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Batioladinium fractum
Batioladinium fractum, (Mehrotra and Sarjeant, 1984), Lentin and Williams, 1985
Originally Imbatodinium, subsequently Batioladinium.
Tax. jr. synonym of Batioladinium (as Necrobroomea) micropodum (Eisenack and Cookson, 1960) Brideaux, 1975, according to Below, 1990.
Holotype: Mehrotra and Sarjeant, 1984, pl.1, fig.1; pl.2, fig.7
Locus typicus: Periyavadavadi Shallow well-1, Cauvery basin, South India
Stratum typicum: Aptian
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Original description as Imbatodinium fractum: [Mehrotra and Sarjeant, 1984, p. 217-218]:
Diagnosis:
Autoblast elongate having a small to moderately long apical horn and two reduced antapical horns, the latter often showing slight differences in length. Autophragm ornamented generally with faint, low-relief features or smooth. Ornamentation, where present, of finely reticulate or foveoreticulate type, muri low but seen as slight protuberances on cyst margin. Position of cingulum frequently indicated by inward flexure of autophragm along autoblast margin, coinciding with maximum cyst width and dividing cyst almost equally into epitract and hypotract. Paratabulation indicated by archeopyle only; latter of combination type. Operculum compound, involving all paraplates of preapical and apical series, at least one paraplate (probably 2a) of anterior intercalary series and paraplate of precingular series. Typically, at least three opercular pieces lost, one involving preapicals plus apicals, second involving intercalary paraplate(s) and third, a precingular paraplate (4"); however, preapicals in some instances form one or two separate opercular pieces.
(1) tA(1-4)a + I(2)a + P4a. See text-figures 1a-a", e; plate 1 figures 1-2; plate 2, figures 4, 7.
(2) tA(1-4) + (I(2) + P(4)) or (tA(1-4)a + 1(2) + P(4)). See text-figure 1b; plate 2, figures 2, 3.
(3) tA(1-4)a + I(2) + P(4)a. See text-figure 1c; plate 1, figure 4; plate 2, figure 5.
(4) tA(1-4)a + I(2) + P(4) or tA(1-4)a + (I(2)P(4))?. See text-figure 1d; plate 2, figure 1.
Affinities:
The compound operculum in Imbatodinium fractum is characteristic and distinguishes it from all other known species of the genus. However, when the style of operculum is better known in other species, this difference may disappear. The species will then remain distinguishable by its elongate autoblast, typically with a faint microreticulate or foveoreticulate ornamentation or sometimes laevigate, and also possibly by its development of a second opening dorsally on the hypotract. Imbatodinium micropodum (Eisenack and Cookson 1960) Dörhöfer and Davies 1980, a comparable species, differs from I. fractum in possessing a densely granular wall ornamentation.
Originally Imbatodinium, subsequently Batioladinium.
Tax. jr. synonym of Batioladinium (as Necrobroomea) micropodum (Eisenack and Cookson, 1960) Brideaux, 1975, according to Below, 1990.
Holotype: Mehrotra and Sarjeant, 1984, pl.1, fig.1; pl.2, fig.7
Locus typicus: Periyavadavadi Shallow well-1, Cauvery basin, South India
Stratum typicum: Aptian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description as Imbatodinium fractum: [Mehrotra and Sarjeant, 1984, p. 217-218]:
Diagnosis:
Autoblast elongate having a small to moderately long apical horn and two reduced antapical horns, the latter often showing slight differences in length. Autophragm ornamented generally with faint, low-relief features or smooth. Ornamentation, where present, of finely reticulate or foveoreticulate type, muri low but seen as slight protuberances on cyst margin. Position of cingulum frequently indicated by inward flexure of autophragm along autoblast margin, coinciding with maximum cyst width and dividing cyst almost equally into epitract and hypotract. Paratabulation indicated by archeopyle only; latter of combination type. Operculum compound, involving all paraplates of preapical and apical series, at least one paraplate (probably 2a) of anterior intercalary series and paraplate of precingular series. Typically, at least three opercular pieces lost, one involving preapicals plus apicals, second involving intercalary paraplate(s) and third, a precingular paraplate (4"); however, preapicals in some instances form one or two separate opercular pieces.
(1) tA(1-4)a + I(2)a + P4a. See text-figures 1a-a", e; plate 1 figures 1-2; plate 2, figures 4, 7.
(2) tA(1-4) + (I(2) + P(4)) or (tA(1-4)a + 1(2) + P(4)). See text-figure 1b; plate 2, figures 2, 3.
(3) tA(1-4)a + I(2) + P(4)a. See text-figure 1c; plate 1, figure 4; plate 2, figure 5.
(4) tA(1-4)a + I(2) + P(4) or tA(1-4)a + (I(2)P(4))?. See text-figure 1d; plate 2, figure 1.
Affinities:
The compound operculum in Imbatodinium fractum is characteristic and distinguishes it from all other known species of the genus. However, when the style of operculum is better known in other species, this difference may disappear. The species will then remain distinguishable by its elongate autoblast, typically with a faint microreticulate or foveoreticulate ornamentation or sometimes laevigate, and also possibly by its development of a second opening dorsally on the hypotract. Imbatodinium micropodum (Eisenack and Cookson 1960) Dörhöfer and Davies 1980, a comparable species, differs from I. fractum in possessing a densely granular wall ornamentation.