Maduradinium pentagonum Cookson and Eisenack, 1970

Holotype: Cookson and Eisenack, 1970, pl.10, fig.16
Paratype: Cookson and Eisenack, 1970
Locus typicus: Madura No. 1 Bore, Eucla Basin, Australia
Stratum typicum: Senonian

Original description: Cookson and Eisenack, 1970, p.150
Shell broader than long, approximately five-sided, divided by a wide, strongly outlined girdle into two approximately equal parts. The sides of the epitheca are slightly convex and, in the holotype, a short, centrally placed horn is present. The sides of the hypotheca slant inwards towards a slightly sloping antapex with a small prominence on either side, the right-hand one being the stronger. The girdle is wide, strongly outlined and its ends on the ventral surface are widely separated. The archeopyle is relatively large, six-sided and clearly outlined. The surface ornamentation consists of patches of dot-like thickenings of variable shape and size which are most strongly developed below the apex, near the lateral portions of the girdle and near the antapex.
Dimensions: Holotype: c. 85 μm long, c. 95 μm wide. Paratype: c. 81x100 μm. Range: length c. 80-103 μm, breadth c. 78-105 μm.