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Spicadinium akidoton
Spicadinium akidoton Batten and Lister, 1988
Holotype: Batten and Lister, 1988, figs.5j,k
Locus typicus: Capel, Surrey, England
Stratum typicum: Hauterivian
Original diagnosis: Batten and Lister, 1988, p.357
Small skolochorate cyst, subpolygonal to ovoid in shape, epicyst smaller than hypocyst; maximum diameter of central body 30(38)53 x 25(31)41 µm (13 specimens). Phragma thin (c. 1 µm), probably an autophragm, granulate, giving rise to numerous, relatively long (c. 12-20 µm), narrow (1-2 µm), fairly rigid, tapered processes that terminate in a sharp point or hair-like filament which may be slightly recurved. They sometimes seem to be concentrated in intratabular and penitabular areas with a mid-dorsal pandasutural and mid-ventral sulcal area devoid of processes, but usually no clear alignment with paratabulation is evident. Archeopyle type uncertain but an excystment aperture is consistently indicated by apparently irregular rupturing of the epicyst.
Affinities:
Batten and Lister, 1988, p.358: The weak suggestion of paratabulation in a few specimens gives no clear indication of the botanical relationships of this species but its subpolygonal shape is consistent with a gonyaulacacean affinity. It is reminiscent of Taleisphaera hydra Duxbury, 1983 emend. Harding, 1986 in shape and in the granularity of the autophragm but it lacks the penitabular septa, clearly defined paratabulation, furcate process tips and 2P archeopyle of this taxon.
Holotype: Batten and Lister, 1988, figs.5j,k
Locus typicus: Capel, Surrey, England
Stratum typicum: Hauterivian
Original diagnosis: Batten and Lister, 1988, p.357
Small skolochorate cyst, subpolygonal to ovoid in shape, epicyst smaller than hypocyst; maximum diameter of central body 30(38)53 x 25(31)41 µm (13 specimens). Phragma thin (c. 1 µm), probably an autophragm, granulate, giving rise to numerous, relatively long (c. 12-20 µm), narrow (1-2 µm), fairly rigid, tapered processes that terminate in a sharp point or hair-like filament which may be slightly recurved. They sometimes seem to be concentrated in intratabular and penitabular areas with a mid-dorsal pandasutural and mid-ventral sulcal area devoid of processes, but usually no clear alignment with paratabulation is evident. Archeopyle type uncertain but an excystment aperture is consistently indicated by apparently irregular rupturing of the epicyst.
Affinities:
Batten and Lister, 1988, p.358: The weak suggestion of paratabulation in a few specimens gives no clear indication of the botanical relationships of this species but its subpolygonal shape is consistent with a gonyaulacacean affinity. It is reminiscent of Taleisphaera hydra Duxbury, 1983 emend. Harding, 1986 in shape and in the granularity of the autophragm but it lacks the penitabular septa, clearly defined paratabulation, furcate process tips and 2P archeopyle of this taxon.