Micula praemurus


Classification: Mesozoic -> Braarudosphaerales -> Polycyclolithaceae -> Micula -> Micula praemurus
Sister taxa: M. staurophora, M. adumbrata, M. concava, M. cubiformis, M. swastica, M. murus, M. prinsii, M. clypeata, M. praemurus, M. premolisilvae, M. sp.,

Distinguishing features: Flattened, circular, disk-like Micula composed of a single cycle of four elements joined along curving, S-shaped sutures. 


Taxonomy:

Citation: Micula praemurus (Bukry, 1973) Stradner & Steinmetz, 1984
Rank: Species
Basionym: Tetralithus praemurus Bukry, 1973

Farinacci & Howe catalog pages: Tetralithus praemurus *

Distinguishing features: Flattened, circular, disk-like Micula composed of a single cycle of four elements joined along curving, S-shaped sutures. 


Morphology remarks: Micula clypeata and Micula premolisilvae share a number of morphological features that distinguish them from other Micula species, and likely represent closely related forms. They have comparable crystallographic orientation to  other Micula species but are flatter and the chirality of the elements does not change with focal depth.

Despite the name, M. praemurus does not appear a likely candidate for the direct ancestor of M. murus.

Geological Range:
Last occurrence (top): at top of Maastrichtian Stage (100% up, 66Ma, in Maastrichtian stage). Data source: Lees & Bown 2005 - consistently present to end Cret
First occurrence (base): within Campanian Stage (72.05-83.64Ma, base in Campanian stage). Data source: Burnett 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: Micula praemurus, synonyms included - Micula praemurus; Tetralithus praemurus; space-time plot :: Samples map :: Parent: Micula

    References:

    Bukry, D. (1973d). Phytoplankton stratigraphy, Deep Sea Drilling Project Leg 20, Western Pacific Ocean. Initial Reports of the Deep Sea Drilling Project. 20: 307-317. gs

    Burnett, J. A. (1998). Upper Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 132-199. gs

    Stradner, H. & Steinmetz, J. (1984). Cretaceous calcareous nannofossils from the Angola Basin, Deep Sea Drilling Project Site 530. Initial Reports of the Deep Sea Drilling Project. 75: 565-649. gs


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    Micula praemurus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 22-8-2019

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    Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=10679 Go to Archive.is to create a permanent copy of this page - citation notes



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