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Wanaea
From Williams et al., 2017:
[Wanaea, Cookson and Eisenack, 1958 p. 57; Emendations: Fensome, 1981, p. 51; Riding and Helby, 2001b, p. 35.
Type species: originally as Epicephalopyxis spectabilis, Deflandre and Cookson, 1955 (pl.3, fig.14)] ; Wanaea spectabilis, Cookson and Eisenack, 1958
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Original description: [Cookson and Eisenack, 1958]:
Diagnosis:
Shell hollow, widely cone-shaped, the edge almost but not completely surrounded by a lace-like edging, a length of about 24 µm being devoid of ornamentation. The edging, which is of variable width, is composed of radially arranged processes, that either anastomose or remain free. The existence of a closing membrane has been suggested by one specimen.
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Modified description:
Stover and Evitt 1978, p. 223:
Synopsis:
Cyst proximochorate, subspherical to broadly biconical; autophragm smooth or with parasutural ridges or septa; paratabulation indicated by parasutural features on hypocyst, or suggested by paracingulum; combination epicystal archeopyle, Types tAtP or tAtPa.
Description:
Shape: Subspherical to broadly biconical; complete specimens rarely seen. Outline of hypocyst circular to broadly elliptical in apical view and may have conspicuous midventral depression.
Wall relationships: Autophragm only.
Wall features: Raised parasutural features lacking (except in paracingular area) or present on hypocyst only. Parasutural ridges or septa smooth to fimbriate and commonly with perforate bases; autophragm smooth or with features of low relief between parasutural ridges or septa.
Paratabulation: Indicated by parasutural features and archeopyle; formula for hypocyst: Xc, 5-6```, 1p, 1````; no ridges or septa observed on epicyst. Archeopyle: Combination epicystal, Types tAtP and tAtPa; principal archeopyle suture immediately anterior of paracingulum. Accessory archeopyle sutures may be absent or weakly developed on operculum, and operculum may be attached ventrally.
Paracingulum: Indicated by one or two transverse equatorial ridges or septa, which are commonly higher (wider) and more strongly ornamented than other ridges or septa.
Parasulcus: Outlined by parasutural ridges, or indicated by midventral depression on hypocyst and interruption of paracingulum.
Size: Intermediate to large.
Affinities:
Wanaea differs from Ctenidodinium in having generally less well-developed ridges or septa, which lack denticulate or spinate crests; in not having the apical paraplates delimited; and in having, on some species, fenestrate equatorial ridges or septa. Biconical forms of Ctenidodinium are not known. Mendicodinium differs from Wanaea in lacking parasutural features and in having a paracingulum that is either not expressed or indicated only faintly. Similarly, Energlynia also lacks well-developed paracingular features and has an antapical horn.
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Emended description:
Fensome, 1981:
Diagnosis:
Organic-walled proximate to proximochorate dinoflagellate cysts, comprising a relatively large, deep, broadly conical to subspherical hypocyst with or without a well developed antapical horn, and a relatively small, shallow, lid-like epicyst. The posterior suture of the cingulum is developed into a more or less broad crest or flange, comprising radially arranged processes, variably interconnected, or reticulate meshwork. Indication of tabulation, other than the archaeopyle and cingular flange, is indistinct or, usually, absent.
The archaeopyle is epitractal (type tAtP or (tAtP)), the epitract being severed apparently along the anterior cingular suture, but often or usually remaining attached.
Affinities: (p. 52-53):
Wanaea is distinguished from other genera of proximate proximochorate dinoflagellate cysts with epitractal archaeopyles by its overall shape and its characteristic flange. Energlynia Sarjeant, 1976 does not possess a cingular flange; however, in other features it is very similar to Wanaea. Energlynia is bajocian to Callovian in age, and is thus almost certainly ancestral to the mostly Late Jurassic Wanaea.
Glossodinium Ioannides et al., 1977 also possesses high cingular crests, but is bicavate, and has a precingular archaeopyle.
A discussion on stratigraphy and evolution of Wanaea and Energlynia is given in Fensome, 1981, p. 56-59.
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Woollam, 1982, p. 47, 50:
Description:
Cysts proximochorate (pterate), 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 generally absent except for a single prominent, lace-like, paracingular flange, interrupted at the parasulcus. The flange consists of radially arranged processes, variably interconnected, and may form a perforate meshwork.
