Beella digitata

NB TAXA WHICH ORIGINATE IN THE OLIGOCENE ARE NOT INCLUDED YET
Classification: pf_neogene -> Globigerinidae -> Beella -> Beella digitata
Sister taxa: B. digitata, B. megastoma, B. praedigitata, B. sp.,

Taxonomy

Citation: Beella digitata (Brady, 1879)
Rank: species
Basionym: Globigerina digitata Brady, 1879

Catalog entries: Globigerina digitata;

Type images:

Short diagnosis: monospecific

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


Diagnostic characters: Medium to high trochospiral, chambers digitate

Aperture: : Interiomarginal umbilical-extraumbilical wide open arch bordered by a thick lip [Aze 2011, based on Kennett & Srinivasan 1983]

Coiling direction (in extant population): mixed


Wall type: Spinose; Irregularly cancellate [Aze 2011]

Test morphology: Test medium to high trochospiral, 4 to 5 rapidly increasing chambers in the final whorl, chambers-initially spherical, soon becoming ovate and finally radially elongate; sutures distinct, depressed; surface consisting of a fine, irregularly cancellate pattern of raised ridges surrounding the circular to subcircular pores; the discrete tubercles surrounding the pores represent spine bases (PI. 58, Fig. 1). Aperture interiomarginal, umbilical-extraumbilical, a wide open arch, bordered by a thick lip. [Kennett & Srinivasan 1983]

Size: >250µm

Biogeography and Palaeobiology


Geographic distribution: Tropical to temperate. [Kennett & Srinivasan 1983]

Isotope paleobiology: Aze et al. 2011 ecogroup 4 - Open ocean sub-thermocline. Based on very light ∂13C and very heavy ∂18O Cited sources (Aze et al. 2011 appendix S3): Coxall et al. (2007)

Phylogenetic relations: The height of the spire in B. digitata shows considerable variation with growth of the individual. There is a tendency toward streptospiral coiling in adult test, suggesting an affinity with Hastigerinella.
B. digitata developed from B. praedigitata, from which it differs in having the radially elongate chambers. [Kennett & Srinivasan 1983]

Molecular genetics: Genotypes recognised (data from PFR2 database, June 2017), one genotype only from 35 sequences; references: André et al. 2014; Weiner et al. 2014.

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

Biostratigraphic distribution

Geological Range:
Last occurrence (top): Extant Data source: present in the plankton (SCOR WG138)
First occurrence (base): within N22 zone (0.00-1.93Ma, base in Gelasian stage). Data source: Chaisson & Pearson (1997)

Plot of occurrence data:

Primary source for this page: Kennett & Srinivisan 1983, p.232

References:

André, A. & others, (2014). SSU rDNA Divergence in Planktonic Foraminifera: Molecular Taxonomy and Biogeographic Implications. PLoS One, 9: e104641.

Aze, T.; Ezard, T.H.G.; Purvis, A.; Coxall, H.K.; Stewart, D.R.M.; Wade, B.S. & Pearson, P.N.P., (2011). A phylogeny of Cenozoic macroperforate planktonic foraminifera from fossil data. Biological Reviews, 86: 900-927.

Brady, H.B., (1879). Notes on some of the reticularian Rhizopoda of the "Challenger" expedition. I.- On new or little known arenaceous types. Quarterly Journal of Microscopical Science, 19: 20-63.

Coxall, H.K.; Wilson, P.A.; Pearson, P.N. & Sexton, P.F., (2007). Iterative evolution of digitate planktonic foraminifera. Paleobiology, 33: 495-516.

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

Weiner, A.K.M.; Weinkauf, M.F.G.; Kurasawa, A.; Darling, K.F.; Kucera, M. & Grimm, G.W., (2014). Phylogeography of the tropical planktonic foraminifera lineage Globigerinella reveals isolation inconsistent with passive dispersal by ocean currents. PLoS One, 9: e92148.


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Beella digitata compiled by the pforams@mikrotax project team viewed: 23-11-2017

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