Nannotax3 - ntax_main - H. carteri group

Nannotax3 - ntax_main - H. carteri group Nannotax3 - ntax_main - H. carteri group

H. carteri group

Classification: ntax_main -> Zygodiscales -> Helicosphaeraceae -> Helicosphaera -> H. carteri group
Sister taxa: H. carteri group, H. walbersdorfensis group, H. ampliaperta group, H. recta group, H. lophota group, H. sp.

Daughter taxa (time control age-window is: 0-800Ma)		Granddaughter taxa
	Extant and Pliocene species
	Helicosphaera pavimentum Small to medium sized. Flange narrow without distinct wing. Central-area with two small in-line pores.
	Helicosphaera hyalina Like H. carteri but coccoliths with closed central area (i.e. no pores) and usually smaller; also blanket is confined to central area leaving a broader rim of exposed flange elements than in H. carteri.
	Helicosphaera carteri Medium to large size, flange ends in wing, two inline pores in central-area.
	Helicosphaera wallichii Like H. carteri but central-area with inclined pores.
	Helicosphaera princei Like H. carteri but with single long slit in central area
	Helicosphaera inversa Like H. carteri but with large pores separated by prominent conjunct sub-horizontal bar usually with inverse orientation.
	Helicosphaera sellii Like H. carteri but pores large. (Late Pliocene- Early Pleistocene)
	Oligocene - Early Miocene species with conjunct bar
	Helicosphaera ethologa Like H.carteri but older (NP23-24) - also slits in central area and wing less developed.
	Helicosphaera huangii two large pores in central area and flange truncated.
	Helicosphaera mediterranea Like H. carteri but with large pores
	Helicosphaera minima Small species (2.5-4.5 µm) with slit in the central area.
	Oligo-Miocene species with disjunct bar
	Helicosphaera intermedia Bar thin straight and inclined	Helicosphaera zeta
	Helicosphaera rhomba Bar broad straight and strongly inclined, almost fills central area
	Helicosphaera euphratis Bar broad straight and strongly inclined, fills central area
	Helicosphaera leesiae bar sigmoid, nearly horizontal
	Helicosphaera truempyi Like H. carteri but very large, central-area open, spanned by horizontal disjunct bar.

Taxonomy:

Citation: H. carteri group of Young (1998)

Taxonomic rank: species group

Distinguishing features:
Parent taxon (Helicosphaera): Coccoliths with helical flange; arranged spirally on the coccosphere
This taxon: Living and Neogene medium to large species (typically 7-11 microns) with flanges that end in distinct wings.

Farinacci & Howe catalog pages:

Morphology:

These are medium to large species (typically 7-11 microns) with flanges that end in distinct wings. They are the most common helicoliths in most samples, but vary markedly through the Neogene. Forms with disjunct (optically discontinuous) bars (H. euphratis & H. intermedia) dominate in the Early Miocene but are replaced progressively by forms with closed central areas or conjunct bars. The blankets on these are initially rather chaotic (H. granulata) but forms with well ordered blankets with two in-line pores (H. carteri) become more common through the Late Miocene. In the Pliocene, forms with large and/or oblique pores (H. sellii and H. wallichii) become common.

Size:

Predominantly medim to large species (coccoliths 8-12 µm), the main excpetions being modern H. pavimentum (coccoliths 4-6 µm) and H. hyalina (coccoliths 5-8 µm). At least on modern H. carteri coccosphere size increase predominantly occurs by incresing the number of coccoliths/langth of th coccosphere rather than by incresing the size of the coccoliths or diameter of the coccoosphere.

Phylogenetic relations

H. hyalina and H. wallichii have often been regarded as varieties of H. carteri (e.g. Jordan & Young 1990, Jordan & Green 1994, Cros & Fortuño 2002), since they are similar in size and coccospheres bearing more than one morphotype have been illustrated (e.g. Nishida 1979). However, culture observations and molecular genetic data indicates that they are probably distinct species (Sáez et al. 2003, Geisen et al. 2004).

Search data:

Lith size: 4->12µm; Coccosphere size: 9->25µm;

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

Geological Range:
Notes: Supraha & Henderiks (2020) provide extensive data on Helicosphaera assemblages and morphometry through the Miocene to Recent and demonstrate that they show significant size decrease during this interval.
Last occurrence (top): Extant. Data source: Total of ranges of the species in this database
First occurrence (base): within NP18 zone (36.97-37.32Ma, base in Priabonian 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: Helicosphaera

References:

Supraha, L. & Henderiks, J. (2020). A 15-million-year-long record of phenotypic evolution in the heavily calcified coccolithophore Helicosphaera and its biogeochemical implications. Biogeosciences. 17: 2955-2969. gs

Young, J. R. (1998). Neogene. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 225-265. gs

H. carteri group compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 11-4-2026

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=636 Go to Archive.is to create a permanent copy of this page - citation notes

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