Sphenolithus heteromorphus


Classification: Coccolithophores -> Discoasterales -> Sphenolithaceae -> Sphenolithus -> S. heteromorphus group -> Sphenolithus heteromorphus
Sister taxa: S. heteromorphus, S. milanetti, S. preasii, S. belemnos, S. pseudoheteromorphus, S. conicus, S. calyculus, S. delphix, S. microdelphix, S. spinula,

Taxonomy:

Citation: Sphenolithus heteromorphus Deflandre 1953
Rank: Species
Notes & discussion: S. heteromorphus has a well developed quadrate base, in which the the upper part is nearly as large as the proximal part, which distinguishes it clearly from S. belemnos. Also the spine typically has a rather bulbous base in contrast to the straight-sided S. belemnos.

Distinguishing features: Apical spine very well-developed. Lateral elements nearly as large as proximal elements.

Farinacci & Howe catalog pages: Sphenolithus heteromorphus *


Size: Length 5-15 microns, varies considerably in all populations, possibly in part due to diagenetic overgrowth. Width usually c. 3-5 microns.

Search data:
TagsLITHS: nannolith-radiate, N: 3D-radiate, conical, circular, RIM: tiered, PROCESS: length-fast, monocrystalline, spine,
CSPH: not known, V-UNITS: spine, R-UNITS: lower-tier, middle-tier, DETAILS: isogyres radial,
MetricsLith size: 6->20µm;
Sources: lith height from illustrated specs
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Notes: Prone to reworking
Last occurrence (top): at top of NN5 zone (100% up, 13.5Ma, in Serravallian stage). Data source: zonal marker (see e.g. Young 1998)
First occurrence (base): at base of NN4 zone (0% up, 18Ma, in Burdigalian stage). Data source: FAD is very close to NN4 base , se e.g. Young (1998)

Plot of occurrence data:

  • Histogram - Neptune occurrence data from DSDP and ODP proceedings. Pale shading <50 samples in time bin. Interpret with caution & read these notes
  • Note to users in China - the diagram may not plot unless you use a VPN since I use google services on the website. If this is a problem please contact me 谢谢.
  • Taxon plotted: Sphenolithus heteromorphus, synonyms included - Sphenolithus heteromorphus; space-time plot :: Samples map :: Parent: S. heteromorphus group

    References:

    Bergen, J. A., de Kaenel, E., Blair, S. A., Boesiger, T. M. & Browning, E. (2017). Oligocene-Pliocene taxonomy and stratigraphy of the genus Sphenolithus in the circum North Atlantic Basin: Gulf of Mexico and ODP Leg 154. Journal of Nannoplankton Research. 37(2-3): 77-112. gs

    Bown, P. R. & Dunkley Jones, T. (2012). Calcareous nannofossils from the Paleogene equatorial Pacific (IODP Expedition 320 Sites U1331-1334). Journal of Nannoplankton Research. 32(2): 3-51. gs

    Deflandre, G. (1953). Hétérogénéité intrinsèque et pluralité des éleménts dans les coccolithes actuels et fossiles. Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences. Paris. 237: 1785-1787. gs

    Fornaciari, E. & Agnini, C. (2009). Taxonomic note: Sphenolithus pseudoheteromorphus, a new Miocene calcareous nannofossil species from the equatorial Indian Ocean. Journal of Nannoplankton Research. 30(2): 97-101. gs

    Maiorano, P. & Monechi, S. (1998). Revised correlations of early and middle Miocene calcareous nannofossil events and magnetostratigraphy from DSDP Site 563 (North Atlantic Ocean). Marine Micropaleontology. 35(235-255): -. gs

    Perch-Nielsen, K. (1972). Remarks on Late Cretaceous to Pleistocene coccoliths from the North Atlantic. Initial Reports of the Deep Sea Drilling Project. 12: 1003-1069. gs

    Perch-Nielsen, K. (1977). Albian to Pleistocene calcareous nannofossils from the Western South Atlantic, DSDP Leg 39. Initial Reports of the Deep Sea Drilling Project. 39: 699-823. gs

    Theodoridis, S. (1984). Calcareous nannofossil biostratigraphy of the Miocene and revision of the helicoliths and discoasters. Utrecht Micropaleontological Bulletin. 32: 1-271. gs

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


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    Sphenolithus heteromorphus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 18-9-2019

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    Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=1300 Go to Archive.is to create a permanent copy of this page - citation notes



    Comments (1)

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    Bryan C. Ladner
    Just wanted to point out that the correct spelling of S. heteromorphus is as indicated just now. There is no 'os' after morph, it is simply heteromorphus. I have a PDF copy of the original description by Deflandre (1953) if you need it to confirm my comment. Thanks, Bryan Ladner
    Gravatar
    Jeremy Young (NHM, UK)

    Thanks Brian
    You are quite right of course, this is something of a blind spot of mine. Anyway I have corrected it now (a moderately arkward process but easier than doing it in a non-database system).
    Jeremy

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