Distinguishing features: Broadly elliptical; central area width similar to shield width, spanned by conspicuous axial crossbars.
Farinacci & Howe catalog pages: Coccolithus hulliae *
Morphology remarks: Broadly elliptical coccolith with Ericsonia-like shield image and moderately wide central area (similar to shield width), spanned by conspicuous axial crossbars.
Remarks: In XPL the shields appear similar to Ericsonia (i.e. with broad, bright tube cycle). Although Ericsonia coccoliths are rarely and sporadically seen through the Eocene, these are usually small, circular forms and we consider it most likely that this species arose from a Coccolithus ancestor. Coccolithus hulliae appears to be stratigraphically restricted to Zones NP14–15 in the Exp. 342 material. This species may have been identified as Ericsonia insolita Perch-Nielsen, 1971 in Bralower & Mutterlose (1995) and documented as having a first appearance in Subzone NP14a.
Differentiation: Distinguised from other Coccolithus and Ericsonia by its distinctive shield image in XPL and moderately wide central area with conspicuous axial crossbars. [Bown & Newsam 2017]
Size: Holotype L = 8.4μm (Paratype L = 8.6μm).
|Tags||LITHS: placolith, elliptical, RIM: psh-bicyclic, CA: cross, cross-axial, |
CSPH: spherical, equant, monomorphic, V-UNITS: distal shield, px-tube, V-prominent, R-UNITS: c-str, ds-tube, prox shield, R-prominent, DETAILS: ca_disjunct, rim-bicyclic, isogyres oblique,
|Metrics||Lith size: 6->10µm; |
Last occurrence (top): within NP15b subzone (44.12-45.49Ma, top in Lutetian stage). Data source: Bown & Newsam 2017
First occurrence (base): within NP14b subzone (46.29-47.84Ma, base in Lutetian stage). Data source: Bown & Newsam 2017
Plot of occurrence data:
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