Chrysotila roscoffensis (P.A. Dangeard) R.A. Andersen, J.I. Kim, Tittley & H.S. Yoon, 2015

Ignatenko, Marina & Yatsenko-Stepanova, Tatyana, 2023, Coccolithophores in the algal flora from South Urals (Russia) with the description of a new Hymenomonas species, Phytotaxa 609 (1), pp. 55-64 : 60

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.

Figures

FIGURE 15. Hymenomonas uralensis sp. nov. (SEM). The arrows mark the preserved areas of the organic basal plate. Scale bars: 2 µm.

FIGURES 8–14. Species of Chrysotila from the reservoirs of the steppe zone of the South Urals (SEM). Figs. 8, 9: Chrysotila carterae. Figs. 10–14: C. roscoffensis. The arrows mark the different types of ornamentation of the distal shield of the placoliths belonging to the single cell. Scale bars: 8–10, 12–14–2 µm, 11–5 µm.