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Islandinium? cezare

Zonneveld, K.A.F. and Pospelova V. (2015). A determination key for modern dinoflagellate cysts. Palynology 39 (3), 387- 409.

 
 

ateral view
photographs Vera Pospelova

cross section

 

Field characteristics

Islandinium? cezare (de Vernal et al. 1989 ex de Vernal in Rochon et al. 1999) Radi et al., 2013.

Characteristics: 
Cyst with a spherical body and numerous apparently nontabular processes. Cyst wall is finely granulated. Processes are typically hollow at the basis with cavities extending usually to 1/4 to 1/2 of their length. Occasionally processes are solid along their entire length. Process bases is circular and about 1 µm across and separated from one another by about 2 to 3 µm. Process shafts are smooth, taper slightly and tips minutely expand to form platforms with recurved margins, appearing mushroom like in longitudinal section. Two morphotypes have been recognised in the Kara Sea with a second morphotype having solid processes with one or few barbs along the process shafts. Archeopyle probably apical.

Dimensions: Cyst body diameter: 29 - 45 µm; length of processes: 4 to 5.5 µm.
Motile affinity: unknown
Stratigraphic range: Pleistocene to recent

Comparison with other species:
The morphotype of the species that possesses solid spines only resembles most closely the species Islandinium brevispinosum. It differs by having less numerous processes with minutely tapered tips that are more or less regular distributed.