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Epiplosphaera
From Williams et al., 2017:
[Epiplosphaera, Klement, 1960, p.73; Emendations: Brenner, 1988, p. 50
Type species: Epiplosphaera bireticulata, Klement, 1960 (pl.8, figs.1–2)]
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Original description: [Klement, 1960]: (Translation: Stover and Evitt, 1978, p. 46):
Description:
Ellipsoidal shells with fine, irregularly polygonal, small-meshed reticulate ornamentation on the surface.
Processes arising at the points of junction of the basal network are relatively short, simple or with short distal bifurcations, rarely isolated, mostly interconnected by fringes or by thick ledges perpendicular to the surface of the shell. These form either closed structures in the shape of a second, much larger meshed polygonal network of crests, or run as linear marginal fringes or produce a regularly trapezoidal pattern predominantly in the longitudinal and transverse directions.
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Modified description:
Stover and Evitt, 1978, p. 46-47;
Synopsis:
Cysts proximochorate, body subspherical to ellipsoidal, typically bireticulate, with crestal spines or septa; latter may be associated with
distal reticulation whose lumina tend to be larger than those of underlying reticulation; archeopyle apical, Type tA.
Description:
Shape: Body subspherical to ellipsoidal; peripheral outline irregular, jagged.
Wall relationships: Autophragm only.
Wall features: No parasutural features. Autophragm with small meshed reticulum; isolated spines arise at intersections of muri or, more commonly, interconnected spines or septa form a second, more distal reticulum whose lumina tend to be larger than those of underlying reticulum. Autophragm between muri smooth or finely ornamented.
Paratabulation: Indicated by archeopyle only, formula unknown.
Archeopyle: Apical, Type tA; operculum free.
Paracingulum: Not indicated.
Parasulcus: Not indicated.
Size: Intermediate.
Affinities:
Epiplosphaera differs from Ellipsoidictym in being typically bireticulate, and in having higher muri or septa that are typically uneven distally on Ellipsoidictyum, the muri are essentially uniform in height so that the outline of the cyst is fairly smooth, not irregular and jagged as in Epiplosphaera.
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Emended description:
Brenner, 1988: (Translation: Poulsen, 1992, p. 66):
Diagnosis:
Proximochorate dinoflagellate cyst with an apical archeopyle. The cyst wall consists of a thin inner membrane and a solid to fine porous main cyst wall. The surface of the cyst bears an ornament of septa from which normally short bifid spines arise. The spines are often interconnected by delicate septa or membranes. The septa form an irregular network, which occurs in different stages of reduction. The reduction of the ridge network takes place either by shortening, producing an incomplete network, or by preferential development of the parasutures. Depending on the stage of reduction, the paracingulum, the parasulcus, or the parasutures are recognized. The paratabulation is gonyaulacoid.
Affinities:
The various forms of Epiplosphaera differ from the Valensiella - Ellipsoidictyum - Histiophora group in the processes, arranged on ridges. The various reduction stages of the surface ornamentation, as occurring in the Valensiella - Ellipsoidictyum - Histiophora group, can also be observed in the various forms of Epiplosphaera.
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Supplemental description:
Poulsen, 1992, p. 66:
Description:
Although this species (sic) was originally described as one in which paratabulation is indicated by the archeopyle only (Klement, 1960; Stover & Evitt, 1978), indications of paratabulation may be visible in certain, rather specific, orientations. The gonyaulacoid paraplate pattern is indicated by the archeopyle sutures. No irregular break is noticed in the archeopyle sutures; the operculum is free as previously stated by Stover & Evitt (1978).
Affinities:
Epiplosphaera differs from Ellipsoidictyum in having spines, which are interconnected (sic, add "by") muri or septa that are typically uneven distally. Ellipsoidictyum lacks spines and has muri that are essentially uniform in height so that the outline of the cyst is fairly smooth, not irregular and jagged as in Epiplosphaera. Aldorfia and Valensiella have an autophragm with an ectophragm, the archeopyle of Aldorfia is precingular.
Egmontodonium and Histiophora has (sic, read: have) both well expressed parasutures with only minor indication of a non-tabular reticulum (see Brenner, 1988, fig. 19).
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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.
Epiplosphaera Klement, 1960, emend. Brenner, 1988, was revised by Brenner (1988) as follows, proximochorate dinocyst with apical archeopyle. The cyst wall consists of a thin inner membrane and a solid to finely perforate main wall. The cyst surface has an ornament of septa from which normally arise short, mostly bifid processes. The processes are often interconnected by delicate septa or membranes. The septa form an irregular network, which occurs in different stages of reduction. The reduction of the ridge network results either through shortening of the ridges so that an incomplete reticulum is formed, or through preferential development of the parasutures. Depending on the stage of reduction, the paracingulum, parasulcus and parasutures can be distinguished. The paratabulation is gonyaulacoid. According to Feist-Burkhardt and Monteil (1997), Epiplosphaera differs form Ellipsoidictyum and Valensiella in the presence of processes on the crests. Poulsen (1992, p.66) stated that Epiplosphaera differs form Ellipsoidictyum in having spines which are interconnected (by) muri or septa that are typically uneven distally. Ellipsoidictyum lacks spines and has muri that are essentially uniform in height so that the outline of the cyst is fairly smooth, not irregular and jagged as in Epiplosphaera.
