Daughter taxa (time control age-window is: 0-800Ma)![]() | ||||
| Pappomonas borealis HOL BCs flat plates, with monolayer of crystallites. Tower coccoliths occur around coccosphere but higher at flagellar pole, centre of tube narrower; | ||||
| Trigonaspis melvillea BCs are only slightly raised above the baseplate. Tower coccoliths only at flagellar pole, with slender tube ending distally in a single distally directed triangular plate. | ||||
| Trigonaspis minutissima Similar to T. diskoensis but smaller (cells 2-3.5µm vs 5-6µm; CFCs 1-1.5µm vs 1.5-2.5µm high). Tower coccoliths only at flagellar pole | ||||
| Pappomonas garrisonii HOL BCs inconspicuous. Tower coccoliths occur around coccosphere but higher at flagellar pole. | ||||
| Trigonaspis sp. | ||||
Distinguishing features:
Parent taxon (open-tube): Holococcoliths with tube, open distally (or cover recessed)
This taxon: Holococcoliths formed of triangular crystallite groups (ca. 0.15 µm across), each composed of three (?hexagonal) sub-units.
Dimorphic CFCs tower-like, BCs simple disks.
See also: Pappomonas - alternate life-cycle phase of at least some species;
Search data:| LITHS: holococcolith, elliptical, cylindrical, hollow, CA: vacant, process, CROSS-POLARS: V-prominent, R-prominent, |
| Lith size: 0.5->1.5µm; Coccosphere size: 2->8µm; |
Geological Range:
Last occurrence (top): Extant. Data source: Total of ranges of the species in this database
First occurrence (base): within No known fossil record modern (0.00-0.00Ma, base in "Holocene" stage). Data source: Total of ranges of species in this database
Plot of occurrence data:
Thomsen, H. A. (1980). Two species of Trigonaspis gen. nov. (Prymnesiophyceae) from West Greenland. Phycologia. 19(3): 218-229. gs Thomsen, H. A., Ostergaard, J. B. & Hansen, L. E. (1991). Heteromorphic life histories in Arctic coccolithophorids (Prymnesiophyceae). Journal of Phycology. 27: 634-642. gs Thomsen, H. A., Ostergaard, J. B. & Cros, L. (2015). Ventimolina stellata gen. et sp. nov. (Haptophyta, Papposphaeraceae) from warm water regions. Acta Protozoologica. 54: 275-281. gs References:

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Trigonaspis compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 10-10-2026
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=1433 Go to Archive.is to create a permanent copy of this page - citation notes |
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