Conusphaera rothii


Classification: Mesozoic -> Nannoliths inc sedis -> Eoconusphaeraceae -> Conusphaera -> Conusphaera rothii
Sister taxa: C. mexicana, C. rothii, C. maledicto, C. sinespina, C. sp.,

Distinguishing features: Like C. mexicana but LM image shows spiralling pattern across the core, and curving extinction lines.


Daughter taxa: (blue => in age window 0-800Ma)
Small C. rothii - <4 µm
Large form of C. rothii - >4 µm

Taxonomy:

Citation: Conusphaera rothii (Thierstein, 1971) Jakubowski, 1986
Rank: Species
Basionym: Cretaturbella rothii Thierstein, 1971
Notes & discussion: Bergen 1998 argued that C. rothii is a preservational form of C. mexicana.

Farinacci & Howe catalog pages: Cretaturbella rothii *

Distinguishing features: Like C. mexicana but LM image shows spiralling pattern across the core, and curving extinction lines.


Morphology remarks: Tall tapering nannoliths with steeply sloping rim and central area filled with a core of radially arranged elements. Most commonly seen in side view. LM image shows spiralling pattern across the core, which is also crossed by curving extinction lines.

Geological Range:
Notes: Cited by Bown (1998) as an alternate marker for the base of zone BC6, following Mutterlose (1991), however he notes "this probably represents a first consistent occurrence in the boreal area as the species has been recorded sporadically from the Ryazanian (Crux pers. comm.)". Jakubowski (1987) also records occurrence throughout the Early Cretaceous. Varol & Bowman 2019 record the FO in the Tethyan area as in the Late Kimmeridgian
Last occurrence (top): within Early Aptian Substage (122.98-126.30Ma, top in Aptian stage). Data source: Bown et al. 1998
First occurrence (base): within Late Kimmeridgian Substage (152.06-154.73Ma, base in Kimmeridgian stage). Data source: Varol & Bowman 2019

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: Conusphaera rothii, synonyms included - Conusphaera rothii; Cretarhabdus rothii; Cretaturbella rothii;
  • space-time plot :: Samples map :: Parent: Conusphaera

    References:

    Bergen, J. A. (1998). Calcareous nannofossils from the lower Aptian historical stratotype at Cassis-La Bedoule (SE France). Géologie Méditerranéenne. 25(3-4): 227-255. gs

    Bown, P. R., Rutledge, D. C., Crux, J. A. & Gallagher, L. T. (1998). Early Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 86-131. gs

    Jakubowski, M. (1986). New calcareous nannofossil taxa from the Lower Cretaceous of the North Sea. INA Newsletter. 8: 38-42. gs

    Jakubowski, M. (1987). A proposed Lower Cretaceous calcareous nannofossil zonation scheme for the Moray Firth area of the North Sea. Abhandlungen der Geologischen Bundesanstalt. 39: 99-119. gs

    Mutterlose, J. (1991). Das Verteilungs- und Migrationsmuster des kalkigen Nannoplanktons in der borealen Unterkreide (Valangin-Apt) NW-Deutschlands. Palaeontographica B. 221: 27-152. gs

    Roth, P. H. & Thierstein, H. R. (1972). Calcareous nannoplankton: Leg 14 of the Deep Sea Drilling Project. Initial Reports of the Deep Sea Drilling Project. 12: 546-559. gs

    Thierstein, H. R. (1971). Tentative Lower Cretaceous Calcareous Nannoplankton Zonation. Eclogae Geologicae Helvetiae. 64: 459-488. gs

    Varol, O. & Bowman, A. R. (2019). Taxonomic revision of selected Late Jurassic (Tithonian) calcareous nannofossils and the application of mobile mounting. Neues Jahrbuch für Geologie und Paläontologie Abhandlungen. 291: 65-87. gs


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    Conusphaera rothii compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 24-10-2019

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    Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=10273 Go to Archive.is to create a permanent copy of this page - citation notes



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