Nannotax3 - ntax_mesozoic - Eprolithus antiquus

Eprolithus antiquus


Classification: ntax_mesozoic -> Braarudosphaerales -> Polycyclolithaceae -> Eprolithus -> Eprolithus antiquus
Sister taxa: E. rarus, E. moratus, E. octopetalus, E. floralis, E. apertior, E. antiquus, E. sp.

Distinguishing features:
Parent taxon (Eprolithus): Moderately tall, circular to stellate, multiradiate nannoliths with 5-9 petaloid wall-cycle elements surrounding a wide central area spanned by a median diaphragm. Typically H-shaped in side view.
This taxon: Circular eprolithid nannolith with narrow wall, wide diaphragm and relatively large central perforation. 


Taxonomy:

Citation: Eprolithus? antiquus Perch-Nielsen, 1979
Rank: Species
Synonyms: Lithastrinus antiquus

Farinacci & Howe catalog pages: E. antiquus *

Distinguishing features:
Parent taxon (Eprolithus): Moderately tall, circular to stellate, multiradiate nannoliths with 5-9 petaloid wall-cycle elements surrounding a wide central area spanned by a median diaphragm. Typically H-shaped in side view.
This taxon: Circular eprolithid nannolith with narrow wall, wide diaphragm and relatively large central perforation. 


Morphology:

The wall is constructed from small, brick-like elements, while the central diaphragm is composed of dextrally imbricate elements. The two wall cycles are of different height, with the diaphragm amedianly positioned. The number of elements in each cycle of the wall appears to be variable (10-12), but these are rudely-formed and difficult to count.
Differs from younger species of Eprolithus and Radiolithus in having a large perforation through the centre of the diaphragm and by a disjunct stratigraphic range (early Hauterivian, vs. early Aptian).

Size:

Search data:
TagsLITHS: nannolith-radiate, circular, cylindrical, CA: vacant, CROSS-POLARS: T-prominent,
MetricsLith size: 5->8µm; Segments: 10->12;
Data source notes: illustrated specimens
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 BC7 zone (100% up, 133.4Ma, in Hauterivian stage). Data source: Bown et al. 1998 - zonal marker
First occurrence (base): at base of BC7 zone (0% up, 133.9Ma, in Valanginian stage). Data source: Bown et al. 1998 - zonal marker

Plot of occurrence data:

References:

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

Perch-Nielsen, K. (1979d). Calcareous nannofossils from the Cretaceous between the North Sea and the Mediterranean. In, Weidmann, J. (ed.) Aspekte der Kreide Europas. International Union of Geological Sciences Series A. 6: 223-272. gs V O

Varol, O. (1992b). Taxonomic revision of the Polycyclolithaceae and its contribution to Cretaceous biostratigraphy. Newsletters on Stratigraphy. 27(93-127): -. gs


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Eprolithus antiquus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 29-5-2022

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10432 Go to Archive.is to create a permanent copy of this page - citation notes



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