radiolaria - rads_cenozoic - Cypassis irregularis

Cypassis irregularis

Classification: rads_cenozoic -> Coccodiscidae -> Cypassis -> Cypassis irregularis
Sister taxa: C. irregularis, C. sp.


Citation: Cypassis irregularis Nigrini 1968
Rank: species
Basionym: Cypassis irregularis

Taxonomic discussion:
Nigrini 1968; Sanfilippo and Riedel, 1970

Catalog entries: Cypassis irregularis

Original description: Cortical twin shell spiny, slightly constricted equatorially, with subcircular to subangular pores having no definite arrangement; pores variable in size, tending to be smaller equatorially. Poles of twin shell not closed by a definite lattice, always spiny. In some specimens these spines support an irregular, usually incomplete, spongy meshwork. When complete, this meshwork forms an ellipsoidal shell around the cortical shell. Polar caps have not been observed.
Outer medullary shell ellipsoidal, connected to an inner, spherical medullary shell by radial beams; numerous radial beams also connect outer medullary shell to cortical twin shell at the equatorial constriction.

Length of cortical twin shell 118-1 84µm. Maximum breadth of cortical twin shell 63-99µm,
Remarks on original description: Rare in samples from along the coast of Central and South America; absent from all other samples examined (text-figure 4).


Biogeography and Palaeobiology

Biostratigraphic distribution

Geological Range:
Last occurrence (top): Extant Data source: Lazarus et al. 2015 - "R age group"
First occurrence (base): within Quaternary Period (0.00-2.59Ma, base in Gelasian stage). Data source: Lazarus et al. 2015 - "R age group"

Plot of occurrence data:


Nigrini, C. A. (1968). Radiolaria from eastern tropical Pacific sediments. Micropaleontology. 14(1): 51-63. gs

Sanfilippo, A. & Riedel, W. R. (1970). Post-Eocene "closed" theoperid radiolarians. Micropaleontology. 16(4): 446-462. gs


Cypassis irregularis compiled by the radiolaria@mikrotax project team viewed: 18-9-2021

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