Dentoglobigerina taci


Classification: pf_cenozoic -> Globigerinidae -> Dentoglobigerina -> Dentoglobigerina taci
Sister taxa: D. juxtabinaiensis, D. binaiensis, D. sellii, D. tapuriensis, D. baroemoenensis, D. larmeui, D. galavisi, D. altispira, D. globosa, D. globularis, D. prasaepis, D. pseudovenezuelana, D. taci, D. tripartita, D. eotripartita, D. venezuelana, D. sp.,

Taxonomy

Citation: Dentoglobigerina taci Pearson & Wade 2015
Rank: Species
Synonyms:
Taxonomic discussion:

According to Pearson and Wade (2015), taci is morphologically and evolutionarily intermediate between D. galavisi and D. tapuriensis. [Wade et al. 2018]

Catalog entries: Dentoglobigerina taci

Type images:

Distinguishing features: 3½ globular chambers in final whorl.
Umbilicus open, square; with thin lip.

NB These concise distinguishing features statements are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus.
They are being edited as the site is developed and comments on them are especially welcome.

Description


Diagnostic characters:

Dentoglobigerina taci is similar in gross morphology to D. galavisi but has a more open umbilicus and lacks the irregular triangular lip projecting over the umbilicus that is part of the diagnosis of D. galavisi sensu stricto (Blow, 1979; Olsson and others, 2006). Unlike D. galavisi it generally has a lip of relatively constant thickness rather than a tooth, and a rectangular umbilical depression rather than triangular in D. galavisi. This species differs from D. prasaepis by its less compressed chambers and square (rather than rectangular) umbilicus and from D. pseudovenezuelana principally by having a more open umbilicus than is normally seen in that species and by lacking the densely pustulose umbilical ornamentation characteristic of that species. It differs from D. tapuriensis principally by lacking the broad final chamber and broad, low aperture that is characteristic of that species (modified from Pearson and Wade, 2015). Dentoglobigerina taci is distinguished from Subbotina eocaena by its less globular chambers and more open, higher arched aperture.

Dentoglobigerina taci is morphologically similar to Globoturborotalita cancellata (Pessagno), but differs by having broader chambers, giving the test a squarer and less lobate outline, and the final chamber overhangs the umbilicus, as is typical in the genus. Its also has a less cancellate wall texture (see Chapter 8, this volume, for discussion and SEM images of G. cancellata). [Wade et al. 2018]


Wall type: Cancellate and probably spinose in life. [Wade et al. 2018]

Test morphology: “Test large, globular, approximately 12-13 chambers arranged in a moderate trochospiral, outline oval and slightly lobate, chambers globular and radially compressed; in spiral view 3½ appressed and embracing chambers in final whorl, increasing moderately to rapidly in size, sutures slightly curved, depressed; in umbilical view 3½ globular and appressed chambers, increasing moderately rapidly in size, sutures depressed, straight or slightly curved, umbilicus moderately wide, rectangular, and deep; aperture umbilical, centrally placed usually with a lip of constant thickness; in edge view chambers globular in shape, embracing, the final chamber tending to lean slightly over the umbilicus. May be dextral or sinistral, with a slight bias in favor of sinistral coiling.” (Pearson and Wade, 2015:18.) [Wade et al. 2018]

Size: Maximum diameter of holotype 0.39 mm. [Wade et al. 2018]

Character matrix

test outline:Lobatechamber arrangement:Trochospiraledge view:Concavo-convexaperture:Umbilical
sp chamber shape:Globularcoiling axis:Moderateperiphery:N/Aaperture border:Thin lip
umb chbr shape:Globularumbilicus:Wideperiph margin shape:Broadly roundedaccessory apertures:None
spiral sutures:Moderately depressedumb depth:Deepwall texture:Cancellateshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Strongly depressedfinal-whorl chambers:3.5-3.5 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution: Low latitudes, currently confirmed only from the Indian Ocean (Tanzania), Gulf of Mexico (US Gulf Coast) and equatorial Pacific Ocean (IODP Site U1334). [Wade et al. 2018]

Isotope paleobiology: Multispecies stable isotope data indicate negative δ18O values in comparison to the rest of the assemblage, suggesting calcification in the mixed-layer (Moore and others, 2014, recorded as Dentoglobigerina sp. 1). [Wade et al. 2018]

Phylogenetic relations: Evolved from D. galavisi in the upper Eocene (Pearson and Wade, 2015) and is ancestral to D. tapuriensis. [Wade et al. 2018]

Most likely ancestor: Dentoglobigerina galavisi - at confidence level 4 (out of 5). Data source: Pearson & Wade 2015, p19.
Likely descendants: Dentoglobigerina prasaepis;

Biostratigraphic distribution

Geological Range:
Notes: Uppermost Eocene to lower Oligocene. The highest occurrence has yet to be determined. [Wade et al. 2018]
Last occurrence (top): within O1 zone (32.10-33.90Ma, top in Rupelian stage). Data source: Wade et al. 2018 f11.1
First occurrence (base): within E16 zone (33.90-34.68Ma, base in Priabonian stage). Data source: Wade et al. 2018 f11.1

Plot of occurrence data:

Primary source for this page: Wade et al. 2018 - Olig Atlas chap.11 p.365;

References:

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. 2: 1-1413. gs

Moore, T. C. et al. (2014). Equatorial Pacific Productivity Changes near the Eocene-Oligocene Boundary. Paleoceanography. 29: 825-844. gs

Olsson, R. K., Hemleben, C. & Pearson, P. N. (2006a). Taxonomy, biostratigraphy, and phylogeny of Eocene Dentoglobigerina. In, Pearson, P. N. , Olsson, R. K. , Hemleben, C. , Huber, B. T. & Berggren, W. A. (eds) Atlas of Eocene Planktonic Foraminifera. Cushman Foundation for Foraminiferal Research, Special Publication. 41(Chap 13): 401-412. gs

Pearson, P. N. & Wade, B. S. (2015). Systematic taxonomy of exceptionally well-preserved planktonic foraminifera from the Eocene/Oligocene boundary of Tanzania. Cushman Foundation for Foraminiferal Research, Special Publication. 45: 1-85. gs

Wade, B. S., Pearson, P. N., Olsson, R. K., Fraass, A. J., Leckie, R. M. & Hemleben, C. (2018c). Taxonomy, biostratigraphy, and phylogeny of Oligocene and Lower Miocene Dentoglobigerina and Globoquadrina. In, Wade, B. S. , Olsson, R. K. , Pearson, P. N. , Huber, B. T. & Berggren, W. A. (eds) Atlas of Oligocene Planktonic Foraminifera. Cushman Foundation for Foraminiferal Research, Special Publication. 46(Chap 11): 331-384. gs


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Dentoglobigerina taci compiled by the pforams@mikrotax project team viewed: 17-10-2019

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