BIORBIS Strank, 1983

 

 

Type species: Biorbis duplex Strank, 1983; OD.

Biorbis Strank, 1983 (*3075), p. 441.

Test consisting of two concentric spheres or ellipsoids, the outer being up to 0.35 mm in diameter; wall calcareous, microgranular to granular, outer sphere with wall of up to 0.05 mm thickness, wall of each sphere differentiated into a dark microgranular outer layer that grades inward into a less dense and more granular region and then into a second dark and dense microgranular inner layer, no per­forations observed; no aperture known. L. Carboniferous (Dinantian); England.