Gephyrocapsa


Classification: Coccolithophores -> Isochrysidales -> Noelaerhabdaceae -> Gephyrocapsa
Sister taxa: Emiliania, Gephyrocapsa, Pseudoemiliania, Reticulofenestra, Noelaerhabdus, Bekelithella, Pyrocyclus,

Daughter taxa: (blue => in age window 0-800Ma) Granddaughter taxa
Extant/Late Pleistocene Species (organised by size)
Large species of Gephyrocapsa; bridge at low to intermediate angle to short axis; central area usually wide.

Intermediate size species of Gephyrocapsa; bridge at high angle to short axis; central area rather small.

Similar to G. ericsonii but larger, with teeth around tube, much higher bridge; consistently high angle (within 70-80° from short axis).

Very small species of Gephyrocapsa; bridge at high to intermediate angle to short axis; wide central area, thin bridge.



Extinct/Middle & Early Pleistocene species (organised by age)
Large to medium sized species of Gephyrocapsa; bridge at intermediate angle to short axis, and low (typically almost flush with the shield); central area almost closed.

Intermediate to large size species of Gephyrocapsa; bridge at low angle to short axis, central area broad.

Large Gephyrocapsa species; bridge at intermediate angle (40-60°) to the short axis, central opening size moderate to narrow.

Gephyrocapsa <3µm long - not usually identifiable to species level by light microscopy

Specimens which cannot be assigned to established species

Taxonomy:

Citation: Gephyrocapsa Kamptner, 1943
Rank: Genus
Type species: Gephyrocapsa oceanica Kamptner 1943
Notes & discussion: Species included: Gephyrocapsa taxonomy is notoriously confused but the following taxa are a useful starting set

Distinguishing features: Bridge across the central area

Farinacci & Howe catalog pages: Gephyrocapsa *


Morphology remarks: Coccoliths with structure similar to those of Emiliania and Reticulofenestra (see Young 1989 for discussion), but with a conjunct bridge, formed from inner tube-elements spanning central area; shields usually solid, i.e. without slits between the elements.

Evolution & Phylogeny: Gephyrocapsa and Reticulofenestra coccoliths only differ in the presence/absence of a bridge and at the time of origin of Gephyrocapsa the only other member of the Noelaerhabdaceae was Reticulofenestra. So, evoution from Reticulofenestra is very likely.

Biology & life-cycles: Diploid phase non-motile producing heterococcoliths. Haploid phase motile, non-calcifying.

Most likely ancestor: Reticulofenestra - at confidence level 3 (out of 5). Data source: Perch-Nielsen (1985), and others. .
Likely descendants: Emiliania;

Search data:
TagsLITHS: placolith, elliptical, CA: bridge, bridge-diagonal, grill,
CSPH: spherical, monomorphic, V-UNITS: none, R-UNITS: all, c-str, distal shield, prox shield, tube, DETAILS: ca_conjunct, isogyres kinked, isogyres oblique, rim-unicyclic,
MetricsLith size: 1.5->7µm; Coccosphere size: 3->10µm;
Sources:
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): Extant Data source: Total of range of species in this database
First occurrence (base): at base of Messinian Stage (0% up, 7.3Ma, in Messinian stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:

Bollmann, J. (1997). Morphology and biogeography of Gephyrocapsa coccoliths in Holocene sediments. Marine Micropaleontology. 29: 319-350. gs

Kamptner, E. (1943). Zur Revision der Coccolithineen-Spezies Pontosphaera huxleyi Lohm. Anzeiger der (Kaiserlichen) Akademie der Wissenschaften. Mathematische-Naturwissenschaftliche Klasse. Wien. 80: 73-49. gs

Perch-Nielsen, K. (1985a). Cenozoic calcareous nannofossils. In, Bolli, H. M. , Saunders, J. B. & Perch-Nielsen, K. (eds) Plankton Stratigraphy. Cambridge University Press, Cambridge 427-555. gs

Samtleben, C. (1980). Die Evolution der Coccolithophoriden-Gattung Gephyrocapsa nach Befunden im Atlantik. Paläontologische Zeitschrift. 54: 91-127. gs

Young, J. R. (1989). Observations on heterococcolith rim structure and its relationship to developmental processes. In, Crux, J. A. & Heck, S. E. v. (eds) Nannofossils and their applications. Ellis Horwood, Chichester 1-20. gs

Young, J. R., Geisen, M., Cros, L., Kleijne, A., Probert, I. & Ostergaard, J. B. (2003). A guide to extant coccolithophore taxonomy. Journal of Nannoplankton Research, Special Issue. 1: 1-132. gs


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Gephyrocapsa compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 17-9-2019

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Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=604 Go to Archive.is to create a permanent copy of this page - citation notes



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