Lucianorhabdus


Classification: Mesozoic -> Holococcoliths -> Common genera -> Lucianorhabdus
Sister taxa: Calculites, Lucianorhabdus, Orastrum, Owenia,

Distinguishing features: Holococcoliths with a proximal plate of four blocks and tall, hollow spines, which are often ridged or pitted and may be bulbous or curved.


Daughter taxa: (blue => in age window 0-800Ma)
cayeuxi and variants
Typical Lucianorhabdusspecies, base usually slightly wider than process
Lucianorhabdus with abruptly-curved, ridged, process
Lucianorhabduswith base wider than process, may end in plug
Lucianorhabdus with process wider than base, maximum width in lower half of the stem.
Lucianorhabdus with base wider than process
Lucianorhabduswith base wider than process, ends in crown-like plug
Lucianorhabdus with process of similar initial width to basal disk; shows bright longitudinal band in LM.
conical species
Small (4-6 µm) Lucianorhabdus with short conical, bluntly-terminated process. 


Medium sized (5-8 µm) Lucianorhabdus with short conical, pojnted process and thin baseplate
Medium sized (6-10 µm) Lucianorhabdus with long, tapering process
distinctive species
Lucianorhabdus with frondose, tree-like, process
Lucianorhabdus with cubic base and curved ridged process
Medium sized (5-6 µm) Lucianorhabdus with massive smooth process ending in bulb-like expansion
Lucianorhabdus with short bulb-like process with honeycomb-like ridges
Lucianorhabdus with elongate bulb-like process with honeycomb-like ridges
Specimens not identified to species level

Taxonomy:

Citation: Lucianorhabdus Deflandre, 1959
Rank: Genus
Type species: Lucianorhabdus cayeuxii Deflandre, 1959
Synonyms: Isocrystallithus Verbeek 1976

Farinacci & Howe catalog pages: Lucianorhabdus * , Isocrystallithus *

Distinguishing features: Holococcoliths with a proximal plate of four blocks and tall, hollow spines, which are often ridged or pitted and may be bulbous or curved.


Morphology remarks: The base of the coccolith is surrounded by a narrow rim with radial c-axes, this is often clearly visible in side views.


Size: Often very large - L. cayeuxi is from 10 to 30 µm long with base about 5-7µm across. Most other species have similar size bases.

Search data:
TagsLITHS: holococcolith, asymmetric, elliptical, rod-shaped, cylindrical, hollow, CA: process, R-UNITS: R-prominent, DETAILS: ca_disjunct, rim-unicyclic,
MetricsLith size: 4->35µm;
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 Maastrichtian Stage (100% up, 66Ma, in Maastrichtian stage). Data source: Total of range of species in this database
First occurrence (base): in mid part of Valanginian Stage (54% up, 136.4Ma, in Valanginian 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

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

Deflandre, G. (1959). Sur les nannofossiles calcaires et leur systématique. Revue de Micropaléontologie. 2: 127-152. gs

Verbeek, J. W. (1976a). Upper Cretaceous calcareous nannoplankton from Ballon and Théligny in the type area of the Cenomanian stage (Sarthe, France). Proceedings of the Koninklijke Nederlandse Akademie van Wetenschappen. B79: 69-82. gs


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Lucianorhabdus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 23-2-2020

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Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=10610 Go to Archive.is to create a permanent copy of this page - citation notes



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