Zygodiscus segmentatus
Set number: 1971
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Holotype in the mobile mount
Set number: 1970
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Set number: 1969
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Set number: 1968
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Set number: 1967
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Set number: 1966
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Set number: 1965
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Set number: 1964
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Set number: 1972
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Zygodiscus segmentatus Varol, 2025a
This species is characterised by a narrow, dextrally imbricated outer wall, a relatively wide tangential inner wall, and a multi-segmented, hexagonal diagonal disjunct bar that completely closes the central area. It has a distinct appearance in side view, with the central structure resembling a goblet.
From the Latin segmentatus, meaning segmented , referring to its segmented diagonal bar
Length = 8.24 μm; Width = 5-20 μm; Height = 3.87 μm (all measured in XPL).
Optical Properties: The outer wall remains in constant extinction, while the inner wall displays first-order white to yellow interference colours, with dextrogyre inclined extinction lines and length-fast (−) elongation on the distal side. The diagonal bar exhibits first-order whitish-grey interference colours with length-slow (+) elongation on the distal side. The goblet-like central structure shows length-fast (−) elongation, while the wall displays length-slow (+) elongation in the side view.
Varol, O. 2025a. A practical guide to optical studies of calcareous nannofossils. Grzybowski Foundation Special Publication. 29: 1-222
Holotype
Zygodiscus segmentatus
Varol, 2025a
Late Paleocene
DSDP Leg 39, Sites 354, Ceará Rise, North Atlantic Ocean