Nannotax3 - ntax_mesozoic - Tranolithus Nannotax3 - ntax_mesozoic - Tranolithus

Tranolithus


Classification: ntax_mesozoic -> Eiffellithales -> Chiastozygaceae -> Tranolithus
Sister taxa: Amphizygus, Archaeozygodiscus, Gorkaea, Placozygus, Reinhardtites, Tranolithus, Zeugrhabdotus ⟩⟨ Chiastozygus ⟩⟨ Staurolithites, Diadorhombus, Rhabdophidites ⟩⟨ Ahmuellerella, Bukrylithus, Diloma, Heteromarginatus, Misceomarginatus, Monomarginatus, Vacherauvillius ⟩⟨ Braloweria, Clepsilithus, Crepidolithus, Loxolithus, Neocrepidolithus, Tubirhabdus, C. - unidentified

Distinguishing features:
Parent taxon (Chiastozygaceae): Typical Eiffelithales - rim with well outer/upper clockwise-imbricate V-units and lower/inner R-units. Central area open or spanned by disjunct cross or bar supporting a spine.
This taxon: Murolith (loxolith) coccoliths with central area spanned by complex transverse structures principally constructed from two or four projections. Delicate lateral bars may also be present but are generally only seen in exceptional preservation.


Daughter taxa (time control age-window is: 0-800Ma)
Tranolithus bitraversus

Tranolithus gabalus
Small murolith (loxolith) with narrow rim and central area spanned by a transverse structure formed from two projections from the rim.
Tranolithus incus
Species with 4 blocky rim elements extending into central area and defining anvil-shaped opening. Low bridge
Tranolithus macleodiae
Projections are a pair of perforate angular blocks.
Tranolithus minimus

Tranolithus orionatus
Loxolith coccoliths with a transverse structure/bar composed of four lateral struts, a median granular component, and a central hollow spine base. In addition, the coccolith has a proximal grill composed of lateral bars.
Tranolithus praeorionatus
Medium sized (c. 5.0 µm) murolith coccolith with a transverse bar composed of four, short, triangular-shaped struts and a median granular section. The struts, which protrude from the inner rim edge, are conspicuous when the coccolith is orientated parallel to the polarising directions; the median part of the tranverse bar is only visible when the coccolith is rotated to 45°.
Tranolithus salillum

Tranolithus simplex
medium-sized with a narrow rim and broad central area spanned by a simple transverse bar. Unicyclic
Tranolithus sp.
Specimens not identified to species level

Taxonomy:

Citation: Tranolithus Stover, 1966
Taxonomic rank: genus
Type species: Tranolithus manifestus Stover, 1966. Probably conspecific with T exiguus and T. phacelosus, described by Stover, and T. orionatus described by Reinhardt, 1966. T. orionatus is probably the most widely used of these names.
Synonyms:

Farinacci & Howe catalog pages: Tranolithus + + + + + * , Pontilithus * , Barringtonella *

Distinguishing features:
Parent taxon (Chiastozygaceae): Typical Eiffelithales - rim with well outer/upper clockwise-imbricate V-units and lower/inner R-units. Central area open or spanned by disjunct cross or bar supporting a spine.
This taxon: Murolith (loxolith) coccoliths with central area spanned by complex transverse structures principally constructed from two or four projections. Delicate lateral bars may also be present but are generally only seen in exceptional preservation.


Morphology:

Defined by Stover (1966) for coccoliths similar to Zeugrhabdotus but which have central area bars, projections or ‘structures’ which are divided longitudinally, the structures having the same or similar crystallographic orientation as the adjacent rim. In practise Tranolithus has come to be used for murolith coccoliths which possess central structures composed of two or four blocks (e.g., Perch-Nielsen, 1985, p. 408; Bown & Young, 1997). The phylogenetic relationships between species grouped in Tranolithus is uncertain.

Search data:
LITHS: murolith, elliptical, CA: bar, process, ca_disjunct, CROSS-POLARS: V-prominent, rim-unicyclic,
Lith size: 2->10µm;
Data source notes: 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 Danian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within Pliensbachian Stage (184.20-192.90Ma, base in Pliensbachian stage). Data source: Total of ranges of species in this database

Plot of occurrence data:

References:

Black, M. (1972a). British Lower Cretaceous Coccoliths. I-Gault Clay (Part 1). Palaeontographical Society Monograph. 126: 1-48. gs

Bown, P. R. & Young, J. R. (1997). Mesozoic calcareous nannoplankton classification. Journal of Nannoplankton Research. 19(1): 21-36. gs

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

Gartner, S. (1968). Coccoliths and related calcareous nannofossils from Upper Cretaceous deposits of Texas and Arkansas. University of Kansas Paleontological Contributions, Articles. 48 (Protista 1): 1-56. gs O

Lambert, B. (1987). Nannofossiles calcaires de l'Albien supérieur et du Vraconnien du Cameroun méridional. Cahiers de Micropaléontologie. 2(2): 33-60. gs O

Perch-Nielsen, K. (1985). Mesozoic calcareous nannofossils. In, Bolli, H. M., Saunders, J. B. & Perch-Nielsen, K. (eds) Plankton Stratigraphy. Cambridge University Press, Cambridge (1): 329-426. gs

Reinhardt, P. (1966). Zur Taxonomie und Biostratigraphie des fossilen Nannoplanktons aus dem Malm, der Kreide und dem Alttertiär Mitteleuropas. Freiberger Forschungshefte. C196: 5-109. gs

Stover, L. E. (1966). Cretaceous coccoliths and associated nannofossils from France and the Netherlands. Micropaleontology. 12(2): 133-167. gs


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Tranolithus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 18-2-2025

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=11236 Go to Archive.is to create a permanent copy of this page - citation notes
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