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Subathua
From Williams et al., 2017:
[Subathua, Khanna and Singh, 1980, p. 307-308
Taxonomic senior synonym: Disphaeria, by implication in Sarkar and Singh (1988, p.41), who transferred the "type species" of Subathua, Subathua sahnii, to Disphaeria - however, Lentin and Williams (1989, p.354) accepted Subathua sahnii as a taxonomic junior synonym of Adnatosphaeridium (as Thalassiphora) patulum.
Type species: Subathua sahnii, Khanna and Singh, 1980 (pl.1, fig.2)]
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Original description: [Khanna and Singh, 1980]:
Description:
Cavate cyst; central body with or without apical and/or antapical and/or lateral horn or horns or small protuberance; periphragm forming parachutelike wing lamella covering the body ventrally; archaeopyle precingular; reflected tabulation not evident; cingulum forming a raised ridge.
Generic Description:
Cavate cyst, usually dorsoventrally flattened; endophragm smooth or granulose forming spherical to oval body with or without apical and/or antapical and/or lateral horn or horns or small protuberance; periphragmal strands arising either from the lateral or laterodorsal region, ramifying, inturning, uniting, forming coarse to fine reticulate parachute, covering the body ventrally; reflected tabulation not evident; cingulum forming a raised ridge; archaeopyle quadrate, precingular; periphragm may have an antapical keel.
Remarks:
Morphologically Subathua is a very close ally of Thalassiphora and seems to have evolved from the same ancestral stock. Like Thalassiphora, thickenings and linear folds in the periphragm of Subathua indicate plate areas. A distinct pericoel has been found between the endophragm and periphragm on the ventral side. From the description and photographs of Thalassiphora balcanica as given by Baltes (1970) it is evident that this species has the same type of cyst organisation as in Subathua. Therefore, the aforesaid species has been transferred to the genus Subathua and a new combination has been instituted as Subathua balcanica.
Affinities/Comparison:
Subathua gen. nov. compares with Thalassiphora Eisenack & Gecht, 1960, Catillopsis Drugg, 1970 and Pterospermopsis Wetzel, 1952 but is distinguishable from all the three. Subathua differs from Thalassiphora by virtue of its attachment of wing lamella with the body. In the former case, the wing lamella is parachutelike and attached to the equatorial or subequatorial dorsal region of the body while in the latter the wing lamella envelopes the whole body. Subathua differs from Catillopsis by having a definite precingular, quadrate archaeopyle whereas Catillopsis has a simple subcircular to circular opening in the centre of the body. In Pterospermopsis the wing lamella extends outwards from the equatorial region of the body but does not cover the body on either side whereas in Subathua the wing lamella covers the body ventrally.
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Stover and Evitt, 1987, p. 207:
Affinities:
We see no taxonomically significant differences between the specimens attributed to the type species of Subathua, S. sahnil and those assigned by many other authors to Thalassiphora. Moreover, the illustrated specimens of S. sahnii (Khanna and Singh 1980, pl. 1, figs. 1-3, 5-9) do not demonstrate that the dorsal surface of the endocyst is without a periphragmal covering (especially figs. 6 and 8), a condition which according to Khanna and Singh is the primary difference between Subathua and Thalassiphora. The species Thalassiphora balcanica Baltes 1971, considered to be a junior synonym of Thalassiphora pelagica by Stover and Evitt 1978 (p. 194), was incorrectly transferred to Subathua by Khanna and Singh 1980, p. 308 (see l.C.B.N. Art. 33, para 4).
[Subathua, Khanna and Singh, 1980, p. 307-308
Taxonomic senior synonym: Disphaeria, by implication in Sarkar and Singh (1988, p.41), who transferred the "type species" of Subathua, Subathua sahnii, to Disphaeria - however, Lentin and Williams (1989, p.354) accepted Subathua sahnii as a taxonomic junior synonym of Adnatosphaeridium (as Thalassiphora) patulum.
Type species: Subathua sahnii, Khanna and Singh, 1980 (pl.1, fig.2)]
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Original description: [Khanna and Singh, 1980]:
Description:
Cavate cyst; central body with or without apical and/or antapical and/or lateral horn or horns or small protuberance; periphragm forming parachutelike wing lamella covering the body ventrally; archaeopyle precingular; reflected tabulation not evident; cingulum forming a raised ridge.
Generic Description:
Cavate cyst, usually dorsoventrally flattened; endophragm smooth or granulose forming spherical to oval body with or without apical and/or antapical and/or lateral horn or horns or small protuberance; periphragmal strands arising either from the lateral or laterodorsal region, ramifying, inturning, uniting, forming coarse to fine reticulate parachute, covering the body ventrally; reflected tabulation not evident; cingulum forming a raised ridge; archaeopyle quadrate, precingular; periphragm may have an antapical keel.
Remarks:
Morphologically Subathua is a very close ally of Thalassiphora and seems to have evolved from the same ancestral stock. Like Thalassiphora, thickenings and linear folds in the periphragm of Subathua indicate plate areas. A distinct pericoel has been found between the endophragm and periphragm on the ventral side. From the description and photographs of Thalassiphora balcanica as given by Baltes (1970) it is evident that this species has the same type of cyst organisation as in Subathua. Therefore, the aforesaid species has been transferred to the genus Subathua and a new combination has been instituted as Subathua balcanica.
Affinities/Comparison:
Subathua gen. nov. compares with Thalassiphora Eisenack & Gecht, 1960, Catillopsis Drugg, 1970 and Pterospermopsis Wetzel, 1952 but is distinguishable from all the three. Subathua differs from Thalassiphora by virtue of its attachment of wing lamella with the body. In the former case, the wing lamella is parachutelike and attached to the equatorial or subequatorial dorsal region of the body while in the latter the wing lamella envelopes the whole body. Subathua differs from Catillopsis by having a definite precingular, quadrate archaeopyle whereas Catillopsis has a simple subcircular to circular opening in the centre of the body. In Pterospermopsis the wing lamella extends outwards from the equatorial region of the body but does not cover the body on either side whereas in Subathua the wing lamella covers the body ventrally.
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Stover and Evitt, 1987, p. 207:
Affinities:
We see no taxonomically significant differences between the specimens attributed to the type species of Subathua, S. sahnil and those assigned by many other authors to Thalassiphora. Moreover, the illustrated specimens of S. sahnii (Khanna and Singh 1980, pl. 1, figs. 1-3, 5-9) do not demonstrate that the dorsal surface of the endocyst is without a periphragmal covering (especially figs. 6 and 8), a condition which according to Khanna and Singh is the primary difference between Subathua and Thalassiphora. The species Thalassiphora balcanica Baltes 1971, considered to be a junior synonym of Thalassiphora pelagica by Stover and Evitt 1978 (p. 194), was incorrectly transferred to Subathua by Khanna and Singh 1980, p. 308 (see l.C.B.N. Art. 33, para 4).