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Energlynia
From Williams et al., 2017:
[Energlynia, Sarjeant, 1976b, p. 164
Type species: originally as Wanaea acollaris, Dodekova, 1975 (pl.3, figs.1–4)] ; Energlynia acollaris, Sarjeant, 1978
(The original type of the genus Energlynia, E. kyrbasia Sarjeant, 1976, was considered to be a jr. synonym of E. acollaris by Fensome, 1981 and Fenton and Fisher, 1978. The latter species therefore becomes the type of the genus.)
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Original description: [Sarjeant, 1976]:
Diagnosis:
Proximate dinoflagellate cysts of ovoidal to broadly ellipsoidal ambitus, with or without an apical horn but consistently with a single antapical horn, asymmetrically situated, which may or may not bear a single spine or branched process at its tips. The hypotract is typically larger than the epitract.
Archeopyle epitractal, the epitract being shed either as a unit or (more frequently) by progressive loss of the precingular plate-areas from the dorsal and eventually from the ventral surface, a ventral connection between apex and hypotract persisting longest.
Plate boundaries marked by very low and inconspicuous ridges, by lines of spines (with or without distal interconnections), or not marked; tabulation thus difficult to determine, but apparently 4`, 2a, 6``, ?6c, 6````, 1p, ?2````. (One anterior intercalary plate is positioned to the right of the sulcus, the other on the dorsal surface.) Short spinelets or granules, punctae or an infrareticulate patterning may be developed or absent. Typically encountered as hypotracts, sometimes with the epitract (or fragments of it) associated with or attached to them or within them. Complete cysts are rare.
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Modified descriptions:
Stover and Evitt 1978, p. 205-206:
Synopsis:
Cysts proximate, subspherical to ellipsoidal with single asymmetrically placed antapical horn; paratabulation commonly obscure, not indicated, or shown by faint parasutural lines, low ridges, or rows of spines; hypocyst significantly larger than epicyst; combination archeopyle, Types tAtP or A+1-6P.
Description:
Shape: Subspherical to ellipsoidal with a single asymmetrically placed antapical horn; epicyst smaller and lower arched than the significantly larger hypocyst.
Wall relationships: Autophragm only.
Wall features: Parasutural features are absent or consist of faint lines, very low inconspicuous ridges, or rows of spines; autophragm faintly ornamented.
Paratabulation: Indicated by poorly developed parasutural features or not expressed at all; provisional formula: 4`, 2a, 6``, ?6c, 6```, 1p, ?2````. Archeopyle: Combination, Type tAtP or A+1-6P; operculum released as a single piece or, more frequently, as two to seven opercular pieces through the progressive release of precingular paraplates from the dorsal to the ventral surface.
Paracingulum: Not indicated, or expressed on hypocyst by faint, transverse, parallel features immediately below the principal archeopyle margin; may be subdivided.
Parasulcus: Poorly delimited narrow depression extending, apparently, from apex to antapex.
Size: Intermediate.
Affinities:
Energlynia differs from Ctenidodinium in having an apical horn and in either lacking parasutural features or having less well-developed ones.
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Synopsis:
Fensome, 1981, p. 49-50:
Synopsis of diagnosis:
Proximate organic-walled subovoidal to broadly biconical dinoflagellate cysts with a relatively large hypotract, usually with an antapical horn, and a relatively small, shallow epitract, with or without an apical horn. The autophragm is smooth or, more usually, ornamented with granulae, short spinulae, punctae, or with a fine reticulum. A gonyaulacoid tabulation is absent or weakly indicated; in the latter case the sutures are marked by rows of short spinelets or low ridges. The posterior cingular suture is never marked by a crest or flange, and is not, or only slightly, more strongly marked than the anterior cingular suture.
The archaeopyle is epitractal, type (tAtP)a or tAtP; the epitract may begin to break up into its constituent plates, or alternatively may remain intact during archaeopyle formation.
Affinities:
Energlynia is differentiated from Wanaea essentially by its lack of a cingular flange, not by its possession of a gonyaulacoid tabulation pattern. The spines present at the tip of the antapical horn in many specimens of E. acollaris are reminiscent of the apicular and "antapicular" structures present in many pareodinioid cysts.
A discussion on stratigraphy and evolution of Energlynia and Wanaea is given in Fensome, 1981, p. 56-59.
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Supplemental description:
Woollam, 1982, p. 47:
Description:
Cysts proximate, broadly biconical; hypocyst large, cone- shaped with a short antapical horn; epicyst relatively small, slightly apically convex, circular in polar view.
Archaeopyle epicystal; operculum simple, compound, corresponding to all paraplates of the epicyst, attached ventrally.
Paratabulation absent, or indistinct, gonyaulacoid, indicated by low parasutural or rows of spinelets; paracingulum may be more distinct, indicated by a low ridge or nebulous rim.
Affinities:
No regularly occurring accessory archaeopyle sutures have been observed in the present study. This is in contrast to the observations of Sarjeant (1976), Stover & Evitt (1978) and Fensome (1981). However, random splitting of the operculum occasionally occurs along parasutures and/or within paraplate areas, probably caused by damage during compression and flattening of the epicyst.
Under normal working conditions, the consistent recognition of species of Energlynia is difficult. The pronouncement of Fensome (1981), recognising only E. acollaris and E. indotata as separate species, is provisionally accepted here. However, examination of the topotype specimens of E. acollaris and its junior synonym "E. kyrbasia" illustrated in Pl. 1, figs. 1, 2, 4, 5, shows clear differences in size, details of shape and surface ornament, and paratabulation development between the two "species". They may possibly be explained as ecophenotypic varieties. E. indotata (Pl. 1, figs. 3, 6, 7) is characterised by a relatively smooth cyst wall with a nebulous paracingular rim; Pl. 1, fig. 3 shows a faintly paratabulate, detached epicyst of E. indotata.
[Energlynia, Sarjeant, 1976b, p. 164
Type species: originally as Wanaea acollaris, Dodekova, 1975 (pl.3, figs.1–4)] ; Energlynia acollaris, Sarjeant, 1978
(The original type of the genus Energlynia, E. kyrbasia Sarjeant, 1976, was considered to be a jr. synonym of E. acollaris by Fensome, 1981 and Fenton and Fisher, 1978. The latter species therefore becomes the type of the genus.)
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Sarjeant, 1976]:
Diagnosis:
Proximate dinoflagellate cysts of ovoidal to broadly ellipsoidal ambitus, with or without an apical horn but consistently with a single antapical horn, asymmetrically situated, which may or may not bear a single spine or branched process at its tips. The hypotract is typically larger than the epitract.
Archeopyle epitractal, the epitract being shed either as a unit or (more frequently) by progressive loss of the precingular plate-areas from the dorsal and eventually from the ventral surface, a ventral connection between apex and hypotract persisting longest.
Plate boundaries marked by very low and inconspicuous ridges, by lines of spines (with or without distal interconnections), or not marked; tabulation thus difficult to determine, but apparently 4`, 2a, 6``, ?6c, 6````, 1p, ?2````. (One anterior intercalary plate is positioned to the right of the sulcus, the other on the dorsal surface.) Short spinelets or granules, punctae or an infrareticulate patterning may be developed or absent. Typically encountered as hypotracts, sometimes with the epitract (or fragments of it) associated with or attached to them or within them. Complete cysts are rare.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Modified descriptions:
Stover and Evitt 1978, p. 205-206:
Synopsis:
Cysts proximate, subspherical to ellipsoidal with single asymmetrically placed antapical horn; paratabulation commonly obscure, not indicated, or shown by faint parasutural lines, low ridges, or rows of spines; hypocyst significantly larger than epicyst; combination archeopyle, Types tAtP or A+1-6P.
