Dentoglobigerina galavisi


Classification: pf_cenozoic -> muricate non-spinose -> Globoquadrinidae -> Dentoglobigerina -> Dentoglobigerina galavisi
Sister taxa: D. galavisi, D. juxtabinaiensis, D. prasaepis, D. pseudovenezuelana, D. taci, D. tapuriensis, D. tripartita, D. sp.,

Taxonomy

Citation: Dentoglobigerina galavisi (Bermudez 1961)
Rank: Species
Basionym: Globigerina galavisi
Synonyms:
Taxonomic discussion: Blow (1979) treated the holotype of Dentoglobigerina galavisi as separate from the “central type” of a plexus of middle and late Eocene morphotypes. The specimens that he illustrated (his pl. 177, figs. 8, 9; pl. 244, fig. 1) as representing his concept of the “central type” of the species differ from the holotype (Pl.6.1, Figs. 1-3, this volume) in having 4 chambers in the ultimate whorl (as seen on the umbilical side) in contrast to 3½ in D. galavisi and in lacking a distinct asymmetrically triangular lip (the lip in his pl. 244, fig. 1 looks triangular but appears to be broken). Specimens illustrated in this volume from the upper Eocene of Mississippi, the level from which the species is described, show that the holotype is a typical morphology for the species. Dentoglobigerina galavisi is a common component in upper Eocene and lower Oligocene sediments. The triangular lip or umbilical tooth appears to vary in the degree of its development but in typical specimens it occurs as a thin lip that tapers to a low triangular midpoint. [Olsson et al. 2006]

Catalog entries: Globigerina galavisi;

Type images:

Short diagnosis: The species is characterized by its oval-shaped chambers that surround the umbilicus, the bending and flattening of the ultimate chamber into the umbilicus, and the umbilically confined aperture with an irregular, triangular-shaped lip that projects over the umbilical opening.

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: The species is characterized by its oval-shaped chambers that surround the umbilicus, the bending and flattening of the ultimate chamber into the umbilicus, and the umbilically confined aperture with an irregular, triangular-shaped lip that projects over the umbilical opening. [Olsson et al. 2006]

Wall type: cancellate, honeycomb, normal perforate, nonspinose, Globoquadrina-type wall. [Olsson et al. 2006]

Test morphology: Test trochospiral, globular, oval in outline, chambers globular; in spiral view 3½ ovoid chambers in ultimate whorl, increasing rapidly in size, sutures moderately depressed, straight to slightly curved; in umbilical view 3½ ovoid chambers increasing rapidly in size, sutures deeply depressed, straight; umbilicus small, enclosed by surrounding chambers, aperture centered over the umbilicus, bordered by a thin irregular, triangular-shaped lip that is centered below an ill-defined apertural face; in edge view chambers ovoid in shape, projecting over the umbilicus, ultimate chamber shows a distinct bending and flattening into the umbilicus forming an indistinct umbilical face, aperture positioned at the base of the umbilical face, bordered by an irregular, triangular-shaped lip. [Olsson et al. 2006]

Size: Maximum diameter of holotype 0.46 mm, thickness 0.40 mm. [Olsson et al. 2006]

Character matrix

test outline:Ellipticalchamber arrangement:Trochospiraledge view:Equally biconvexaperture:Umbilical
umb chamber shape:Globularcoiling axis:Lowperiphery:N/Aaperture border:Thick flange
sp chbr shape:Globularumbilicus:Narrowperiph margin shape:Broadly roundedaccessory apertures:None
umbilical or test sutures:Strongly depressedumb depth:Deepwall texture:Cancellateshell porosity:Finely Perforate: 1-2.5µm
spiral sutures:Strongly depresseddiameter mm:0.46width mm:breadth mm:0.4
final-whorl chambers:3.5-3.5

Biogeography and Palaeobiology


Geographic distribution: Widespread in low to mid latitudes. [Olsson et al. 2006]
Aze et al. 2011 summary: Low to middle latitudes; based on Olsson et al. (2006b)

