Nannotax Enabling nannofossil research

Description: 5-rayed symmetric discoaster with broad bifurcations; rays planar and all show similar birefringence. The central area is not large but is distinct, there are usually low knobs on both the distal and proximal side.

Remarks: This species is only superficially similar to D. pentaradiatus. It is complanate, does not show any birefringence, has broad bifurcations; and is generally more robust. The last occurrence of D. prepentaradiatus is close to the first occurrence of D. pentaradiatus but there is no evidence that they are directly related. It is quite possible that D. prepentaradiatus evolved from D. bollii, whilst D. pentaradiatus was independently derived from D. exilis.

Original description: