Distinguishing features: Small holococcoliths with a rim, and central-area plate divided by a distinct, longitudinal suture.
Taxonomy:
Farinacci & Howe catalog pages: C. suturus *
Distinguishing features: Small holococcoliths with a rim, and central-area plate divided by a distinct, longitudinal suture.
Morphology: The relatively narrow rim is bright in PC, and at 45˚ in XPL. The rim and plate are close to crystallographically-continuous, and appear almost continuous at 0˚ in XPL; in this position two distinct rim-blocks appear at either end of the coccolith. The central-area is filled by a plate which is bisected by a longitudinal suture, best seen in PC. In XPL, the plate is brightest at 0˚ and dark at 45˚ but the suture is always visible.
Size: Length 3.8-4.0 microns
Tags | LITHS: holococcolith, elliptical, CA: ca_conjunct, pores, CROSS-POLARS: rim-unicyclic, R-prominent, |
Metrics | Lith size: 3->4µm; Segments: 1->1; Data source notes: original description |
Geological Range:
Last occurrence (top): within Late Hauterivian Substage (130.77-133.09Ma, top in Hauterivian stage). Data source: Bown & Concheyro, 2004
First occurrence (base): within Early Hauterivian Substage (133.09-133.88Ma, base in Hauterivian stage). Data source: Bown & Concheyro, 2004
Plot of occurrence data:
Bown, P. R. & Concheyro, A. (2004). Lower Cretaceous calcareous nannoplankton from the Neuquen Basin, Argentina. In, Villa, G., Lees, J. A. & Bown, P. R. (eds) Calcareous Nannofossil Palaeoecology and Palaeocenographic Reconstructions, Proceedings of the INA9 conference, Parma 2002. Marine Micropaleontology. 52(1-4): 51-84. gsReferences:
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Calculites suturus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 24-1-2021
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