Nannotax3 - ntax_cenozoic - Umbellosphaera irregularis

Umbellosphaera irregularis

Classification: ntax_cenozoic -> Coccolith families inc sed -> Umbellosphaeraceae -> Umbellosphaera -> Umbellosphaera irregularis
Sister taxa: U. tenuis, U. irregularis, U. sp.


Citation: Umbellosphaera irregularis Paasche in Markali & Paasche, 1955
Rank: Species
Synonyms: Ellipsodiscoaster lidzii Boudreaux & Hay 1969 - according to Kleijne (1993), but illustrated specimens resemble U. tennis rather than U. irregularis

Distinguishing features:
Parent taxon (Umbellosphaera): Coccoliths trumpet-shaped
This taxon: Coccoliths concave outwards, without ridges on the distal surface

Farinacci & Howe catalog pages: U. irregularis *


Liths concave distally, giving the coccosphere an irregular profile (hence the name); distal surface smooth.
The concave outward shape of the coccliths gives the coccospheres a very irregular appearace in LM, hence the species name.


Ecology & Biogeography

Biology & life-cycles

Phylogenetic relations

Search data:
LITHS: placolith, asymmetric, elliptical, CA: ca_conjunct, plate, closed,
CSPH: equant, BC-dimorphic, CROSS-POLARS: rim-unicyclic, R-prominent,
Lith size: 1.4->10µm; Coccosphere size: 10->15µm; Liths per sphere: 14->30
Data source notes: lith size from Kleijne 1993; csph size from illustrated specs; lith numbers from Yang & Wei 2003, range inferred from single estimate
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): Extant. Data source: present in the plankton (Young et al. 2003)
First occurrence (base): within Quaternary Period (0.00-2.59Ma, base in Gelasian stage). Data source: Young (1998)

Plot of occurrence data:


Andruleit, H., Rogalla, U. & Staeger, S. (2005). Living coccolithophores recorded during the onset of upwelling conditions off Oman in the western Arabian Sea. Journal of Nannoplankton Research. 27(1): 1-14. gs V O

Boudreaux, J. E. & Hay, W. W. (1969). Calcareous nannoplankton and biostratigraphy of the late Pliocene-Pleistocene-Recent sediments in the Submarex cores. Revista Española de Micropaleontología. 1(3): 249-292. gs O

Heimdal, B. R. & Gaarder, K. R. (1981). Coccolithophorids from the northern part of the eastern central Atlantic II. Heterococcolithophorids. “Meteor” Forschungsergebnisse. 33: 37-69. gs

Kleijne, A. (1993b). Morphology, Taxonomy and distribution of extant coccolithophorids (Calcareous nannoplankton). Drukkerij FEBO B.V., Katwijk. 1-321. gs

Konno, S. & Jordan, R. W. (2006). Lagoon coccolithophorids from the Republic of Palau, NW Equatorial Pacific. Journal of Nannoplankton Research. 28(2): 95-110. gs O

Markali, J. & Paasche, E. (1955). On two species of Umbellosphaera, a new marine coccolithophorid genus. Nytt Magasin for Botanikk. 4: 95-100. gs

Reid, F. M. H. (1980). Coccolithophorids of the North Pacific Central Gyre with notes on their vertical and seasonal distribution. Micropaleontology. 26(2): 151-176. gs

Young, J. R. (1998). Neogene. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 225-265. gs V O

Young, J. R., Geisen, M., Cros, L., Kleijne, A., Probert, I. & Ostergaard, J. B. (2003). A guide to extant coccolithophore taxonomy. Journal of Nannoplankton Research, Special Issue. 1: 1-132. gs V O


Umbellosphaera irregularis compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 5-12-2022

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