Clavatorella

NB TAXA WHICH ORIGINATE IN THE OLIGOCENE ARE NOT INCLUDED YET
Classification: pf_neogene -> Globigerinidae -> Clavatorella
Sister taxa: Beella, Globigerina, Globigerinella, Protentella, Globigerinoides, Globigerinoidesella, Globoturborotalita, Orbulina, Praeorbulina, Sphaeroidinella, Sphaeroidinellopsis, Trilobatus, Turborotalita, Catapsydrax, Clavatorella, Paragloborotalia, Orcadia,
Daughter taxa (blue => in age window 0-300Ma)

Specimens which cannot be assigned to established species

Taxonomy

Citation: Clavatorella Blow 1965
Rank: genus
Type species: Hastigerinella bermudezi
Taxonomic discussion:

Clavatorella has a low trochospiral test, which is evolute on the spiral side throughout. The chambers are subspherical or ovate in early stages, later becoming radially elongate and club shaped. This genus is distinguished from Globorotaloides by the presence of radially elongate and club-shaped· chambers in the later ontogenic development. Clavatorella differs from Protentella by its distinctly and strongly trochospiral test and umbilical-extraumbilical aperture.
Blow (1965) believed Clavatorella evolved from a globorotaliid ancestor and later (Blow, 1969) treated Clavatorella as a subgenus of Globorotalia. Lipps (1966) observed that the surface ultrastructure of Clavatorella bermudezi, the type species of Clavatorella, is similar to Protentella, and therefore placed Clavatorella in synonymy with Protentella. For the same reason, Srinivasan and Kennett (1975) treated Clavatorella as a subgenus of Protentella. Although the surface ultrastructures of Clavatorella (C. bermudezi) and Protentella (P. prolixa) are the same, we now believe that the difference in the degree of trochospiral coiling in later stages between these two genera justifies separation of Clavatorella from Protentella. The similarities in surface ultrastructure between Clavatorella and Protentella suggests a phylogenetic relationship between the two (Text Fig. 24) [Kennett & Srinvasan 1983]

Catalog entries: Clavatorella;

Type images:

Short diagnosis: low trochospiral test, later chanbers radially elongate and club shaped.

NB The short diagnoses are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus. They have initially been copied from the diagnostic characters/distinguishing features sections of the Eocene and Paleocene Atlases, they will be edited as the site is developed.

Description

Biogeography and Palaeobiology


Phylogenetic relations:

The genus Clavatorella developed from Globorotaloides hexagona in the Early Miocene and is ancestral to Protentella (Text Fig. 24). [Kennett & Srinivasan 1983]

Most likely ancestor: Globorotaloides - at confidence level 3 (out of 5). Data source: Kennett & Srinivasan 1983; .

Biostratigraphic distribution

Geological Range:
Last occurrence (top): within Zanclean Stage (3.60-5.33Ma, top in Zanclean stage). Data source: Total of range of species in this database
First occurrence (base): within Langhian Stage (13.82-15.97Ma, base in Langhian stage). Data source: Total of range of species in this database

Plot of occurrence data:

Primary source for this page: Kennett & Srinivisan 1983, p.218

References:

Blow, W.H., (1965). Clavatorella, a new genus of the Globorotaliidae. Micropaleontology, 11(3): 365-368.

Blow, W.H., (1969). Late middle Eocene to Recent planktonic foraminiferal biostratigraphy. In: Bronnimann, P. and Renz, H.H. (Editors), Proceedings of the First International Conference on Planktonic Microfossils, Geneva, 1967, Leiden, Netherlands, pp. 380-381.

Kennett, J.P. & Srinivasan, M.S., (1983). Neogene Planktonic Foraminifera. Hutchinson Ross Publishing Co., Stroudsburg, Pennsylvania, 1-265 pp.

Lipps 1966 [sorry, not in our bibliography yet]

Srinivasan, M.S. & Kennett, J.P., (1975). The status of Bolliella, Beella, Protentella and related planktonic foraminifera based on surface ultrastructure. Journal of Foraminiferal Research, 5(3): 155-165.


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Clavatorella compiled by the pforams@mikrotax project team viewed: 24-2-2018

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