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Jainiella
From Fensome et al., 2019:
Jainiella, Khowaja-Ateequzzaman and Garg, 1995, p.245–246.
Type: Khowaja-Ateequzzaman and Garg, 1995, pl.1, figs.1–2, as Jainiella breviornata.
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Original description: [Khowaja-Ateequzzaman and Garg, 1995, p.245–246]:
Jainiella gen. nov.
Type species - Jainiella breviomata sp. nov.
Diagnosis -- Autocyst subspherical to oval; proximate to proximochorate: parasutural features absent, archaeopyle intercalary, type 31: operculum free.
Etymology - The genus is named after Dr Krishna P. Jain who has pioneered the study of fossil dinoflagellates in India.
Remarks - The new genus Jainiella is characterised by its hornless autocyst with intercalary, type 31 archaeopyle. In archaeopyle architecture, Jainiella gen. nov. resembles Ginginodinium Cookson & Eisenack 1960 emend. Lentin & Williams 1976; Trivalvadinium Islam 1983 emended herein and Trithyrodinium Drugg 1967 emend Lentin & Williams 1976, but differs from all these taxa in not being biphragmal (having only an
autophragm) and in lacking apical and antapical horns (Table 1).
Islam (1983a, pp. 344-346) established Trivalvadinium with the following diagnosis: "Cyst peridinioid and roundly pentagonal to subspherical:
horns, if present, vestigial: laterally to dorsoventrally compressed: proximochorate: acavate to narrowly circumcavate when possessing two mildly ornamented phragma; numerous or relatively fewer nontabular processes, solid, tubular or thinly tubular: archaeopyle intercalary type 31/31 or 31 when an autocyst, operculum free, opercular pieces not found." He designated Trivalvadinium fonnosum as its type species. In a
subsequent publication (1983b, p. 90) he described another species Trivalvadinium plenum which is characterised by having autocyst with intercalary archaeopyle type 31 He further remarked, "Generic assignment of the species been based on overall morphology and 31 archaeopyle, but this is an autocyst as against biphragmal T. formosum, the type of the genus. Generic reallocation of T. plenum n. sp. may therefore be necessary when appropriate."
In view of the above opinion (Islam, 1983b, p. 90) it is apparent that cysts with two different types of wall structures (autocyst and biphragmal cyst) should be accomodated in two different genera. A new genus Jainiella is therefore erected to receive the single walled cysts (autocyst). Accordingly the genus Trivalvadinium is emended herein excluding the autocyst.
Trivalvadinium plenum Islam 1983b (p. 90; pl. 4, figs 4-6) having autocyst is thus transferred to the new genus.
Jainiella plena (Islam) comb. nov. = Triualvadinium plenum Islam 1983b, p. 90; pI. 4, figs 4-6; Palynology 7 : 71-92.
Jainiella, Khowaja-Ateequzzaman and Garg, 1995, p.245–246.
Type: Khowaja-Ateequzzaman and Garg, 1995, pl.1, figs.1–2, as Jainiella breviornata.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Khowaja-Ateequzzaman and Garg, 1995, p.245–246]:
Jainiella gen. nov.
Type species - Jainiella breviomata sp. nov.
Diagnosis -- Autocyst subspherical to oval; proximate to proximochorate: parasutural features absent, archaeopyle intercalary, type 31: operculum free.
Etymology - The genus is named after Dr Krishna P. Jain who has pioneered the study of fossil dinoflagellates in India.
Remarks - The new genus Jainiella is characterised by its hornless autocyst with intercalary, type 31 archaeopyle. In archaeopyle architecture, Jainiella gen. nov. resembles Ginginodinium Cookson & Eisenack 1960 emend. Lentin & Williams 1976; Trivalvadinium Islam 1983 emended herein and Trithyrodinium Drugg 1967 emend Lentin & Williams 1976, but differs from all these taxa in not being biphragmal (having only an
autophragm) and in lacking apical and antapical horns (Table 1).
Islam (1983a, pp. 344-346) established Trivalvadinium with the following diagnosis: "Cyst peridinioid and roundly pentagonal to subspherical:
horns, if present, vestigial: laterally to dorsoventrally compressed: proximochorate: acavate to narrowly circumcavate when possessing two mildly ornamented phragma; numerous or relatively fewer nontabular processes, solid, tubular or thinly tubular: archaeopyle intercalary type 31/31 or 31 when an autocyst, operculum free, opercular pieces not found." He designated Trivalvadinium fonnosum as its type species. In a
subsequent publication (1983b, p. 90) he described another species Trivalvadinium plenum which is characterised by having autocyst with intercalary archaeopyle type 31 He further remarked, "Generic assignment of the species been based on overall morphology and 31 archaeopyle, but this is an autocyst as against biphragmal T. formosum, the type of the genus. Generic reallocation of T. plenum n. sp. may therefore be necessary when appropriate."
In view of the above opinion (Islam, 1983b, p. 90) it is apparent that cysts with two different types of wall structures (autocyst and biphragmal cyst) should be accomodated in two different genera. A new genus Jainiella is therefore erected to receive the single walled cysts (autocyst). Accordingly the genus Trivalvadinium is emended herein excluding the autocyst.
Trivalvadinium plenum Islam 1983b (p. 90; pl. 4, figs 4-6) having autocyst is thus transferred to the new genus.
Jainiella plena (Islam) comb. nov. = Triualvadinium plenum Islam 1983b, p. 90; pI. 4, figs 4-6; Palynology 7 : 71-92.