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Exochosphaeridium pseudohystichodinium

Exochosphaeridium pseudohystrichodinium (Deflandre, 1937) Davey et al., 1969

Now Pervosphaeridium. Originally Hystrichosphaeridium, subsequently Baltisphaeridium, thirdly Exochosphaeridium?, fourthly (and now) Pervosphaeridium.
Tax. sr. synonym of Exochosphaeridium? palmatum (Detlandre and Courteville, 1939) Davey et al., 1969, according to Yun, 1981.
Questionable tax. sr. synonyrn of Exochosphaeridium muelleri Yun, 1981, according to Ziaja, 1989.
At the time of the transfer, Davey et al., 1969, questionably included this species in Exochosphaeridium.
Stover and Evitt, 1978, considered this to be a provisionally accepted species of Exochosphaeridium.
This combination was not validly published in Davey et al., 1966, since these authors did not fully reference the basionym.
Holotype: Deflandre 1937, pl.15, fig.3
Locus typicus: Paris Basin, France
Stratum typicum: Late Cretaceous

Supplemental description: Davey et al., 1969, p.16-17
Shell spherical to ovoidal; shell wall thick, with pitted surface. Processcs numerous, slightly fibrous, occasionally bifurcating medially, slender, broadening slightly proximally; distally truncated or terminated with small bifurcation. Cingular processes rarely aligned. Apical proccss sometimes branched and slightly larger than normal. Archaeopyle precingular, formed by loss of one or two plate areas.
Dimensions: Range of type material: shell length 49 to 54 Ám, shell width 38 to
45 Ám, overall length 80-90 Ám. Range of observed specimens: diameter of central
body 35(43.8)54 Ám, maximum length of processcs 13(16.8)21 Ám. Number of
specimens measured, 12.

Description: Davey et al., 1969, p.17
The shell wall is moderatcly thick (c. 1.5 Ám), pitted (never striated), and bears a large number of broad-based processes. All the proccsses appear to be basically the same except for the apical process which is typically branched and is usually larger than normal.
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