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Acrosphaera mercurius Lazarus, 1992

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Medium to small spherical shell covered with numerous small, round, irregular size pores, which are distributed irregularly, often overlapping, and thus form small arcuate cusps that partially subdivide the enlarged double pore. Edges of pores rounded, not rimmed or funnelled; surface of shell rough, with low, sharp arcuate ridges and crests, which do not form a regular form pattern. No spines. Shell wall of moderate thickness.

Placed in Acrosphaera because of the irregular pore distribution, absence of pore frames, internal shells, or spines, all characteristics of collosphaerids. However, this form, with its rough shell surface and unrimmed pores, is not very similar to other members of Acrosphaera, and the generic assignment is uncertain.
Lazarus 1992











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