Nannotax Enabling nannofossil research

Description: Ceratoliths strongly birefringent, c-axis lies in plane of horseshoe, perpendicular to length.

Remarks:

Ceratolith morphology: The ceratoliths usually come to rest with the more ornamented side upward, in this orientation the right arm is usually shorter than the left arm, and more strongly curved, forming most of the arch. Both arms have keels on both surfaces. Those on the lower surface are more or less smooth, whereas those on the upper surface have a rodded structure. This rodding is most strongly developed on the right arm, and the rods are more nearly vertical on this arm. The asymmetry of structure makes the two surfaces easy to distinguish, in the light electron microscope and with care they can also be distinguished in the LM.

Life-cycle phases: The extant species C. cristatus also produces hoop-shaped coccoliths and "Neosphaera" planoliths. See species description for details.

Original description: