` is reflected by one or maximal two connected processes.The precingular paraplates consist of two, basal connected processes. One simple, distally branched process is typical for the parasulcal plates ras, rs and ls.
--------------------------------------------
Stancliffe and Sarjeant, 1990:
Diagnosis:
Phragmochorate dinoflagellate cyst; central body spherical to ellipsoidal with a smooth to granular phragma.
Paratabulation 0-2pr, 4", 6", 5-6c, 5-6```, 1p, 1````, 1-5s.
Penitabular to intratabular clusters of processes are developed on the precingular, postcingular and antapical paraplates. Proximally, each process of a cluster is linked to its neighbor, to a greater or lesser degree, by a crest on the phragma; the resulting grouping can form a circle or ellipse. Processes are solid, of moderate length; branching varies from a single distal bifurcation to very intricate complexes with numerous stages of branching. Inter-process trabeculae or ring trabeculae are not normally developed. The number of processes per cluster varies from 3 to many. In the apical region four penitabular to intratabular clusters may be present or single or paired processes may be developed instead. At the apex, preapical paraplates can be indialted by a single process, a ridge, or not at all. The cingular and sulcal paraplates may be devoid of processes; alternatively, they may have single isolated processes or pairs of processes joined together proximally by a wall or ridge.
Archeopyle apical, type (tA); often with a sulcal notch.
Remarks:
This emended diagnosis is based, to a large degree, on the description of the genus by Davey (1982, p. 11). The primary characteristic of this genus is the basal linxage of most processes into clusters, The presence or absence of paired processes marking the cingulum and sulcus cannot be used as the sole criterion to distinguish this genus from others. Brenner (1988, p. 83) records a solidly process marking the apex, while in certain Argentinian forms studied by Volkheimer and Sarjeant (unpublished data), pn apical paraplates are indicated by lesser surficial ornament. The recent emendation by Brenner (1988, p. 83-85) is not utilised here, since it does not sufficiently stress the morphology of the processes.
Affinities:
The genus is distinguished from Taeniophora Klement 1960 by its lack of transcingular structures. Polystephanephorus Sarjeant 1961 has only five precingular paraplates and Emmetrocysta Stover 1975 does not have cingular processes. Hystrichosphaerina Alberti 1961 has intratabular clusters with very complex branching and ring trabeculae: the latter are not consistently developed by Systematophora. However, these two genera are morphologically and stratigraphically close: indeed, they were considered synonymous by Neale and Sarjeant (1962) and Norris and Sarjeant (1965).
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Poulsen, 1996, p. 64:
Amphorula-Pensseiasphaeridium-Systematophora complex:
Discussion:
The species included within these three genera have a combination of intratabular annulate-arcuate ridges or processes, or large, often deeply digitate processes in the precingular and postcingular paraplate series, and solid cingular processes linked in pairs by a low ridge. Generic differentiation depends on ridge/process morphology, i.e. annulate to arcuate septa in Amphorula; annulate to arcuate complexes composed of simple to complex-linked processes in Systematophora; and tubiform, simple to deeply digitate and fenestrate processes in Perisseiasphaeridium. However, some specimens of Systematophora areolata have processes reduced in length, showing the relationship with Amphorula. In contrast, when the processes of Systematophora are long and the annulate complex becomes narrow at the base, these process complexes are very similar to the processes of, for example, Perisseiasphaeridium pannosum. In one specimen (Pl. 30, Fig. 6), the process complexes on the epicyst are of the Systematophora areolata type, whereas the tubiform processes on the hypocyst are of P. pannosum type.
The Amphorula-Perisseiasphaeridium-Systematophora complex is not considered to be a simple lineage. Davey (1982) regarded Systematophora as the root stock from which early members of the other genera evolved, whereas Stancliffe and Sarjeant (1990) believed that Oligosphaeridium descended from Systematophora, and that Amphorula descended from Taeniophora and Rigaudella and, that both Systematophora and Rigaudella descended from Adnatosphaeridium. Personally, I believe it is more likely that Amphorula descended from Systematophora. Some of the ideas are summarized on Text-Fig. 20, though interrelationships are complex and not fully understood.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Systematophora Klement, 1960, emend. Brenner, 1988, emend. Stancliffe and Sarjeant, 1990. As emended by Stancliffe and Sarjeant (1990, p.207-208). Phragmochorate dinoflagellate cyst; central body spherical to ellipsoidal with a smooth to granular phragma. Paratabulation 0-2pr, 4`, 6", 5-6c, 5-6``` , 1p, 1``` , 1-5s. Penitabular to intratabular clusters of processes are developed on the precingular, postcingular and antapical paraplates. Proximally, each process of a cluster is linked to its neighbour to a greater or lesser degree, by a crest on the phragma; the resulting grouping can form a circle or ellipse. Processes are soli, of moderate length; branching varies from a single distal bifurcation to very intricate complexes with numerous stages of branching. Inter-process trabeculae or ring trabeculae are not normally developed. The number of processes per cluster varies from 3 to many. In the apical region four penitabular to intratabular clusters may be present or single or paired processes may be developed instead. At the apex, preapical paraplates can be indicated by a single process, a ridge, or not at all. The cingular and sulcal paraplates may be devoid of processes; alternatively, they may have single isolated processes or pairs of processes joined together proximally by a wall or ridge. Archeopyle apical, type (tA); often with a sulcal notch.