Classification: Coccolithophores -> Coccolithales -> Coccolithaceae -> Ericsonia
Sister taxa: Coccolithus, Bramletteius, Campylosphaera, Chiasmolithus, Coronocyclus, Cruciplacolithus, Ericsonia, Solidopons, Birkelundia, Clausicoccus, Craticullithus, Hughesius, Kilwalithus,

Daughter taxa: (blue => in age window 0-800Ma)
Forms with narrow central opening
very small (~3μm), circular with raised distal collar and tall proximal shield
medium to large, subcircular to circular with narrow central area
medium to large (~6–11μm), subcircular to circular; moderately broad upper-tube cycle and narrow central area;
Forms with wide central opening
small (<5μm), circular with relatively wide central area;
small (<5μm), circular with relatively wide central area spanned by cross bars
medium-sized (5–9μm), circular to subcircular with relatively wide central area
large (>9μm), circular with wide central area;
Specimens which cannot be assigned to any established species


Citation: Ericsonia Black, 1964
Rank: Genus
Type species: Ericsonia occidentalis Black, 1964
Notes & discussion: The generic name Ericsonia has been used for a wide range of circular and elliptical coccoliths that are now classified within ClausicoccusCoccolithus, Prinsius, Toweius and Reticulofenestra. The type species, E. occidentalis, is a large, broadly-elliptical, middle Eocene form which is probably a junior synonym of C. pelagicus. Nonetheless the set of taxa included here are normally placed in Ericsonia. So, this usage is followed here pending a revison of the taxonomy. 
The genus Diadelithus Aubry & Bord (2009) probably should be used instead, since the type species is E. robusta. However, as described Diadelithus includes a rather different set of species and so the genus would need to be emended, and new combinations proposed [JRY 2016]

Distinguishing features: Coccolithus-like coccoliths that are typically circular and have broad upper tube elements that dominate the distal shield. The dominance of the R-unit cycle results in a bright LM XPL image that is distinct from Coccolithus.

Farinacci & Howe catalog pages: Ericsonia + * , Diadelithus *

Search data:
TagsLITHS: placolith, circular, RIM: inner-tube-broad, psh-bicyclic, CA: vacant,
CSPH: spherical, equant, monomorphic, V-UNITS: distal shield, px-tube, V-prominent, R-UNITS: ds-tube, prox shield, R-prominent, DETAILS: rim-bicyclic, isogyres oblique,
MetricsLith size: 5->12µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): in lower part of Rupelian Stage (17% up, 32.9Ma, in Rupelian stage). Data source: Total of range of species in this database
First occurrence (base): in lower part of Danian Stage (42% up, 64.2Ma, in Danian stage). Data source: Total of range of species in this database

Plot of occurrence data:


Aubry, M. -P. & Bord, D. (2009). Reshuffling the cards in the photic zone at the Eocene/Oligocene boundary. In, Koeberl, C. & Montanari, A. (eds) The Late Eocene Earth—Hothouse, Icehouse, and Impacts. Geological Society of America, Special Papers. 452: 279-301. gs :: ::

Black, M. (1964). Cretaceous and Tertiary coccoliths from Atlantic seamounts. Palaeontology. 7: 306-316. gs :: view :: open


Ericsonia compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 3-8-2020

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