CATALOG OF ORIGINAL DESCRIPTIONS: Globigerina pauciloculata Jenkins 1966

This page provides data from the catalog of type descriptions. The catalog is sorted alphabetically. Use the current identification link to go back to the main database.


Higher levels: pf_cat -> G -> Globigerina -> Globigerina pauciloculata
Other pages this level: << < G. ouachitaensis, G. ouachitaensis gnaucki, G. ouachitaensis senilis, G. ovoidea, G. oxfordiana, G. panormensis, G. parabulloides, G. paradubia, G. paraobesa, G. paratriloculinoides, G. paravenezuelana, G. parisiensis, G. partidiana, G. parva, G. patagonica, G. pauciloculata, G. pera, G. picassiana, G. pileata, G. planispira, G. planoexilis, G. polusi, G. portsdownensis, G. postcretacea, G. posttriloculinoides, G. posttriloculinoides clinata, G. praebulloides, G. praebulloides leroyi, G. praebulloides occlusa, G. praebulloides pseudociperoensis, G. praebulloides pseudoleroyi> >>

Globigerina pauciloculata

Citation: Globigerina pauciloculata Jenkins 1966
Rank: Species
Type locality: S68/197, F 5667, grid ref. 974137, Middle Waipara River, 103 chains WSW of gorge, N bank, about 5-10 ft above the base of the Waipara Greensand.
Type age (chronostrat): Lower part of Teurian Stage (Danian).
Type specimens: TF 1500: holotype and 15 paratypes.
Type repository: Lower Hutt, New Zealand; New Zealand Geological Survey

Current identification/main database link:


Original Description
Test free, small, low trochospiral, dextrally coiled; equatorial periphery slightly lobate;
sutures on the umbilical and spiral side radial to slightly curved; umbilicus and umbilical sutures covered by a
thin layer of minutely granular test material. Wall calcareous, thin, perforate with small hexagonal pores; smooth,
except in the umbilical area and umbilical sutures. Chambers circular in outline and increasing slowly in
size, 8 forming the test, 5 in the first whorl, and nearly 5 in the final
whorl; proloculus large, diameter 0.04 mm.

Size: Maximum diameter 0.17 mm.

Extra details from original publication
REMARKS: Three varieties of test morphology have been distinguished within the type population of Globigerina pauciloculata n. sp., but they are extreme variants and within examined populations all the intermediate forms are present.
Variety (a): (Nos. 16-25). Includes the holotype. Distinguished by its comparatively low-spired trochoid test with 41/2-5 chambers in the final whorl slowly increasing in size. The aperture in juveniles is small, interiomarginal, extra-umbilical in position tending to become more umbilical with the addition of chambers. The largest test of this variety is 0.19 mm long and the maximum chamber number found in a test is 9.
Variety (b): (Nos. 26-33). The first whorl has only 4 chambers; they increase rapidly in size and with the addition of further chambers form a comparatively low trochoid test. Aperture interiomarginal, extra-umbilical to umbilical in the juveniles, becoming umbilical prior to the addition of the final chamber. A few tests have an umbilical bulla extending along the umbilical sutures. Maximum test diameter observed 0.21 mm and maximum chamber number 8.
Variety (c): (Nos. 34--41). Tests with 4-5 chambers in the primary whorl, with proloculus usually projecting beyond the surface of the first whorl. Final whorl with 4 chambers, the last occasionally modified as an umbilical bulla. The aperture tends to be umbilical throughout growth. Test high-spired, maximum test diameter 0.2 mm, maximum number of chambers 10.
In all 3 varieties the diameter of the proloculus varies between 0.01 and 0.06 mm, with a tendency for specimens having a small proloculus to have 5, chambers in the first whorl and a smaller test. The inside of the first few chambers has small spines.
The final chamber of adult tests varies from smaller to larger than the antepenultimate chamber; it is usually thinner and smoother walled and in many cases is broken. The Position of the last chamber can vary from the normal next position in the final whorl to an umbilical position. No aperture is visible after the addition of the final chamber.
There appears to be an increase in the test-wall pore diameter from small in the oldest samples to much larger in the topmost sample in the Middle Waipara River section, in a manner similar to that described by Hofker(1962) in the type Danian Foraminifera. However, G. pauciloculata does not have any obvious close morphological affinities with other described planktonic Foraminifera from the Danian Stage.
A thin section of G. pauciloculata (Fig. 5, No. 42) shows the test wall to be bilamellar, thus corresponding to the Observations made by Reiss (1963) on the wall structure of Globigerina.
Nevertheless G. pauciloculata at its earliest stage of development in the lowest samples seems to lack the characteristic Globigerina test-wall ornamentation and adult umbilical aperture.It is therefore regarded by the writer as a primitive Globigerina.
The initial appearance of G. pauciloculata, in sample S68/948, is about 50 ft above the top of the beds containing Maestrichtian planktonic Foraninifera in the Middle Waipara section. The rocks in the 50 ft interval contain no planktonic Foraminifera and only a few benthic species.
The specific name pauciloculata is taken from the Latin paucus meaning "few"" and loculus meaning ""cell"" or ""chamber""."

Editors' Notes
The article was published in the December 1965 issue of the journal but appeared in early 1966, so for taxonomy the correct date is 1966

References:

Jenkins, D. G. (1966b). Planktonic foraminiferal zones and new taxa from the Danian to lower Miocene of New Zealand. New Zealand Journal of Geology and Geophysics. 8 [1965](6): 1088-1126. gs


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Globigerina pauciloculata compiled by the pforams@mikrotax project team viewed: 27-11-2020

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