Tanyosphaeridium boletus Davey, 1974

Holotype: Davey, 1974, pl.6, fig.7
Locus typicus: Speeton, England
Stratum typicum: Barremian

Original diagnosis: Davey, 1974, p.62
The cyst central body is elongate and bears many, relatively stiff, thin walled processes. The cyst wall is usually granular but may be smooth. The length of the processes measures between half and the total central body width. The processes are narrow, tubular and parallel sided; they expand slightly proximally and moie distally to give rise to a recurved and entire process margin. The cingulum may be distinctively devoid of processes. Some of the processes show a circular alignment parallel to the central body width. An apical archaeopyle is always developed, with the operculum sometimes remaining attached.
Dimensions Holotype Range
Central body length 43 µm 30 (38) 45 µm
Central body width 26 µm 22 (26) 30 µm
Process length 10-20 µm 14-21 µm (maximum)

Original description: Davey, 1974, p.62
The distal process extremities are in lateral view simply recurved, and in plan view are circular in outline with a central perforation. Occasionally this circular flange is broken and spines are seemingly present. The number of processes is normally between 50 and 70.

Affinities:
Davey, 1974, p.62: The distinctive process terminations distinguish T. boletus from the other members of this genus.