Biscutum sp. A
Varol, in prep.
Jan 13, 2026
Final Epithet
Biscutum sp. A Varol, in prep.
Basionym
Bidiscus sp. A
Optical Properties
In plan view under XPL, the distal shield is in constant extinction because the optic axis (c-axis) is perpendicular to the microscope stage, whereas the proximal shield displays a white interference colour and exhibits length-fast (–) elongation. The segments of the proximal shield are clearly visible under XPL.
Remarks
The circular placolith has distal and proximal shields of equal size, each composed of approximately 12 segments. The tube cycle is indistinct under the light microscope and may be absent.