Catalog - Globigerina brazieri

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Globigerina brazieri

Citation: Globigerina brazieri Jenkins 1966

Type specimens: TF 1497; holotype and 6 paratypes.

Type age (chronostrat): Waitakian Stage (Lower Miocene)

Type locality: New Zealand Geological Survey, Lower Hutt

Type repository: Lower Hutt, New Zealand; New Zealand Geological Survey

Test free, low trochospiral, sinistrally coiled,spiral side convex; equatorial periphery quadrilobate, axial periphery
rounded. Wall calareous, perforate, fairly coarsely pitted. Chambers with spherical outline, 16 arranged in 3 whorls,
with 5 in the first and second whorls and 4 in the third whorl, proloculus diameter about 0.01 mm;
chambers increase rapidly in size in the final whorl. Sutures on the spiral and umbilical sides radial to slightly curved,
depressed. Umbilicus open,deep. Aperture high rounded circular shaped, distinct arch with a thick
rim, umbilical in position..

REMARKS: A study of a growth series of Globigerina brazieri n. sp. in the type sample shows that a specimen having
a 0.18 mm maximum length (No. 46) has a slightly extraumbilical aperture which becomes umbilical in position with
the addition of the succeeding chambers (Nos. 46---51). At all stages of growth the aperture is very high-arched.
There is a reduction in the number of chambers per whorl with the increase in test size, from 5 in the first whorl to
the adult test with 3-31/2 chambers in the final whorl. Rare specimens have a reduced bulla-like final chamber similar
to the illustrated paratype (No. 51). Test coiling in the type sample is 32 sinistral and 21 dextral specimens.
Similar coiling has been recorded in sample SI27/663, from Trig. Z, Otiake, in which there are 25 sinistral and 15
dextral specimens.
G. brazieri is distinguished from Globigerina woodi woodi Jenkins in possessing a higher-arched, more rounded and
nearly circular-shaped aperture with a smoother rim. There is also a more rapid increase in the size of the chambers,
especially in the final whorl of G. brazieri. In the Waitakian rocks of the Bluecliffs section, there is some indication
that G. brazieri is related to and probably evolved from Globigerina woodi woodi Jenkins.
Globigerina brazieri is named after Mr R. C. Brazier, palaeontological artist of the New Zealand Geological Survey,
who has produced the fine drawings of Foraminifera in this paper.

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

Spezzaferri, S., Olsson, R. K., Hemleben, C., Wade, B. S. & Coxall, H. K. (2018d). Taxonomy, biostratigraphy, and phylogeny of Oligocene and Lower Miocene Globoturborotalita. 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 8): 231-268. gs

CATALOG OF ORIGINAL DESCRIPTIONS: Globigerina brazieri Jenkins 1966

Globigerina brazieri

References:

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