Nannotax Enabling nannofossil research

Description: Symmetric 3-rayed variety of D. brouweri.

Remarks: Tan's description was extremely cursory but the concept is simple. These specimens occur throughout the range of D. brouweri, somewhat more consistently than D. asymmetricus. They do not increase in abundance in the mid-Pliocene, but do at the end of the Pliocene, just prior to the extinction of D. brouweri (Backman et al 1983, Backman 1986, 1987, Chapman & Chepstow-Lusty 1997).

Range: Common in upper part of NN18 (typically occurring at 1/5 to 1/2 the abundance of D. brouweri), occasional specimens NN9-21 (but rarely occurring at more than a few percent of abundance of D. brouweri)