Affinities:
In both Wanaea and Energlynia the principal archaeopyle suture occurs along an equatorial line, interpreted as running above the anterior margin of the paracingulum. The archaeopyle suture divides the operculum, the complete epicyst, from the hypocyst. Suturing is not entire, the operculum remaining attached over a short length of the equatorial margin corresponding in position to the line of interruption of the paracingular flange. The area of attachment is interpreted as the parasulcus (Fig. lA). Loss of the operculum which occasionally occurs is almost certainly due to secondary damage to the rather flimsy parasulcal "hinge". No regularly occurring accessory archaeopyle sutures have been observed in the present study, although secondary splitting of the operculum was observed in a small proportion of specimens, probably due to compression and flattening of the epicyst.
Species recognition in Wanaea is based on the morphology of the paracingular flange (Fig. lB). Four species have been delineated in this way: W. spectabilis, W. clathrata, W. digitata and W. fimbriata. In addition, Fensome ( 1981) split off a fifth species from W. digitata, informally designated W. sp. A. The latter species is found commonly in Europe in the late Callovian and early Oxfordian, and is quite different from W. digitata (s.s.), found only in Australia in the late Jurassic. Wanaea sp. A. of Fensome (op. cit.) is therefore given formal specific status herein, as Wanaea thysanota sp. nov., and W. digitata emended accordingly, being restricted to the Australian type material.
Fensome 1981, has postulated a phylogenetic sequence based on increasing complexity of the paracingular crest, from W. spectabilis to W. digitata, then W. thysanota (W. sp. A.), W. fimbriata and finally W. clathrata. This sequence is difficult to envisage given the spatial/temporal distribution of the individual species.
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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.
Wanaea Cookson and Eisenack, 1958 emend. Fensome, 1981. According to Woollam (1982), species of Wanaea are differentiated on the nature of the paracingular fringe. Emendation from Fensome (1981, p.51), organic-walled proximate to proximochorate dinoflagellate cysts, comprising a relatively large, deep, broadly conical to subspherical hypocyst with or without a well developed antapical horn, and a relatively small, shallow, lid-like epicyst. The posterior suture of the cingulum is developed into a more or less broad crest or flange, comprising radially arranged processes, variably interconnected, or a reticulate meshwork. Indication of tabulation other than the archeopyle and cingular flange, is indistinct or, usually, absent. The archeopyle is epitractal type [tAtP] or [tAtP]@, the epitract being severed apparently along the anterior cingular suture, but often or usually remaining attached.
[Wanaea, Cookson and Eisenack, 1958 p. 57; Emendations: Fensome, 1981, p. 51; Riding and Helby, 2001b, p. 35.
Type species: originally as Epicephalopyxis spectabilis, Deflandre and Cookson, 1955 (pl.3, fig.14)] ; Wanaea spectabilis, Cookson and Eisenack, 1958
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Cookson and Eisenack, 1958]:
Diagnosis:
Shell hollow, widely cone-shaped, the edge almost but not completely surrounded by a lace-like edging, a length of about 24 µm being devoid of ornamentation. The edging, which is of variable width, is composed of radially arranged processes, that either anastomose or remain free. The existence of a closing membrane has been suggested by one specimen.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Modified description:
Stover and Evitt 1978, p. 223:
Synopsis:
Cyst proximochorate, subspherical to broadly biconical; autophragm smooth or with parasutural ridges or septa; paratabulation indicated by parasutural features on hypocyst, or suggested by paracingulum; combination epicystal archeopyle, Types tAtP or tAtPa.
Description:
Shape: Subspherical to broadly biconical; complete specimens rarely seen. Outline of hypocyst circular to broadly elliptical in apical view and may have conspicuous midventral depression.
Wall relationships: Autophragm only.
Wall features: Raised parasutural features lacking (except in paracingular area) or present on hypocyst only. Parasutural ridges or septa smooth to fimbriate and commonly with perforate bases; autophragm smooth or with features of low relief between parasutural ridges or septa.
Paratabulation: Indicated by parasutural features and archeopyle; formula for hypocyst: Xc, 5-6```, 1p, 1````; no ridges or septa observed on epicyst. Archeopyle: Combination epicystal, Types tAtP and tAtPa; principal archeopyle suture immediately anterior of paracingulum. Accessory archeopyle sutures may be absent or weakly developed on operculum, and operculum may be attached ventrally.
Paracingulum: Indicated by one or two transverse equatorial ridges or septa, which are commonly higher (wider) and more strongly ornamented than other ridges or septa.
Parasulcus: Outlined by parasutural ridges, or indicated by midventral depression on hypocyst and interruption of paracingulum.
Size: Intermediate to large.
Affinities:
Wanaea differs from Ctenidodinium in having generally less well-developed ridges or septa, which lack denticulate or spinate crests; in not having the apical paraplates delimited; and in having, on some species, fenestrate equatorial ridges or septa. Biconical forms of Ctenidodinium are not known. Mendicodinium differs from Wanaea in lacking parasutural features and in having a paracingulum that is either not expressed or indicated only faintly. Similarly, Energlynia also lacks well-developed paracingular features and has an antapical horn.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended description:
Fensome, 1981:
Diagnosis:
Organic-walled proximate to proximochorate dinoflagellate cysts, comprising a relatively large, deep, broadly conical to subspherical hypocyst with or without a well developed antapical horn, and a relatively small, shallow, lid-like epicyst. The posterior suture of the cingulum is developed into a more or less broad crest or flange, comprising radially arranged processes, variably interconnected, or reticulate meshwork. Indication of tabulation, other than the archaeopyle and cingular flange, is indistinct or, usually, absent.
The archaeopyle is epitractal (type tAtP or (tAtP)), the epitract being severed apparently along the anterior cingular suture, but often or usually remaining attached.
Affinities: (p. 52-53):
Wanaea is distinguished from other genera of proximate proximochorate dinoflagellate cysts with epitractal archaeopyles by its overall shape and its characteristic flange. Energlynia Sarjeant, 1976 does not possess a cingular flange; however, in other features it is very similar to Wanaea. Energlynia is bajocian to Callovian in age, and is thus almost certainly ancestral to the mostly Late Jurassic Wanaea.
Glossodinium Ioannides et al., 1977 also possesses high cingular crests, but is bicavate, and has a precingular archaeopyle.
A discussion on stratigraphy and evolution of Wanaea and Energlynia is given in Fensome, 1981, p. 56-59.
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Woollam, 1982, p. 47, 50:
Description:
Cysts proximochorate (pterate), 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 generally absent except for a single prominent, lace-like, paracingular flange, interrupted at the parasulcus. The flange consists of radially arranged processes, variably interconnected, and may form a perforate meshwork.
Affinities:
In both Wanaea and Energlynia the principal archaeopyle suture occurs along an equatorial line, interpreted as running above the anterior margin of the paracingulum. The archaeopyle suture divides the operculum, the complete epicyst, from the hypocyst. Suturing is not entire, the operculum remaining attached over a short length of the equatorial margin corresponding in position to the line of interruption of the paracingular flange. The area of attachment is interpreted as the parasulcus (Fig. lA). Loss of the operculum which occasionally occurs is almost certainly due to secondary damage to the rather flimsy parasulcal "hinge". No regularly occurring accessory archaeopyle sutures have been observed in the present study, although secondary splitting of the operculum was observed in a small proportion of specimens, probably due to compression and flattening of the epicyst.
Species recognition in Wanaea is based on the morphology of the paracingular flange (Fig. lB). Four species have been delineated in this way: W. spectabilis, W. clathrata, W. digitata and W. fimbriata. In addition, Fensome ( 1981) split off a fifth species from W. digitata, informally designated W. sp. A. The latter species is found commonly in Europe in the late Callovian and early Oxfordian, and is quite different from W. digitata (s.s.), found only in Australia in the late Jurassic. Wanaea sp. A. of Fensome (op. cit.) is therefore given formal specific status herein, as Wanaea thysanota sp. nov., and W. digitata emended accordingly, being restricted to the Australian type material.
Fensome 1981, has postulated a phylogenetic sequence based on increasing complexity of the paracingular crest, from W. spectabilis to W. digitata, then W. thysanota (W. sp. A.), W. fimbriata and finally W. clathrata. This sequence is difficult to envisage given the spatial/temporal distribution of the individual species.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Wanaea Cookson and Eisenack, 1958 emend. Fensome, 1981. According to Woollam (1982), species of Wanaea are differentiated on the nature of the paracingular fringe. Emendation from Fensome (1981, p.51), organic-walled proximate to proximochorate dinoflagellate cysts, comprising a relatively large, deep, broadly conical to subspherical hypocyst with or without a well developed antapical horn, and a relatively small, shallow, lid-like epicyst. The posterior suture of the cingulum is developed into a more or less broad crest or flange, comprising radially arranged processes, variably interconnected, or a reticulate meshwork. Indication of tabulation other than the archeopyle and cingular flange, is indistinct or, usually, absent. The archeopyle is epitractal type [tAtP] or [tAtP]@, the epitract being severed apparently along the anterior cingular suture, but often or usually remaining attached.