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Rugoglobigerina macrocephala


Classification: pf_mesozoic -> Rugoglobigerinidae -> Rugoglobigerina -> Rugoglobigerina macrocephala
Sister taxa: R. hexacamerata, R. macrocephala, R. milamensis, R. pennyi, R. rugosa, R. spinosa, R. sp.

Taxonomy

Citation: Rugoglobigerina macrocephala Brönnimann, 1952
Rank: Species
Basionym: Rugoglobigerina macrocephala macrocephala
Synonyms: Globotruncana (Rugoglobigerina) macrocephala submacrocephala; Rugoglobigerina macrocephala ornata
Taxonomic discussion: 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. [copied from Chronos database]

Type images:

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.

Entries in the Catalog of original descriptions: Rugoglobigerina macrocephala macrocephala, Globotruncana (Rugoglobigerina) macrocephala submacrocephala, Rugoglobigerina macrocephala ornata

Geological Range:
Last occurrence (top): within A. mayaroensis zone (67.30-69.18Ma, top in Maastrichtian stage). Data source: [copied from Chronos database]
First occurrence (base): within G. gansseri zone (71.75-72.97Ma, base in Campanian stage). Data source: [copied from Chronos database]

Plot of range and occurrence data:

Character matrix

test outline:Lobatechamber arrangement:Trochospiraledge view:-aperture:Umbilical
sp chamber shape:Inflatedcoiling axis:Lowperiphery:N/Aaperture border:Tegilla
umb chbr shape:Inflatedumbilicus:Wideperiph margin shape:Broadly roundedaccessory apertures:Infralaminal
spiral sutures:Moderately depressedumb depth:Shallowwall texture:Meridional costellaeshell porosity:-
umbilical or test sutures:Strongly depressedfinal-whorl chambers:3.0-3.5 N.B. These characters are used for advanced search. N/A - not applicable

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

Pessagno, E. A. (1967). Upper Cretaceous planktonic foraminifera from the western Gulf Coastal Plain. Palaeontographica Americana. 5: 245-445. gs V O

Smith, C. C. & Pessagno, E. A. (1973). Planktonic foraminifera and stratigraphy of the Corsicana formation (Maestrichtian) North-central Texas. Cushman Foundation for Foraminiferal Research, Special Publication. 12: 1-67. gs


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Rugoglobigerina macrocephala compiled by the pforams@mikrotax project team viewed: 21-10-2020

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Short stable page link: http://mikrotax.org/pforams/index.php?id=110501 Go to Archive.is to create a permanent copy of this page - citation notes



Comments (1)

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Le Coze

Citation: Rugoglobigerina macrocephala (Bronnimann, 1952) [no brackets]

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Jeremy Young (UK)

now corrected

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