Owenia hillii


Classification: Mesozoic -> Holococcoliths -> Common genera -> Owenia -> Owenia hillii
Sister taxa: O. dispar, O. hillii, O. partitum, O. sp.,

Distinguishing features: Holococcolith with narrow birefringent rim with transverse protrusions into the central area. The central plate consists of two perforate blocks joined along a transverse suture. The single perforation in each block may be closed due to overgrowth. In side view the narrow rim continues proximally; the central structure comprises two lateral blocks but occasionally a smaller two-part internal block may be visible. A variably developed spine extends distally and may be closed by a distal plug. All these structures observed in side view, generally appear as crystallographically distinct blocks.


Taxonomy:

Citation: Owenia hillii Crux, 1991
Rank: Species
Notes & discussion: Lucianorhabdus compactus is a very similar species and was regarded by Bown et al. (1998) and Bown & Cooper (1998) as a senior synonym of O. hillii. Lees (2007) however regards them as a separate species.

Farinacci & Howe catalog pages: Owenia hilli *

Distinguishing features: Holococcolith with narrow birefringent rim with transverse protrusions into the central area. The central plate consists of two perforate blocks joined along a transverse suture. The single perforation in each block may be closed due to overgrowth. In side view the narrow rim continues proximally; the central structure comprises two lateral blocks but occasionally a smaller two-part internal block may be visible. A variably developed spine extends distally and may be closed by a distal plug. All these structures observed in side view, generally appear as crystallographically distinct blocks.


Morphology remarks: Owenia partitum is distinguished by the birefringent four-part bridge structure, observed when the coccolith axes are parallel with the polarising directions of the microscope; however, these blocks are not visible on rotation of the coccolith. In side view, the two species may be indistinguishable.

See also: Lucianorhabdus compactus - a similar taxon (or possibly a senior synonym);

Geological Range:
Last occurrence (top): within Late Cenomanian Substage (93.90-95.47Ma, top in Cenomanian stage). Data source: Kennedy et al. 2000
First occurrence (base): within NC9a subzone (107.59-109.94Ma, base in Albian stage). Data source: Kennedy et al. 2000

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: Owenia hillii, synonyms included - Owenia hilli; Owenia hillii;
  • space-time plot :: Samples map :: Parent: Owenia

    References:

    Bown, P. R. & Cooper, M. K. E. (1998). Jurassic. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 34-85. gs

    Bown, P. R. (2001). Calcareous nannofossils of the Gault, Upper Greensand and Glauconitic Marl (Middle Albian-Lower Cenomanian) from the BGS Selborne boreholes, Hampshire. Proceedings of the Geologists' Association. 112: 223-236. 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

    Crux, J. A. (1991a). Albian calcareous nannofossils from the Gault Clay of Munday’s Hill (Bedfordshire, England). Journal of Micropalaeontology. 10(203-221): -. gs

    Gale, A. S. et al. (2011). The uppermost Middle and Upper Albian succession at the Col de Palluel, Hautes-Alpes, France: An integrated study (ammonites, inoceramid bivalves, planktonic foraminifera, nannofossils, geochemistry, stable oxygen and carbon isotopes, cyclostratigraphy). Cretaceous Research. 32: 59-130. gs

    Jeremiah, J. (1996). A proposed Albian to Lower Cenomanian nannofossil biozonation for England and the North Sea Basin. Journal of Micropalaeontology. 15(97-129): -. gs

    Kennedy, W. J. et al. (2000). Integrated stratigraphy across the Aptian-Albian boundary in the Marnes Bleues, at the Col de Pre _-Guittard, Arnayon (Drome), and at Tartonne (Alpes-de-Haute-Provence), France: a candidate Global Boundary Stratotype Section and Boundary Point for the base of the Albian Stage. Cretaceous Research. 21: 591-720. gs

    Lees, J. A. (2007). New and rarely reported calcareous nannofossils from the Late Cretaceous of coastal Tanzania: outcrop samples and Tanzania Drilling Project Sites 5, 9 and 15. Journal of Nannoplankton Research. 29(1): 39-65. gs


    nannotaxlogo400px

    Owenia hillii compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 15-12-2019

    Taxon Search:
    Advanced Search

    Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=10842 Go to Archive.is to create a permanent copy of this page - citation notes



    Comments (0)

    No comments yet. Be the first!

    Add Comment

    * Required information
    1000
    Captcha Image
    Powered by Commentics