Distinguishing features:
Parent taxon (B. spinosus group): Spine tall with narrow central opening
This taxon: Long spine that tapers at both ends and displays a characteristic spiralling pattern in XPL. The spine has a narrow axial canal and is typically seen with no basal coccolith.
| LITHS: planolith, circular, rod-shaped, CA: ca_disjunct, grill, process, |
| Lith size: 9->16µm; Data source notes: lith size (spine height) from OD |
Geological Range:
Last occurrence (top): within NP19-20 zone (34.44-36.97Ma, top in Priabonian stage). Data source: Shamrock & Watkins 2012
First occurrence (base): within NP16 zone (40.40-42.87Ma, base in Lutetian stage). Data source: Bown & Dunkley Jones, 2006
Plot of occurrence data:
Bown, P. R. & Dunkley Jones, T. (2006). New Paleogene calcareous nannofossil taxa from coastal Tanzania: Tanzania Drilling Project Sites 11 to 14. Journal of Nannoplankton Research. 28(1): 17-34. gs 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 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 Shamrock, J. L. & Watkins, D. K. (2012). Eocene calcareous nannofossil biostratigraphy and community structure from Exmouth Plateau, Eastern Indian Ocean (ODP Site 762). Stratigraphy. 9(1): 1-11. gsReferences:

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Blackites tortilis compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 7-9-2026
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=131 Go to Archive.is to create a permanent copy of this page - citation notes |
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