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Prolixosphaeridium inequiornatum
Prolixosphaeridium inequiornatum Stover and Helby, 1987
Holotype: Stover and Helby, 1987, fig.18C-E
Locus typicus: Exmouth Plateau, W Australia
Stratum typicum: Hauterivian
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Prolixosphaeridium inequiornatum Stover and Helby, 1987c. According to Stover and Helby (1987, p.246), Prolixosphaeridium inequiornatum is elongate, ellipsoidal with very thin autophragm and ectophragm, clearly separated; space between them occupied by numerous closely space, rod-like features, ca 0.5 µm in diameter, imparting a granulate appearance to the wall in plan view. Small verrucae, coni and short spines present on the ectophragm. Spines about 3-5 µm, concentrated in the polar areas. Nonpolar areas may have coni and small verrucae 1.5µm or less in height. Archeopyle apical. Operculum sometimes adherent but often free. Size: specimens without opercula 68-92 µm long, 33-40 µm wide. Specimens with opercula are 4-8 µm longer.
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Original description: Stover and Helby, 1987, p. 246
Cysts proximate and elongate ellipsoidal. Autophragm and ectophragm each very thin (less than 0.5 µm), clearly separated; space between them occupied by numerous, closely spaced, rod-like features, approximately 0.5 µm in diameter, imparting a granulate appearance to the wall in plan view. Small verrucae, coni, and short spines present on the ectophragm. Spines, about 3-5 µm in length, concentrated on the polar areas; those on the apical end tending to be fractionally
larger than those on the antapical end. Nonpolar area may have coni and small verrucae 1.5 µm or less in height and less numerous than the spines. However, on some specimens relatively large areas between the spinate poles are free of coni or verrucae. Archeopyle apical, its principal suture zigzag; accessory sutures present; operculum usually released completely, but may be adherent. Except for the archeopyle, additional indications of paratabulation not evident. Specimens without opercula 68 (81) 92µm long, and 33 (36) 40µm wide. Specimens with opercula are 4-8µm longer; 17 specimens measured.
Affinities:
Stover and Helby, 1987, p. 246: Prolixosphaeridium inequiornatum differs from P. parvispinum (Deflandre) Davey et al. 1969 in having verrucae and coni in addition to short spines and in having the longer ornamentation features concentrated on the polar areas. Other species of Prolixosphaeridium are smaller than P. inequiornatum, or have longer spines (processes), or both. In our opinion, P. elongatum Jain 1977 (p.185, pl.4, figs 48, 49) is conspecific with P. parvispinum.
Holotype: Stover and Helby, 1987, fig.18C-E
Locus typicus: Exmouth Plateau, W Australia
Stratum typicum: Hauterivian
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Prolixosphaeridium inequiornatum Stover and Helby, 1987c. According to Stover and Helby (1987, p.246), Prolixosphaeridium inequiornatum is elongate, ellipsoidal with very thin autophragm and ectophragm, clearly separated; space between them occupied by numerous closely space, rod-like features, ca 0.5 µm in diameter, imparting a granulate appearance to the wall in plan view. Small verrucae, coni and short spines present on the ectophragm. Spines about 3-5 µm, concentrated in the polar areas. Nonpolar areas may have coni and small verrucae 1.5µm or less in height. Archeopyle apical. Operculum sometimes adherent but often free. Size: specimens without opercula 68-92 µm long, 33-40 µm wide. Specimens with opercula are 4-8 µm longer.
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Original description: Stover and Helby, 1987, p. 246
Cysts proximate and elongate ellipsoidal. Autophragm and ectophragm each very thin (less than 0.5 µm), clearly separated; space between them occupied by numerous, closely spaced, rod-like features, approximately 0.5 µm in diameter, imparting a granulate appearance to the wall in plan view. Small verrucae, coni, and short spines present on the ectophragm. Spines, about 3-5 µm in length, concentrated on the polar areas; those on the apical end tending to be fractionally
larger than those on the antapical end. Nonpolar area may have coni and small verrucae 1.5 µm or less in height and less numerous than the spines. However, on some specimens relatively large areas between the spinate poles are free of coni or verrucae. Archeopyle apical, its principal suture zigzag; accessory sutures present; operculum usually released completely, but may be adherent. Except for the archeopyle, additional indications of paratabulation not evident. Specimens without opercula 68 (81) 92µm long, and 33 (36) 40µm wide. Specimens with opercula are 4-8µm longer; 17 specimens measured.
Affinities:
Stover and Helby, 1987, p. 246: Prolixosphaeridium inequiornatum differs from P. parvispinum (Deflandre) Davey et al. 1969 in having verrucae and coni in addition to short spines and in having the longer ornamentation features concentrated on the polar areas. Other species of Prolixosphaeridium are smaller than P. inequiornatum, or have longer spines (processes), or both. In our opinion, P. elongatum Jain 1977 (p.185, pl.4, figs 48, 49) is conspecific with P. parvispinum.