Neochiastozygus modestus

A medium-sized species of Neochiastozygus characterised by a wide outer wall and a narrow inner wall. A symmetrical diagonal cross with robust arms spans the central area. The crossbar forms an angle slightly less than 90° along the short axis and an obtuse angle along the long axis.

The outer wall remains in constant extinction, while the inner wall exhibits first-order white interference colours with dextrogyre inclined extinction lines and length-fast (−) elongation on the distal side. The crossbar appears dimer in this orientation, with its arms exhibiting length-fast (−) elongation.

In the side view, the narrow outer wall displays length-fast (−) elongation, whereas the broader and brighter inner wall exhibits length-slow (−) elongation.

Perch-Nielsen, K., 1971d. Neue Coccolithen aus dem Paläozän von Dänemark, der Bucht von Biskaya und dem Eozän der Labrador See. Bulletin of the Geological Society of Denmark 21, 51-66.