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Hystrichosphaerina schindewolfii

Hystrichosphaerina schindewolfii Alberti, 1961

Originally (and now) Hystrichosphaerina, subsequently Systematophora, thirdly Polystephanephorus.
Taxonomic senior synonym: Hystrichosphaeridium (as Oligosphaeridium) anthophorum, according to Davey (1979c, p.65) - however, Lentin and Williams (1981, p.150) retained Hystrichosphaerina schindewolfii.
Taxonomic junior synonym: Perisseiasphaeridium eisenackii, according to Davey and Verdier (1974, p.640).
Yun, 1981, transferred this species to Polystephanephorus Sarjeant, 1961. Lentin and Williams, 1985, retained it in Hystrichosphaerina.

Holotype: Alberti, 1961, pl.10, figs.2-3; Eisenack and Kjellström, 1972, p.1009; Fensome et al., 1995, figs.2-3 - p.1765.
Locus typicus: Saxony, Germany
Stratum typicum: Late Barremian-Turonian
Translation Alberti, 1961: LPP

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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.

Hystrichosphaerina schindewolfii Alberti, 1961. Alberti (1961) noted that there are 2-6 radially arranged, vase- or beaker-like processes, which broaden distally and whose walls are perforated in mesh-like fashion.. The meshes are often elongate and extend commonly from the base to the outer margin of the “beaker”. This is almost entirely closed, often slightly toothed. There are a few long, thin processes, which are usually branched distally, in the equatorial zone. Size: central body diameter 58-70 µm, process length 22-39 µm.
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Original diagnosis: Alberti, 1961, p.39
Shell circular to oval. 12-16 vase-like, tubiform processes, distally widened and fenestrate. Fenestrae often elongated and may reach the base of the process. Processes distally closed, sometimes weakly dentate. A few, long, thin processes, which may be furcate distally, appear in the equatorial region. Ends of these processes not connected.

Remarks: L-type sexiform gonyaulacoid paratabulation as indicated by processes and process groups: 4', 6", 6c, 6''', 1'''', 1p, 5s. Cingular paraplates are each represented by two simple, distally bifurcating, tapering processes, often connected proximally or arising from a common base. Sulcal paraplates are also represented by simple, tapering (often distally blunt) intratabular processes: Z, Ii and Im plates are represented by a cluster of such processes. The remaining paraplates are represented by intratabular annulate process groups of varying diameter, each group connected distally by a continuous trabeculum. Evitt (1985: Fig. 4.4J, K, N) shows such process groups arising from a basal ridge. In this study the process group (or complex process) has been observed to consist of an outgrowth of the periphragm formed into a tube, the base of which is a continuous layer of periphragm - i. e. there is no direct connection between the endocyst and the environment via a pericoel. The proximal diameter of the process group is so reduced in some specimens as to give the impression of a distally fenestrate complex process. Periphragmal surface texture is pseudo-punctate.
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