Chrysotila roscoffensis (P.A. Dangeard) R.A. Andersen, J.I. Kim, Tittley & H.S. Yoon (Figs. 10–14)

≡ Pleurochrysis roscoffensis (P.A. Dangeard) Fresnel & Billard (1991: 77)

A disc-shaped coccolith (placolith), that consists of a central vertical tube bounded on each side by shield, there are small nodes on the distal shield of the placolith and within the tube, extending into the central area; 2.46–2.85 × 1.74–1.98 µm in size.

This species was recorded from Zhetykol Lake and Aschisaysky Рond (see Table 2).

In this study, we found coccoliths in freshwater (Fig. 15), which we could not correlate with any of the described species. We described their as Hymenomonas uralensis sp. nov.