Discoaster micros


Classification: Coccolithophores -> Discoasterales -> Discoasteraceae -> Discoaster -> D. musicus group -> Discoaster micros
Sister taxa: D. sanmiguelensis, D. ulnatus, D. patulus, D. musicus, D. carneyi, D. virginianus, D. transitus, D. micros, D. arneyi, D. premicros,

Daughter taxa: variants - intergrading morphotypes with slightly different ranges (blue => in age window 0-800Ma)
Prominent central stem and well-developed central area depressions
Prominent central stem

Taxonomy:

Citation: Discoaster micros (Theodoridis 1984) Kaenel and Villa 1996
Rank: Species
Basionym: Eu-discoaster micros (Theodoridis 1984)
Variants: de Kaenel et al. (2017) separate three forms - D. micros, D. stellimicros and D. catillomicros - based on development of central stem and depressions. They record them as having very similar FADs but that the form without a central stem (D. micros) persists into NN8-9. 
Notes & discussion: Discoaster transitus Peleo-Alampay et al. (1998) was considered a synonym of D. micros by Raffi et al. (1998) and this opino was previously followed on Nannotax. However, de Kaenel et al. (2017) note that D. micros has a large central area whereas D. transitus does not, so we follow them in separating the species.  

Distinguishing features: Small discoaster with short arms; bifurcations almost touching and thicker than the arms

Farinacci & Howe catalog pages: Eu-discoaster micros * , Discoaster transitus *

Search data:
TagsLITHS: nannolith-radiate, star-shaped, RIM: tips-bifurcate, free-rays-long,
CSPH: not known, V-UNITS: all, V-prominent, R-UNITS: none, DETAILS: 1ou,
MetricsLith size: 3->8µm; Segments: 6->6;
Sources: size from ODs & illustrated specs
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within NN9 zone (9.53-10.55Ma, top in Tortonian stage). Data source: de Kaenel et al. 2017
First occurrence (base): within NN6 zone (11.90-13.53Ma, base in Serravallian stage). Data source: de Kaenel et al. 2017

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: Discoaster micros, synonyms included - Discoaster micros;
  • space-time plot :: Samples map :: Parent: D. musicus group

    References:

    de Kaenel, E. & Villa, G. (1996). Oligocene-Miocene calcareous nannofossil biostratigraphy and paleoeecology from the Iberian Abyssal Plain. Proceedings of the Ocean Drilling Program, Scientific Results. 149: 79-145. gs :: view :: open

    de Kaenel, E., Bergen, J. A., Browning, E., Blair, S. A. & Boesiger, T. M. (2017). Uppermost Oligocene to Middle Miocene Discoaster and Catinaster taxonomy and stratigraphy in the circum North Atlantic Basin: Gulf of Mexico and ODP Leg 154. Journal of Nannoplankton Research. 37(2-3): 215-244. gs :: view :: open

    Okada, H. & Bukry, D. (1980). Supplementary modification and introduction of code numbers to the low-latitude coccolith biostratigraphic zonation (Bukry, 1973; 1975). Marine Micropaleontology. 5: 321-325. gs :: ::

    Peleo-Alampay, A., Bukry, D., Liu, L. & Young, J. R. (1998). Magnetobiostratigraphic calibration of datums from the late Miocene calcareous nannofossil genus Catinaster and discussion of its evolution. Journal of Micropalaeontology. 17(1): 71-85. gs :: view :: open

    Raffi, I., Backman, J. & Rio, D. (1998). Evolutionary trends of tropical calcareous nannofossils in the late Neogene. Marine Micropaleontology. 35(1): 17-41. gs :: ::

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


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    Discoaster micros compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 29-5-2020

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    Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=482 Go to Archive.is to create a permanent copy of this page - citation notes



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