Diagnosis

The suborder Zygodiscineae, consisting of discolith calcareous nannofossils, is characterised by single or double walls. The outer wall exhibits constant extinction under cross-polarised light (XPL) and comprises dextrally imbricated segments. The inner wall segments may be arranged in imbricated (radial or oblique), protolith, or tangential patterns, often inclined and displaying interference colours. The central area may contain structures such as axial or diagonal crosses or bars, typically lacking a distal process.

Remarks

Suborder of Eiffellitales

References

Varol, O. 2025a. A practical guide to optical studies of calcareous nannofossils. Grzybowski Foundation Special Publication. 29: 1-222