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Nannotax3 - ntax_main - Blackites Nannotax3 - ntax_main - Blackites

Blackites

Classification: ntax_main -> Syracosphaerales -> Rhabdosphaeraceae -> Blackites
Sister taxa: Acanthoica, Algirosphaera, Blackites, Cyrtosphaera, Discosphaera, Palusphaera, Rhabdosphaera, Solisphaera

Daughter taxa (time control age-window is: 0-800Ma)		Granddaughter taxa
	B. morionum group Spine low, globular, height<2x width	Blackites atanii Blackites deflandrei Blackites hayi Blackites mericii Blackites morionum Blackites shafikii Blackites australiensis Blackites elongatus Blackites perfectus Blackites prolatus Blackites rothii
	B. clavus group Spine conical, tapering with maximum width near base	Blackites bipartitus Blackites clavus Blackites dupuisii Blackites gamai Blackites spiculiformis Blackites thiedei
	B. inflatus group Spine inflated with maximum width above base, many with conspicous bulge	Blackites aktulagayensis Blackites bullatus Blackites creber Blackites culter Blackites flammeus Blackites fustis Blackites gladius Blackites globosus Blackites herculesii Blackites inflatus Blackites kilwaensis Blackites ornatus Blackites piriformis Blackites praeinflatus Blackites pseudomorionum Blackites rotundus Blackites rugosus Blackites sextonii Blackites turritus Blackites virgatus
	B. spinosus group Spine tall with narrow central opening	Blackites inversus Blackites minusculus Blackites perlongus Blackites rectus Blackites singulus Blackites spinosus Blackites stilus Blackites subtilis Blackites tenuis Blackites tortilis Blackites trochos Blackites truncatus
	B. amplus group Spine absent or very small	Blackites amplus Blackites friedrichii Blackites furvus Blackites sp. - bases
	Blackites sp. Specimens which cannot be assigned to any established species

Taxonomy:

Citation: Blackites Hay & Towe 1962

Taxonomic rank: genus

Type species: Discolithus spinosus Deflandre & Fert, 1954 = Blackites spinosus (Deflandre & Fert, 1954) Hay & Towe, 1962

Taxonomic discussion:

Differentiated from Rhabdosphaera by the presence of a radial lath cycle, which is reduced in some species, but is present as a series of residual radial elements between the outer cycle and the lamellar cycle. Typically more than one radial lath cycle element to each rim element.

Synonyms:

Blackites * Hay & Towe 1962

Variants:

The taxonomy outlined here is based on that of Bown (2005), and is essentially LM based. Other authors, most notably Shafik (1989) have separated various genera based on SEM studies using differences in the number of cycles in the base and process. Aubry (1999) reviews this work in depth. At present this taxonomy is difficult to apply and further SEM study of well-preserved material is needed, hence all these forms are included here in Blackites. Most of these genera would fall within the Blackites morionum group as recognised here.

Naninfula * Perch-Nielsen 1968 [type N. deflandrei is now included in Blackites]
Cepekiella * Roth 1970
Discoturbella * Roth 1970
Pseudotriquetrorhabdulus * Wise & Constans 1976 [variant according to Bown & Newsam 2017]
Wiseorhabdus * Bukry 1981 [superfluous replacement name for Pseudotriquetrorhabdulus]
Amitha * Shafik 1989
Cruxia * Varol 1989
Notiocyrtolithus * Shafik 1989 [considered a synonym of Cepekiella by Aubry 1999]
Ommatolithus * Shafik 1989

Distinguishing features:
Parent taxon (Rhabdosphaeraceae): BCs planoliths with radial lath cycle and highly-variable axial structures. Often polymorphic and/or varimorphic
This taxon: Coccoliths process-bearing with complex base including outer rim, radial lath and lamellar cycles

Morphology:

Spine- or process-bearing coccoliths with a base formed of three components:
1) a bicyclic outer rim (as in other Rhabdosphaeraceae);
2) a radial lath cycle (often with two laths per rim unit);
3) multiple lamellar cycles with clockwise obliquity.
These three cycles are consistently present, the processes however have highly variable structure, including forms with multiple tiers of additional cycles.

Size:

Spine height varies very greatly, from about 4 to 30 µm (and forms without spines occur). Basal diameter seem to be much less variable, almost always being about 3-6 µm and with no significantly larger forms known.

Search data:

LITHS: planolith, elliptical, CA: ca_disjunct, grill, process,

Lith size: 4->30µm;

The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): at top of Oligocene Epoch (100% up, 23Ma, in Aquitanian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within NP9 zone (55.86-57.21Ma, base in Thanetian stage). Data source: Total of ranges of species in this database

Plot of occurrence data:

Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested.
See also: customisable plot Parent: Rhabdosphaeraceae

References:

Aubry, M. -P. (1999). Handbook of Cenozoic calcareous nannoplankton. Book 5: Heliolithae (Zygoliths and Rhabdoliths). Micropaleontology Press, American Museum of Natural History, New York. 1-368. 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

Bown, P. R. (2010). Calcareous nannofossils from the Paleocene/Eocene Thermal Maximum interval of southern Tanzania (TDP Site 14). Journal of Nannoplankton Research. 31(1): 11-38. gs O

Bukry, D. (1981b). Pacific coast coccolith stratigraphy between Point Conception and Cabo Orientes, Deep Sea Drilling Project Leg 63. Initial Reports of the Deep Sea Drilling Project. 63: 445-471. gs

Hay, W. W. & Towe, K. M. (1962a). Electron microscope examination of some coccoliths from Donzacq (France). Eclogae Geologicae Helvetiae. 55: 497-517. gs O

Perch-Nielsen, K. (1968). Naninfula, genre nouveau a nannofossiles calcaires du Tertiaire danois. Comptes rendus hebdomaire de l'Académie des sciences, Paris. 267: 2298-2300. gs

Roth, P. H. (1970). Oligocene calcareous nannoplankton biostratigraphy. Eclogae Geologicae Helvetiae. 63: 799-881. gs O

Shafik, S. (1989). Some new calcareous nannofossils from Upper Eocene and Lower Oligocene sediments in the Otway Basin, southeastern Australia. Alcheringa. 13: 69-83. gs

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

Wise, S. W. & Constans, R. E. (1976). Mid Eocene plankton correlations Northern Italy - Jamaica W.I. Transactions of the Gulf-Coast Association of Geological Societies. 26: 144-155. gs

Blackites compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 22-7-2026

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