Description:
Shape: Subspherical to ellipsoidal with a single asymmetrically placed antapical horn; epicyst smaller and lower arched than the significantly larger hypocyst.
Wall relationships: Autophragm only.
Wall features: Parasutural features are absent or consist of faint lines, very low inconspicuous ridges, or rows of spines; autophragm faintly ornamented.
Paratabulation: Indicated by poorly developed parasutural features or not expressed at all; provisional formula: 4`, 2a, 6``, ?6c, 6```, 1p, ?2````. Archeopyle: Combination, Type tAtP or A+1-6P; operculum released as a single piece or, more frequently, as two to seven opercular pieces through the progressive release of precingular paraplates from the dorsal to the ventral surface.
Paracingulum: Not indicated, or expressed on hypocyst by faint, transverse, parallel features immediately below the principal archeopyle margin; may be subdivided.
Parasulcus: Poorly delimited narrow depression extending, apparently, from apex to antapex.
Size: Intermediate.
Affinities:
Energlynia differs from Ctenidodinium in having an apical horn and in either lacking parasutural features or having less well-developed ones.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Synopsis:
Fensome, 1981, p. 49-50:
Synopsis of diagnosis:
Proximate organic-walled subovoidal to broadly biconical dinoflagellate cysts with a relatively large hypotract, usually with an antapical horn, and a relatively small, shallow epitract, with or without an apical horn. The autophragm is smooth or, more usually, ornamented with granulae, short spinulae, punctae, or with a fine reticulum. A gonyaulacoid tabulation is absent or weakly indicated; in the latter case the sutures are marked by rows of short spinelets or low ridges. The posterior cingular suture is never marked by a crest or flange, and is not, or only slightly, more strongly marked than the anterior cingular suture.
The archaeopyle is epitractal, type (tAtP)a or tAtP; the epitract may begin to break up into its constituent plates, or alternatively may remain intact during archaeopyle formation.
Affinities:
Energlynia is differentiated from Wanaea essentially by its lack of a cingular flange, not by its possession of a gonyaulacoid tabulation pattern. The spines present at the tip of the antapical horn in many specimens of E. acollaris are reminiscent of the apicular and "antapicular" structures present in many pareodinioid cysts.
A discussion on stratigraphy and evolution of Energlynia and Wanaea is given in Fensome, 1981, p. 56-59.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Supplemental description:
Woollam, 1982, p. 47:
Description:
Cysts proximate, broadly biconical; hypocyst large, cone- shaped with a short antapical horn; epicyst relatively small, slightly apically convex, circular in polar view.
Archaeopyle epicystal; operculum simple, compound, corresponding to all paraplates of the epicyst, attached ventrally.
Paratabulation absent, or indistinct, gonyaulacoid, indicated by low parasutural or rows of spinelets; paracingulum may be more distinct, indicated by a low ridge or nebulous rim.
Affinities:
No regularly occurring accessory archaeopyle sutures have been observed in the present study. This is in contrast to the observations of Sarjeant (1976), Stover & Evitt (1978) and Fensome (1981). However, random splitting of the operculum occasionally occurs along parasutures and/or within paraplate areas, probably caused by damage during compression and flattening of the epicyst.
Under normal working conditions, the consistent recognition of species of Energlynia is difficult. The pronouncement of Fensome (1981), recognising only E. acollaris and E. indotata as separate species, is provisionally accepted here. However, examination of the topotype specimens of E. acollaris and its junior synonym "E. kyrbasia" illustrated in Pl. 1, figs. 1, 2, 4, 5, shows clear differences in size, details of shape and surface ornament, and paratabulation development between the two "species". They may possibly be explained as ecophenotypic varieties. E. indotata (Pl. 1, figs. 3, 6, 7) is characterised by a relatively smooth cyst wall with a nebulous paracingular rim; Pl. 1, fig. 3 shows a faintly paratabulate, detached epicyst of E. indotata.