[Epiplosphaera, Klement, 1960, p.73; Emendations: Brenner, 1988, p. 50
Type species: Epiplosphaera bireticulata, Klement, 1960 (pl.8, figs.1–2)]
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Original description: [Klement, 1960]: (Translation: Stover and Evitt, 1978, p. 46):
Description:
Ellipsoidal shells with fine, irregularly polygonal, small-meshed reticulate ornamentation on the surface.
Processes arising at the points of junction of the basal network are relatively short, simple or with short distal bifurcations, rarely isolated, mostly interconnected by fringes or by thick ledges perpendicular to the surface of the shell. These form either closed structures in the shape of a second, much larger meshed polygonal network of crests, or run as linear marginal fringes or produce a regularly trapezoidal pattern predominantly in the longitudinal and transverse directions.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Modified description:
Stover and Evitt, 1978, p. 46-47;
Synopsis:
Cysts proximochorate, body subspherical to ellipsoidal, typically bireticulate, with crestal spines or septa; latter may be associated with
distal reticulation whose lumina tend to be larger than those of underlying reticulation; archeopyle apical, Type tA.
Description:
Shape: Body subspherical to ellipsoidal; peripheral outline irregular, jagged.
Wall relationships: Autophragm only.
Wall features: No parasutural features. Autophragm with small meshed reticulum; isolated spines arise at intersections of muri or, more commonly, interconnected spines or septa form a second, more distal reticulum whose lumina tend to be larger than those of underlying reticulum. Autophragm between muri smooth or finely ornamented.
Paratabulation: Indicated by archeopyle only, formula unknown.
Archeopyle: Apical, Type tA; operculum free.
Paracingulum: Not indicated.
Parasulcus: Not indicated.
Size: Intermediate.
Affinities:
Epiplosphaera differs from Ellipsoidictym in being typically bireticulate, and in having higher muri or septa that are typically uneven distally on Ellipsoidictyum, the muri are essentially uniform in height so that the outline of the cyst is fairly smooth, not irregular and jagged as in Epiplosphaera.
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Emended description:
Brenner, 1988: (Translation: Poulsen, 1992, p. 66):
Diagnosis:
Proximochorate dinoflagellate cyst with an apical archeopyle. The cyst wall consists of a thin inner membrane and a solid to fine porous main cyst wall. The surface of the cyst bears an ornament of septa from which normally short bifid spines arise. The spines are often interconnected by delicate septa or membranes. The septa form an irregular network, which occurs in different stages of reduction. The reduction of the ridge network takes place either by shortening, producing an incomplete network, or by preferential development of the parasutures. Depending on the stage of reduction, the paracingulum, the parasulcus, or the parasutures are recognized. The paratabulation is gonyaulacoid.
Affinities:
The various forms of Epiplosphaera differ from the Valensiella - Ellipsoidictyum - Histiophora group in the processes, arranged on ridges. The various reduction stages of the surface ornamentation, as occurring in the Valensiella - Ellipsoidictyum - Histiophora group, can also be observed in the various forms of Epiplosphaera.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Supplemental description:
Poulsen, 1992, p. 66:
Description:
Although this species (sic) was originally described as one in which paratabulation is indicated by the archeopyle only (Klement, 1960; Stover & Evitt, 1978), indications of paratabulation may be visible in certain, rather specific, orientations. The gonyaulacoid paraplate pattern is indicated by the archeopyle sutures. No irregular break is noticed in the archeopyle sutures; the operculum is free as previously stated by Stover & Evitt (1978).
Affinities:
Epiplosphaera differs from Ellipsoidictyum in having spines, which are interconnected (sic, add "by") muri or septa that are typically uneven distally. Ellipsoidictyum lacks spines and has muri that are essentially uniform in height so that the outline of the cyst is fairly smooth, not irregular and jagged as in Epiplosphaera. Aldorfia and Valensiella have an autophragm with an ectophragm, the archeopyle of Aldorfia is precingular.
Egmontodonium and Histiophora has (sic, read: have) both well expressed parasutures with only minor indication of a non-tabular reticulum (see Brenner, 1988, fig. 19).
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Epiplosphaera Klement, 1960, emend. Brenner, 1988, was revised by Brenner (1988) as follows, proximochorate dinocyst with apical archeopyle. The cyst wall consists of a thin inner membrane and a solid to finely perforate main wall. The cyst surface has an ornament of septa from which normally arise short, mostly bifid processes. The processes are often interconnected by delicate septa or membranes. The septa form an irregular network, which occurs in different stages of reduction. The reduction of the ridge network results either through shortening of the ridges so that an incomplete reticulum is formed, or through preferential development of the parasutures. Depending on the stage of reduction, the paracingulum, parasulcus and parasutures can be distinguished. The paratabulation is gonyaulacoid. According to Feist-Burkhardt and Monteil (1997), Epiplosphaera differs form Ellipsoidictyum and Valensiella in the presence of processes on the crests. Poulsen (1992, p.66) stated that Epiplosphaera differs form Ellipsoidictyum in having spines which are interconnected (by) muri or septa that are typically uneven distally. Ellipsoidictyum lacks spines and has muri that are essentially uniform in height so that the outline of the cyst is fairly smooth, not irregular and jagged as in Epiplosphaera.