Cyclagelosphaera paucisegmenta
Set number: 1752
-
1
-
2
-
3
-
4
-
5
-
6
-
7
10µm
Holotype
Cyclagelosphaera paucisegmenta Varol & Bowman, 2019
Large (8.0–12.0 μm) circular species of Cyclagelosphaera, typically having 20 wide and easily discernible segments in its distal shield.
From Latin pauci segmenta, few segments, referring to its low number of segments.
Diameter = 9.56 μm; length (central area) = 3.20 μm; width (central area) = 1.84 μm.
Cyclagelosphaera paucisegmenta has a very narrow, elliptical and closed central area, which is difficult to detect in crossed polarised light (XPL). The tube cycle is also not obvious. The proximal shield is smaller than the distal shield and easily noticeable by its first-order yellow birefringence colour in XPL. Its periphery is often irregular and produces a false impression of a subcircular outline.
Cyclagelosphaera paucisegmenta is easily differentiated from the other species of Cyclagelosphaera by having wide, discernible segments in its distal shield and an
indistinct elliptical central area.
Varol, O. & Bowman, A.R. 2019. Taxonomic revision of selected Late Jurassic (Tithonian) calcareous nannofossils and the application of mobile mounting. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 291/1 (2019): 1–23
Holotype
Cyclagelosphaera paucisegmenta
Varol & Bowman, 2019
Early Berriasian
DSDP Leg 76, Site 534, Blake-Bahama Basin, Atlantic Ocean