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.
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
Rugoglobigerina macrocephala macrocephala compiled by the pforams@mikrotax project teamviewed: 5-2-2023
Bronnimann 1952 pl2 f1-3.JPG
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Bronnimann 1952 pl2 f1-3.JPG
holotype-236~a.jpg
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