Nannotax Enabling nannofossil research

Description: Optical orientation similar to T. rugosus (i.e. with c-axis perpendicular to length), but triangular-shaped and median blade broader than lateral blades. So usually lies in orientation showing high birefringence .

Remarks: 

Type species: Orthorhabdus serratus Bramlette and Wilcoxon, 1967

Range: NN2 to 6.