Nannotax3 - ntax_mesozoic - Micula praemurus

Micula praemurus


Classification: ntax_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:
Parent taxon (Micula): Typically cubiform nannoliths usually formed from two superimposed and complexly-intergrown cycles of four pyramidal/blocky elements each
This taxon: 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: T. praemurus *

Distinguishing features:
Parent taxon (Micula): Typically cubiform nannoliths usually formed from two superimposed and complexly-intergrown cycles of four pyramidal/blocky elements each
This taxon: Flattened, circular, disk-like Micula composed of a single cycle of four elements joined along curving, S-shaped sutures. 


Morphology:

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.

Size:

Search data:
LITHS: nannolith-radiate, circular, quadrate, CA: closed,
Lith size: 5->8µm; Segments: 4->4;
Data source notes: illustrated specimens (Bukry quotes 5-10µm in description but he tends to quote very high maximum sizes)
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): at top of Maastrichtian Stage (100% up, 66Ma, in Danian 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:

References:

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

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

Lees, J. A. & Bown, P. R. (2005). Upper Cretaceous calcareous nannofossil biostratigraphy, ODP Leg 198 (Shatsky Rise, Northwest Pacific Ocean). Proceedings of the Ocean Drilling Program, Scientific Results. 198: 1-60. gs V O

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 O


nannotaxlogo400px

Micula praemurus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 25-9-2022

Taxon Search:
Advanced Search

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



Comments (0)

No comments yet on this page. Please do add comments if you spot any problems, or have information to share

Add Comment

* Required information
1000
Captcha Image
Powered by Commentics