Cruciellipsis


Classification: Mesozoic -> Podorhabdales -> Cretarhabdaceae -> Cruciellipsis
Sister taxa: Speetonia, Cruciellipsis, Flabellites, Grantarhabdus, Helenea, Cretarhabdus, Retecapsa, Pickelhaube, Miravetesina,

Distinguishing features: Cretarhabdids with relatively broad shields; central area spanned by a broad axial cross, with strong medial extinction lines.


Daughter taxa: (blue => in age window 0-800Ma) Granddaughter taxa
Large (8-12 µm) Cretarhabdids with relatively broad shields and a central area spanned by tapering, broad, axial cross bars that are strongly birefringent with median extinction lines.

Specimens not identified to species level

Taxonomy:

Citation: Cruciellipsis Thierstein, 1971
Rank: Genus
Type species: Cruciellipsis cuvillieri (Manivit, 1966) Thierstein, 1971 emend. Wind and Cepek, 1979

Farinacci & Howe catalog pages: Cruciellipsis + *

Distinguishing features: Cretarhabdids with relatively broad shields; central area spanned by a broad axial cross, with strong medial extinction lines.


Morphology remarks: Cross bright when aligned with polariser, dark at 45° position, with gypsum plate cross shows opposite colours to adjacent rim  

Search data:
TagsLITHS: placolith, elliptical, CA: cross-axial, grill, process, R-UNITS: R-prominent, DETAILS: ca_disjunct, rim-unicyclic,
MetricsLith size: 8->16┬Ám;
Sources: size range of included species
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 Hauterivian Stage (100% up, 130.8Ma, in Hauterivian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Berriasian Stage (0% up, 145Ma, in Berriasian stage). Data source: Total of range of species in this database

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 :: ::

Thierstein, H. R. (1971). Tentative Lower Cretaceous Calcareous Nannoplankton Zonation. Eclogae Geologicae Helvetiae. 64: 459-488. gs :: view :: open

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 :: view :: open


nannotaxlogo400px

Cruciellipsis compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 7-8-2020

Taxon Search:
Advanced Search

Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=10327 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