Nannotax Enabling nannofossil research

Description: Elongate nannoliths formed of three blades. Entire nannolith formed of a single calcite crystal, but with variable c-axis orientation, see discussion of Family Triquetrorhabdulaceae.

Remarks: The genus contains two discrete sets of species

• T. carinatus group , with c-axis parallel to length and so always strongly birefringent, with length-fast orientation
• T. rugosus group , with c-axis perpendicular to length, show low biefringence in most common orientation, with length-slow orientation

Type species: T. carinatus Martini 1965

Range: NP24-NN12