Catalog - Rugoglobigerina macrocephala macrocephala <title>Catalog - Rugoglobigerina macrocephala macrocephala

CATALOG OF ORIGINAL DESCRIPTIONS: Rugoglobigerina macrocephala macrocephala Bronnimann 1952

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 -> R -> Rugoglobigerina -> Rugoglobigerina macrocephala macrocephala
Other pages this level: R. alpina, R. jerseyensis, R. kingi, R. lobatula, R. macrocephala macrocephala, R. macrocephala ornata, R. mexicana, R. milamensis, R. praehelvetica, R. pseudorugosa, R. reicheli hexacamerata, R. reicheli pustulata, R. reicheli reicheli, R. rugosa pennyi, R. rugosa rotundata, R. spinosa, R. tradinghousensis

Rugoglobigerina macrocephala macrocephala

Citation: Rugoglobigerina macrocephala macrocephala Bronnimann 1952
Rank: sub-species
Type specimens: 371324 T.L.L.Cat.Nos.155591-155594-Plate 2,figs.1-3.
Type sample (& lithostrat): upper Guayaguayare Fm.
Type age (chronostrat): Maastrichtian
Type locality: Trinidad Leaseholds Ltd. Catalogue nos. 155591-155594, subsurface samples from the Guayaguayare area, southeastern, Trinidad, B.W.I.
Type repository: Washington; USNM

Linked specimens: USNM-371324

Current identification/main database link: Rugoglobigerina macrocephala Brönnimann, 1952


Original Description

The small to medium-sized trochoidal test is 4 to 5-chambered in the adult. The rather small and deep umbilicus is filled with matrix and no signs of a covering plate were observed. The spiral side is centrally depressed and shows in well-preserved specimens about 2 whorls. The subglobular chambers are truncate toward the umbilicus and increase rapidly in size as added. The peripherally somewhat flattened end chamber is much larger than the penultimate one, and in many individuals equals the whole preceding spiral in size. The straight sutures are well developed in the adult stage. The large semicircular aperture of the end chamber is provided with a minute liplike border and opens into the umbilicus. The apertures of the preceding chambers are not visible. The walls are thick and the surface is rugose. The ornamentation of the early chambers is irregular and coarsely hispid whereas the 2 last-formed chambers show the meridional pattern. The rugosities are delicate and composed of numerous fine continuous and discontinuous ridges. All the investigated individuals are dextrally coiling.

Size:
The maximum diameter of paratypes ranges from 0.275mm. to 0.35mm. Holotype:Maximum diameter 0.325mm.Diameter of aperture O.Imm.End chambers: radial diameter O.175mm.;tangential diameter 0.25mm.;thickness 0.225mm

Etymology:

Extra details from original publication
Remarks: This subspecies is the central form of the macrocephala group, typified by the large-sized end chamber. It is distinguished from the subspecies ornata by the relatively small test and by the coarsely and irregularly ornamented early chambers of the last volution. Only the 2 last chambers carry the meridional pattern.

Editors' Notes

References:

Brönnimann, P. (1952c). Globigerinidae from the Upper Cretaceous (Cenomanian-Maestrichtian) of Trinidad, B. W. I. Bulletins of American Paleontology. 34(140): 1-70. gs


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Rugoglobigerina macrocephala macrocephala compiled by the pforams@mikrotax project team viewed: 5-2-2023

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