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Batiacasphaera angularis
Batiacasphaera angularis, Stevens and Helby, 1987
Holotype: Stevens and Helby, 1987, fig.2A-B
Locus typicus: Canning Basin, Australia
Stratum typicum: Early Berriasian
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Original description: [Stevens and Helby, 1987, p. 165]:
Description:
Cysts proximate, angularly subspherical to rounded ellipsoidal in shape, and subcircular to rounded diamond-shaped in outline, usually with a prominent folded equatorial bulge and a 1.5 µm long, rounded apical horn.
Autophragm variable in thickness from less than 1 µm to 2.5 µm, either smooth, finely or coarsely granulate, or irregularly foveolate.
Archeopyle apical, type [tA], principal suture zigzag with short accessory sutures. Operculum free but may be in place, commonly rounded but may have a small apical protuberance.
Paratabulation indicated by the archeopyle, and rarely by faint, low parasutural ridges (Fig.2C-F). Paratabulation gonyaulacacean, interpreted as 4", 6", Xc, 5""", 1p, 1"""" (Fig.3). Four apical paraplates in the most common gonyaulacoid pattern, (i.e. 1" only at the sulcal notch), indicated by the anterior margins of the precingular paraplates, 1"", 3"", 5"", 6" gabled, 2" and 4" with flat anterior margins. Paraplate 6 " is about half the width of
paraplate 5"". Middorsal position of the parasutural boundary between paraplates 2" and 3" above middorsal paraplate 4" ", contrasting with the more usual middorsal position of paraplate 3" above either paraplates 3""" or 4""".
Dimensions/Measurements:
Cyst length (dehisced) 52(67)84 µm, length increased by 12-18 µm when operculum present, cyst width 54(67)80 µm (21specimens).
Variability: Cyst size is fairly constant with the width approximately equal to the dehisced length. Cyst shape is variable due to the size of the equatorial bulge, the presence of a small apical horn, and the irregular folding of the cysts (Fig.2A,G).
Holotype: Stevens and Helby, 1987, fig.2A-B
Locus typicus: Canning Basin, Australia
Stratum typicum: Early Berriasian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Stevens and Helby, 1987, p. 165]:
Description:
Cysts proximate, angularly subspherical to rounded ellipsoidal in shape, and subcircular to rounded diamond-shaped in outline, usually with a prominent folded equatorial bulge and a 1.5 µm long, rounded apical horn.
Autophragm variable in thickness from less than 1 µm to 2.5 µm, either smooth, finely or coarsely granulate, or irregularly foveolate.
Archeopyle apical, type [tA], principal suture zigzag with short accessory sutures. Operculum free but may be in place, commonly rounded but may have a small apical protuberance.
Paratabulation indicated by the archeopyle, and rarely by faint, low parasutural ridges (Fig.2C-F). Paratabulation gonyaulacacean, interpreted as 4", 6", Xc, 5""", 1p, 1"""" (Fig.3). Four apical paraplates in the most common gonyaulacoid pattern, (i.e. 1" only at the sulcal notch), indicated by the anterior margins of the precingular paraplates, 1"", 3"", 5"", 6" gabled, 2" and 4" with flat anterior margins. Paraplate 6 " is about half the width of
paraplate 5"". Middorsal position of the parasutural boundary between paraplates 2" and 3" above middorsal paraplate 4" ", contrasting with the more usual middorsal position of paraplate 3" above either paraplates 3""" or 4""".
Dimensions/Measurements:
Cyst length (dehisced) 52(67)84 µm, length increased by 12-18 µm when operculum present, cyst width 54(67)80 µm (21specimens).
Variability: Cyst size is fairly constant with the width approximately equal to the dehisced length. Cyst shape is variable due to the size of the equatorial bulge, the presence of a small apical horn, and the irregular folding of the cysts (Fig.2A,G).