Nannotax3 - ntax_main - Blackites gladius Nannotax3 - ntax_main - Blackites gladius

Blackites gladius


Classification: ntax_main -> Syracosphaerales -> Rhabdosphaeraceae -> Blackites -> B. inflatus group -> Blackites gladius
Sister taxa: B. aktulagayensis, B. bullatus, B. creber, B. culter, B. flammeus, B. fustis, B. gladius, B. globosus, B. herculesii, B. inflatus, B. kilwaensis, B. ornatus, B. piriformis, B. praeinflatus, B. pseudomorionum, B. rotundus, B. rugosus, B. sextonii, B. turritus, B. virgatus


Taxonomy:
Citation: Blackites gladius (Locker, 1967) Varol, 1989
Taxonomic rank: species
Basionym: Rhabdosphaera gladius Locker, 1967
Taxonomic discussion: Similar to B. creber but with a broader, more inflated spine. Blackites rotundus has similar morphology but has a more globose spine. The rim structure is distinctly different to other coccoliths with similar spine morphologies, such as Blackites bullatus.

Distinguishing features:
Parent taxon (B. inflatus group): Spine inflated with maximum width above base, many with conspicous bulge
This taxon: Rhabdoliths with hollow ampulliform spines with a prominent basal collar and narrow base, widening to a maximum around three quarters of the way up, then taper to a point; the upper half of the spines display a distinctive striated pattern. The basal coccoliths are broad, the spine width is usually around half the coccolith width.

Farinacci & Howe catalog pages:
R. gladius *

Search data:
LITHS: planolith, circular, elliptical, CA: ca_disjunct, grill, process,
Lith size: 6->12µm;
Data source notes: lith size (spine height) from OD & illustrated specimens
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Notes: The top of R. gladius was used to define the NP15/16 boundary, but Perch-Niesen (1985) remarked that it was "often absent and thus of little use". Bown (2005) records R. gladius as high as NNP17.
Last occurrence (top): at top of NP15 zone (100% up, 42.9Ma, in Lutetian stage). Data source: zonal marker (see Perch-Nielsen 1985) - but not very reliable
First occurrence (base): within NP14 zone (46.29-49.11Ma, base in Ypresian stage). Data source: Bown 2005

Plot of occurrence data:

References:

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

Bown, P. R. (2005d). Palaeogene calcareous nannofossils from the Kilwa and Lindi areas of coastal Tanzania (Tanzania Drilling Project 2003-4). Journal of Nannoplankton Research. 27(1): 21-95. gs O

Locker, S. (1967c). Neue, statigraphisch wichtige Coccolithophoriden (Flagellata) aus dem norddeutschen Alttertiar. Monatsberichte der Deutschen Akademie der Wissenschaften zu Berlin. 9(9-10): 758-769. gs

Self-Trail, J. (2011). Paleogene Calcareous Nannofossils of the South Dover Bridge core, Southern Maryland (USA). Journal of Nannoplankton Research. 32(1): 1-28. gs

Varol, O. (1989b). Eocene calcareous nannofossils from Sile (northwest Turkey). Revista Española de Micropaleontología. 21: 273-320. gs

Varol, O. (1998). Palaeogene. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 200-224. gs

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Blackites gladius compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 11-6-2026

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Comments (2)

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I am confused with the following description on the short diagnosis - "The coccoliths are broad, and the spine is usually around half the width with a prominent basal collar".

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-agreed that it is not clear, i will reword it.

all the best Jeremy