Catalog - Globoquadrina pseudofoliata

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Globoquadrina pseudofoliata

Citation: Globoquadrina pseudofoliata Parker 1967

Type age (chronostrat): Pliocene or lower? Pleistocene

Type locality: LSDH 78 P, 30-32 cm. Lat 4°31'S., long. 168°02'E., 3208 m; Pacific Ocean.

Type repository: Washington - USNM

Test large, lobulate, with a rounded periphery, often biconvex; chambers globular, inflated, increasing rapidly in size as added, about 20 in the adult, 4 in the final whorl, the final chamber sometimes reduced in size; sutures depressed; wall of adults finely pitted, much coarser in juvenile stages; aperture umbilical, with triangular umbilical teeth.

Largest diameter up to 0.9 mm., greatest thickness up to 0.6 mm.

Remarks. Specimens of this species are similar in shape to Globigerina foliata Bolli (compared both to the holotype and to specimens sent to M. N. Bramlette by H. M. Bolli), but that species is a true globigerinid with a hispid wall; in addition, G. foliata has chambers which increase more rapidly in size as added, lacks the globoquadrine umbilical teeth, and is much smaUer in size. Globoquadrina pseudofoliata is more compressed, the chambers more globular and increasing more rapidly in size as added than in either G. conglomerata or G. venezuelana, to which species it seems most closely affiliated. The adults are distinctive and easily distinguished from adults of either of these species. G. pseudofoliata shows little variation except for the frequent reduction in size of the final chamber.
This species apparently branched off from G. venezuelana at the base of Zone N.19. In CAP 38 BP it seems to alternate in a few samples with that species, but this is not the case in LSDH 78 P, in which it occurs with G. venezuelana commonly in several samples. It is impossible, however, to differentiate the early stage juveniles of G. pseudofoliata from those of G. venezuelana. The flattened spiral side and sharp periphery differentiate later juveniles of this new species from those of G. hexagona, which they somewhat resemble. The figured early stage (Pl. 27, fig. 2) was dissected from an adult to make certain of its identity. This specimen has heavy secondary spines which have not been seen in adults or in undissected early stages.
This species appeared in the core section near the base of Zone N.19 and probably became extinct in the lower part of the Quaternary, although this is not sure because of the uncertainty about what part of the Quaternary is represented near the tops of cores. The evidence from CAP 38 BP, however, suggests this possibility.

References:

Parker, F. L. (1967). Late Tertiary biostratigraphy (planktonic foraminifera) of tropical Indo-Pacific deep-sea cores. Bulletins of American Paleontology. 52(235): 115203-. gs

CATALOG OF ORIGINAL DESCRIPTIONS: Globoquadrina pseudofoliata Parker 1967

Globoquadrina pseudofoliata

References:

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