Nannotax3 - ntax_mesozoic - Diloma primitiva Nannotax3 - ntax_mesozoic - Diloma primitiva

Diloma primitiva


Classification: ntax_mesozoic -> Eiffellithales -> Chiastozygaceae -> Diloma -> Diloma primitiva
Sister taxa: D. californica, D. galei, D. galiciense, D. placinum, D. primitiva, D. sp.

Distinguishing features:
Parent taxon (Diloma): Elliptical loxoliths with a rim that appears tricyclic, composed of inner and outer rim cycles and a proximal plate. The outer rim cycle and proximal plate are only weakly birefringent, while the blocky inner rim cycle is brightly birefringent. Central structures are variable but include cross bars, lateral bars and curving concentric bars.
This taxon: Medium-sized elliptical form with a relatively delicate rim that in LM appears to consist of three narrow cycles: the inner and outer cycles are weakly birefringent (grey) while the middle cycle is brightly birefringent (white). The complex central structure comprises axial cross bars, concentric bars and numerous lath-like radial bars.


Taxonomy:

Citation: Diloma primitiva (Worsley, 1971) Wind & Cepek, 1979
taxonomic rank: Species
Basionym: Arkhangelskiella primitiva Worsley, 1971

Farinacci & Howe catalog pages: A. primitiva *

Distinguishing features:
Parent taxon (Diloma): Elliptical loxoliths with a rim that appears tricyclic, composed of inner and outer rim cycles and a proximal plate. The outer rim cycle and proximal plate are only weakly birefringent, while the blocky inner rim cycle is brightly birefringent. Central structures are variable but include cross bars, lateral bars and curving concentric bars.
This taxon: Medium-sized elliptical form with a relatively delicate rim that in LM appears to consist of three narrow cycles: the inner and outer cycles are weakly birefringent (grey) while the middle cycle is brightly birefringent (white). The complex central structure comprises axial cross bars, concentric bars and numerous lath-like radial bars.

Search data:
LITHS: murolith, elliptical, CA: concentric-ring(s), cross-axial, ca_disjunct, grill, plate, process, CROSS-POLARS: rim-bicyclic, V-prominent, R-prominent,
Lith size: 7->8µm;
Data source notes: original description & illustrated specimens
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within Early Aptian Substage (118.70-121.40Ma, top in Aptian stage). Data source: Bown et al. 1998
First occurrence (base): within Valanginian Stage (132.60-137.70Ma, base in Valanginian stage). Data source: Bown et al. 1998

Plot of occurrence data:

References:

Applegate, J. L. & Bergen, J. A. (1988). Cretaceous calcareous nannofossil biostratigraphy of sediments recovered from the Galicia Margin, ODP Leg 103. Proceedings of the Ocean Drilling Program, Scientific Results. 103: 293-348. gs O

Bown, P. R. (2005c). Early to Mid-Cretaceous Calcareous Nannoplankton from the Northwest Pacific Ocean, Leg 198, Shatsky Rise. Proceedings of the Ocean Drilling Program, Scientific Results. 198: 1-82. gs O

Bown, P. R., Rutledge, D. C., Crux, J. A. & Gallagher, L. T. (1998). Lower Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 86-131. gs O

Wind, F. H. & Cepek, P. (1979). Lower Cretaceous calcareous nannoplankton from DSDP Hole 397A (northwest African Margin). Initial Reports of the Deep Sea Drilling Project. 47A: 221-235. gs

Worsley, T. R. (1971). Calcareous nannofossil zonation of Upper Jurassic and Lower Cretaceous sediments from the Western Atlantic. In, Farinacci, A. (ed.) Proceedings of the Second Planktonic Conference Roma 1970. Edizioni Tecnoscienza, Rome 2: 1301-1321. gs O


nannotaxlogo400px

Diloma primitiva compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 22-2-2024

Taxon Search:
Advanced Search

Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10383 Go to Archive.is to create a permanent copy of this page - citation notes
nannotaxlogo400px

Nannotax is being sponsored through 2024 by Woodside Energy and Shell USA


Add Comment

* Required information
Captcha Image
Powered by Commentics

Comments

No comments yet. Be the first!