Isotope paleobiology: Recorded (on the basis of oxygen and carbon isotopic data) as a relatively deep dwelling form by Pearson and others (2001) from middle and upper Eocene samples, a habitat corroborated by the boron isotope data of Pearson and Palmer (1999). However Oligocene Samples studied by Van Eijden and Ganssen (1995) registered the most negative ∂18O of planktonic assemblages from ODP Site 758A, indicating a shallow habitat. Douglas and Savin (1978) also recorded relatively negative ∂18O in upper Oligocene Samples. [Olsson et al. 2006]
Aze et al. 2011 ecogroup 3 - Open ocean thermocline. Based on light δ13C and relatively heavy δ18O. Sources cited by Aze et al. 2011 (appendix S3): Wade & Pearson (2008)

Phylogenetic relations: Possibly evolved from an acarininid ancestor in Zone E13 and
gave rise to Dentoglobigerina tripartita (Koch) and probably to Dentoglobigerina pseudovenezuelana (Blow and Banner). [Olsson et al. 2006]

Biostratigraphic distribution

Geological Range:
Notes: Zone E13 to upper Oligocene Zone O6. [Olsson et al. 2006]
Last occurrence (top): within O6 zone (25.21-26.93Ma, top in Chattian stage). Data source: Eocene Atlas
First occurrence (base): within E13 zone (37.99-39.97Ma, base in Bartonian stage). Data source: Eocene Atlas

Plot of occurrence data:

Primary source for this page: Olsson et al. 2006 - Atlas of Eocene Planktonic Foraminifera, chapter 13, p. 403

References:

Bermudez, P.J., (1961). Contribucion al estudio de las Globigerinidea de la region Caribe-Antillana (Paleoceno-Reciente). Mem. III Congreso Geol. Venez. Editorial Sucre, Caracas, 1119-1393 pp.

Blow, W.H. & Banner, F.T., (1962). The mid-Tertiary (Upper Eocene to Aquitanian) Globigerinaceae. In: Eames, F.E. et al. (Editors), Fundamentals of mid-Tertiary Stratigraphical Correlation. Cambridge University Press, Cambridge, pp. 61-151.

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.

Blow, W.H., (1979). The Cainozoic Globigerinida: A study of the morphology, taxonomy, evolutionary relationships and stratigraphical distribution of some Globigerinida (mainly Globigerinacea). E. J. Brill, Leiden, 1413 pp.

Douglas, R.G. & Savin, S.M., (1978). Oxygen isotopic evidence for the depth stratification of Tertiary and Cretaceous foraminifera. Palaeogeography, Palaeoclimatology, Palaeoecology, 3: 175-196.

Eijden & Ganssen 1995 [sorry, not in our bibliography yet]

Fleisher 1975 [sorry, not in our bibliography yet]

Nishi, H. & Chaproniere, G.C.H., (1994). Eocene-Oligocene subtropical planktonic foraminifers at Site 841,. Proceedings of the Ocean Drilling Program, Scientifc Results, 135: 245-266.

Olsson, R.K.; Hemleben, C. & Pearson, P.N., (2006). Taxonomy, biostratigraphy, and phylogeny of Eocene Dentoglobigerina. In: Pearson, P.N. et al. (Editors), Atlas of Eocene Planktonic Foraminifera, Cushman Foundation Special Publication 41. Cushman Foundation Special Publication. Allen Press, Lawrence, Kansas, pp. 401-412.

Pearson, P.N. & Palmer, M.R., (1999). Middle Eocene seawater pH and atmospheric carbon dioxide concentrations. Science, 284: 1824-1826.

Poag, C.W. & Commeau, J.A., (1995). Paleocene to middle Miocene planktic foraminifera of the southwestern Salisbury Embayment, Virginia and Maryland: Biostratigraphy, allostratigraphy, and sequence stratigraphy. Journal of Foraminiferal Research, 25: 134-155.

Poore, R.Z. & Bybell, L.M., (1988). Eocene to Miocene biostratigraphy of New Jersey Core ACGS #4: Implications for regional stratigraphy. U.S. Geological Survey Bulletin 1829: 1-41.

Premoli Silva 1991 [sorry, not in our bibliography yet]

Weinzierl, L.L. & Applin, E.R., (1929). The Claiborne Formation on the Coastal Domes. Journal of Paleontology, 3(4): 384-410.


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Dentoglobigerina galavisi compiled by the pforams@mikrotax project team viewed: 22-10-2017

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