Distinguishing features:
Parent taxon (R. reticulata group): Typically circular reticulofenestrids with relatively narrow circular central area with robust grill (clearly visible in lm).
This taxon: Similar to R. reticulata but >12µm
>12μm, broad tube-cycle and narrow central-area (Bown & Newsam 2017). Probaby simply a large morphotpe of R. reticulata according to Jones & Dunkley Jones (2020), but strigraphically useful, since it only occurs in the upper part of the range of R. reticulata.
| LITHS: placolith, circular, CA: ca_conjunct, grill, CSPH: equant, monomorphic, CROSS-POLARS: rim-unicyclic, R-prominent, |
| Lith size: 12->16µm; |
Geological Range:
Notes: Recorded by Fornaciari et al. (2010) as occurring consistently but at low occurrences. Jones & Dunkley Jones (2020) record the LADs of R. isabellae and R. reticulata as occurring later in the equatorial Indian Ocean than Fornaciari et al (2010) recorded from the Mediterranean.
Last occurrence (top): within chron C15n sub-Magnetochron (35.00-35.29Ma, top in Priabonian stage). Data source: Fornaciari et al. 2010
First occurrence (base): within chron C16n.2n sub-Magnetochron (36.05-36.70Ma, base in Priabonian stage). Data source: Fornaciari et al. 2010
Plot of occurrence data:
Bown, P. R. & Newsam, C. (2017). Calcareous nannofossils from the Eocene North Atlantic Ocean (IODP Expedition 342 Sites U1403–1411). Journal of Nannoplankton Research. 37(1): 25-60. gs O Fornaciari, E., Agnini, C., Catanzariti, R., Rio, D., Bolla, E. M. & Valvasoni, E. (2010a). Mid- Latitude calcareous nannofossil biostratigraphy and biochronology across the middle to late Eocene transition. Stratigraphy. 7(4): 229-264. gs Jones, A. P. & Dunkley Jones, T. (2020). Middle Eocene to Early Oligocene calcareous nannofossils from the Nanggulan Formation, Java, Indonesia. Journal of Nannoplankton Research. 38(1): 57-79. gs References:

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Reticulofenestra isabellae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 22-7-2026
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=1167 Go to Archive.is to create a permanent copy of this page - citation notes |
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