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Surculosphaeridium granulatum
Surculosphaeridium? granulatum (W. Wetzel, 1952) Sarjeant, 1984
Originally Hystrichosphaeridium oligacanthum ssp. granulatum, subsequently Baltisphaeridium oligacanthum ssp. granulatum (an acritarch subspecies), thirdly Cleistosphaeridium? oligacanthum ssp. granulatum, fourthly (and now) Surculosphaeridium? granulatum. At the time of the transfer, Sarjeant, 1984 emended the diagnosis, raised the taxon to the species level and questionably included it in Surculosphaeridium.
Holotype: W. Wetzel, 1952, text-fig.25, Sarjeant, 1984, pl.5, figs.1-3; text-fig.8
Locus typicus: Kiel district, Germany
Stratum typicum: Danian
Translation W. Wetzel, 1952: Sarjeant, 1984
Original diagnosis: W. Wetzel, 1952, p. 404: Hystrichosphaeridium oligocanthum ssp. granulatum
Two specimens from flint boulder "Ak" reveal, by their dimensions and the relatively low number of processes, their relationship with H. oligacanthum but exhibit a feature not seen in other members of that species, namely a granulation of the capsule membrane. This granularity might be taken as a mere result of state of preservation were it not that, in related forms, no least suggestion of similar features was observed . . . The figured specimen shows on the upper surface a membrane defect, as is so commonly to be remarked in our plankton.
Emended diagnosis: Sarjeant, 1984, p. 136
Cyst chorate, spheroidal to broadly ovoidal. Processes of variable form but apparently always closed distally; they include capitate to bifurcate or trifurcate processes, with branches of variable lengths, typically undivided. One large process is present, apparently in mid dorsal situation, bifurcating at one-third height, with branches that themselves bifurcate or ramify. Length of processes is about 45 % of the cyst breadth. Phragma covered with granulations arranged in such fashion as to suggest an overall areolation. Archaeopyle essentially apical, but perhaps involving an adjacent dorsal intercalary paraplate.
Dimensions. Holotype (in polar view, distorted): maximum overall breadth 90 µm, maximum breadth of central body 60 µm.
Originally Hystrichosphaeridium oligacanthum ssp. granulatum, subsequently Baltisphaeridium oligacanthum ssp. granulatum (an acritarch subspecies), thirdly Cleistosphaeridium? oligacanthum ssp. granulatum, fourthly (and now) Surculosphaeridium? granulatum. At the time of the transfer, Sarjeant, 1984 emended the diagnosis, raised the taxon to the species level and questionably included it in Surculosphaeridium.
Holotype: W. Wetzel, 1952, text-fig.25, Sarjeant, 1984, pl.5, figs.1-3; text-fig.8
Locus typicus: Kiel district, Germany
Stratum typicum: Danian
Translation W. Wetzel, 1952: Sarjeant, 1984
Original diagnosis: W. Wetzel, 1952, p. 404: Hystrichosphaeridium oligocanthum ssp. granulatum
Two specimens from flint boulder "Ak" reveal, by their dimensions and the relatively low number of processes, their relationship with H. oligacanthum but exhibit a feature not seen in other members of that species, namely a granulation of the capsule membrane. This granularity might be taken as a mere result of state of preservation were it not that, in related forms, no least suggestion of similar features was observed . . . The figured specimen shows on the upper surface a membrane defect, as is so commonly to be remarked in our plankton.
Emended diagnosis: Sarjeant, 1984, p. 136
Cyst chorate, spheroidal to broadly ovoidal. Processes of variable form but apparently always closed distally; they include capitate to bifurcate or trifurcate processes, with branches of variable lengths, typically undivided. One large process is present, apparently in mid dorsal situation, bifurcating at one-third height, with branches that themselves bifurcate or ramify. Length of processes is about 45 % of the cyst breadth. Phragma covered with granulations arranged in such fashion as to suggest an overall areolation. Archaeopyle essentially apical, but perhaps involving an adjacent dorsal intercalary paraplate.
Dimensions. Holotype (in polar view, distorted): maximum overall breadth 90 µm, maximum breadth of central body 60 µm.