Catalog - Globorotalia bullbrooki Catalog - Globorotalia bullbrooki

CATALOG OF ORIGINAL DESCRIPTIONS: Globorotalia bullbrooki Bolli 1957

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 -> Globorotalia -> Globorotalia bullbrooki
Other pages this level: << < G. archeomenardii, G. armenica, G. australiformis, G. avanensis, G. barisanensis, G. bella, G. berggreni, G. bermudezi, G. berwaliana, G. birnageae, G. bollii, G. bonairensis, G. bononiensis, G. bouregregensis, G. broedermanni lodoensis, G. bullbrooki, G. bykovae, G. bykovae minoritesta, G. californica, G. californica Smith, G. canariensis minima, G. capdevilensis, G. cavernula, G. caylaensis, G. centralis, G. cerroazulensis cunialensis, G. cerroazulensis pomeroli, G. cerroazulensis possagnoensis, G. challengeri, G. chapmani, G. cibaoensis> >>

Globorotalia bullbrooki

Citation: Globorotalia bullbrooki Bolli 1957
taxonomic rank: Species
Type specimens: Holotype (USNM P5742); Figured paratype (USNM P5743)
Type age (chronostrat): Hantkenina aragonensis zone to Globigerapsis kugleri zone
Type locality: Locality: Holotype USNM P5742) and figured paratype (USNM P5743) from the Hantkenina aragonensis zone, Navet formation; holotype from outcrop on left side of right branch of Nariva River, about 450 feet from its junction. Central Range, Trinidad (coordinates N:314350 links; E:487360 links); paratype from upper part of small ravine between mileposts 12 1/4 and 12 1/2 of the Brasso-Tamana Road and Navet River (see text-fig. 25); samples K 9077, 8817 (TTOC 178166, 177758).
Type repository: Washington; USNM

Linked specimens: USNM-5743 USNM-5742

Current identification/main database link: Acarinina bullbrooki (Bolli 1957)


Original Description

Shape of test of spiral side almost flat or low trochospiral, umbilical side strongly convex, subangular. Wall calcareous, perforate, surface covered with short, blunt spines. Chambers subangular, inflated; about tweleve to fifteen, arranged in about 2.5 whorls; the four chambers of the last whorl increase fairly rapidly in size. Sutures on spiral side oblique or raidal, depressed; on umbilical side radial, depressed. Umbilicus narrow, deep. Aperture a low arch, interiomarginal, umbilical-extraumbilical. Coiling without distinct pattern in the preliminary study of eight isolated samples belonging to Hantkenina aragonensis zone. In four of these samples, seventy to ninety percent of the specimens coiled dextrally; in two a preference for sinistral coiling was observed and in two the specimens coiled at random. It may be of interest to note that in the samples with a predominance of dextrally coiled specimens, Clavigerinella was found but Hantkenina was absent. To gain a clear picture of the coiling pattern in Globorotalia bullbrooki it will be necessary to make further investigations in a more nearly complete stratigraphic section.

Size:
Largest diameter of holotype 0.5 mm.

Etymology:
The species is named for Mr. J. A. BuUbrook, geologist and archeologist, Trinidad.

Extra details from original publication
Stratigraphic range: Hantkenina aragonensis zone to Globigerapsis kugleri zone, Navet formation.

Remarks: Globorotalia bullbrooki, new species, is distinguished from G.aspensis (Colom) by its more subangular test and by the presence of 4 chambers in the last whorl instead of the 5-7 of that species.

Globorotalia crassata (Cushman), often referred to in publications, may be close to the new species. The single spiral view of the holotype given by Cushman (1925) is not sufficient for an accurate determination and comparison. G. crassata as figured by Cushman and Bermudez (1949) shows 5 1/2 chambers in the last whorl as against the 4 commonly found in G. bullbrooki. G. crassata var. densa (Cushman) is described as differing from G. crassata in its more rounded compact form, rounded periphery, and in having only 4
chambers in the last formed coil instead of 5 or 6 as in the typical form. No figure was given by Cushman for this variety. On the basis of the scanty description alone it is not possible to compare it with Globorotalia bullbrooki or any other possibly synonymous Navet
species.

Specimens found among the middle Eocene foraminiferal fauna of a Mid-Pacific core (see p. 169), are indistinguishable from Globorotalia bullbrooki, with the exception that they possess small sutural supplementary apertures on the spiral side, which are typical of
the genus Truncorotaloides. It is likely that G. bullbrooki also possesses such accessory apertures which, however, cannot be seen due to the poor preservation, and should therefore be placed in the genus Truncorotaloides.

References:

Berggren, W. A., Pearson, P. N., Huber, B. T. & Wade, B. S. (2006b). Taxonomy, biostratigraphy, and phylogeny of Eocene Acarinina. 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 9): 257-326. gs O

Bolli, H. M. (1957a). Planktonic foraminifera from the Eocene Navet and San Fernando formations of Trinidad. In, Loeblich, A. R. , Jr., Tappan, H., Beckmann, J. P., Bolli, H. M., Montanaro Gallitelli, E. & Troelsen, J. C. (eds) Studies in Foraminifera. U.S. National Museum Bulletin . 215: 155-172. gs

Bolli, H. M., Loeblich, A. R. & Tappan, H. (1957). Planktonic foraminiferal families Hantkeninidae, Orbulinidae, Globorotaliidae and Globotruncanidae. In, Loeblich, A. R. , Jr., Tappan, H., Beckmann, J. P., Bolli, H. M., Montanaro Gallitelli, E. & Troelsen, J. C. (eds) Studies in Foraminifera. U.S. National Museum Bulletin . 215: 3-50. gs

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Globorotalia bullbrooki compiled by the pforams@mikrotax project team viewed: 9-9-2024

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