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Stiphrosphaeridium anthophorum

Stiphrosphaeridium antophorum (Cookson and Eisenack, 1958) Lentin and Williams, 1985

NOW Stiphrosphaeridium. Originally Hystrichosphaeridium, subsequently Oligosphaeridium, thirdly Polystephanephorus, fourthly Hystrichosphaerina, fifthly (and now) Stiphrosphaeridium. This combination was not validly published in Davey (1982b, p.18,35) since that author did not give a reference for Cookson and Eisenack (1958).
Taxonomic junior synonym: Hystrichosphaerina schindewolfii, according to Davey (1979c, p.65) — however, Lentin and Williams (1981, p.150) retained Hystrichosphaerina schindewolfii.

Holotype: Cookson and Eisenack 1958, pl.11, fig.12
Locus typicus: Omatia, Papua
Stratum typicum: Aptian-Albian

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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999

Stiphrosphaeridium anthophorum (Cookson and Eisenack, 1958) Lentin and Williams, 1985. Stiphrosphaeridium anthophorum has a process formula which is probably 4', 6", 0c, 6"’, 1p, 1ps. It does not have cingular processes. The processes are solid with an entire, fenestrate distal margin. Size: holotype overall 210 µm, shell 70 µm, processes ca. 50 µm.
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Original description: Cookson and Eisenack, 1958, p. 43: Hystrichsphaeridium anthophorum
Shell sphaeroidal and provided with about 10-15 stalked tubular appendages with short and sometimes broad, and frequently show the longitudinal fibrils of which they are composed, gradually widen distally, frequently close to the shell, into deep broad terminal expansions with completely and irregularly reticulate walls and continuous smooth or finely serrated outer edges.
Dimensions: Holotype - Shell 70 µm, overall 210 µm, appendages c.50 µm.

Supplemental description: Davey, 1969, p.147: Oligosphaeridium anthophorum
The shell is subspherical; shell wall smooth to lightly granular. An apical archaeopyle is typically developed and possesses an angular margin. The processes are hollow, buccinate to infundibular, with the distal flared portion perforate. Distally the margins of the processes are usually entire, but may bear one or two small spines. A complete specimen possesses 18 processes, reflecting a tabulation characteristic of this genus. The processes are all of equal size except for the first postcingular (1''') and the posterior intercalary (1p) which are often reduced. Dimensions: Range of observed specimens: diameter of central body 38(46.3)57 µm, maximum length of processes 18(34.1)43 µm. Number of specimens measured, 8.

Affinities:
Cookson and Eisenack, 1958, p. 43: Hystrichosphaeridium anthophorum is morphologically close to H. pulcherrimum and H. dyctioplocus. It differs from H. pulcherrimum in the more extensive reticulation of the appendages and the entire edge of the terminal expansion, and from H. dyctioplocus in the shorter and somewhat broader appendages and the wider mesh and continuous margin of the teminal expansions.
Brideaux, 1971, p.89: Oligosphaeridium anthophorum is characterized by flaring fenestrate or foveolate processes with entire open margins. The closely related form, O. pulcherrimum (Deflandre and Cookson) Davey and Williams 1966 possesses flaring fenestrate processes but without entire apices. O. dictyophorum (Deflandre and Cookson) Davey and Williams 1969, p.5 appears to differ from these two species in having thin, solid-walled columns and wide-meshed, strongly expanded columns.
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