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Contusotruncana fornicata


Classification: pf_mesozoic -> Globotruncanidae -> Contusotruncana -> Contusotruncana fornicata
Sister taxa: C. contusa, C. fornicata, C. morozovae, C. patelliformis, C. plicata, C. plummerae, C. walfischensis, C. sp.,

Taxonomy

Citation: Contusotruncana fornicata (Plummer, 1931)
Rank: Species
Basionym: Globotruncana fornicata
Synonyms: Globotruncana fornicata motai; Globotruncana contusa scutilla; Globotruncana sudrensis; Globotruncana thalmanni thalmanni;
Taxonomic discussion: This species at its type locality in the Taylor formation (Station 226- T-8) is easily distinguished from its congeners by its narrow and strongly arched chambers that sweep in strong curves on the dorsal face. The chambers of the microspheric form are even more strongly curved than those of the megalospheric. Its dorsal sutures and margin are finely delineated by narrow and delicately beaded elevations which show a tendency to merge into sharp depressions from the periphery inward toward the earlier whorl. The center of each test is occupied by a globigerine spire of globular chambers, and this inflation persists in ma y tests in the strongly inflated inner extremities of the more mature chambers on the dorsal side. The dorsal convexity of the test varies from moderate to very high, especially in the microspheric form. The double carination is very characteristic of this species, but the secondary keel in some specimens weakens in late maturity. [copied from Chronos database]

Type images:

Original description: "Test biconvex, periphery truncate and lobate; chambers seven in final convolution, long narrow, strongly curved, smooth; dorsal sutures finely beaded, very strongly oblique and lightly curved; ventral sutures elevated and curved strongly forward in maturity, depressed and more nearly radial in youth; umbilicus broad and open; apertures from last 3 or 4 chambers of the final whorl into the umbilicus. Average diameter .4 mm; commonly up to .5 mm."

Entries in the Catalog of original descriptions: Globotruncana fornicata, Globotruncana fornicata motai, Globotruncana contusa scutilla, Globotruncana sudrensis, Globotruncana thalmanni thalmanni, Globotruncana arca caribica

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 D. concavata zone (86.71-89.91Ma, base in Turonian stage). Data source: [copied from Chronos database]

Plot of occurrence data:

Dec 2017 - Plotting of Neptune data has been re-enabled on the Mesozoic pages following revision of the age-models in Neptune. The data is, however, still very sparse for the Early Cretaceous

Character matrix

test outline:Subcircularchamber arrangement:Trochospiraledge view:Equally biconvexaperture:Umbilical
sp chamber shape:Crescenticcoiling axis:Lowperiphery:Double keelaperture border:Tegilla
umb chbr shape:-umbilicus:Wideperiph margin shape:Subangularaccessory apertures:Intralaminal
spiral sutures:Raised beadedumb depth:Shallowwall texture:-shell porosity:-
umbilical or test sutures:Raised beadedfinal-whorl chambers:4.5-5.0 N.B. These characters are used for advanced search. N/A - not applicable

References:

Almogi-Labin, A., Reiss, Z & Caron, M. (1986). Senonian globotruncanidae from Israel. Eclogae Geologicae Helvetiae. 79(3): 849-895. gs V O

Huber, B. T., Petrizzo, M. R., Watkins, D. K., Haynes, S. J. & MacLeod, K. G. (2017a). Correlation of Turonian continental margin and deep-sea sequences in the subtropical Indian Ocean sediments by integrated planktonic foraminiferal and calcareous nannofossil biostratigraphy. Newsletters on Stratigraphy. 50: 141-185. gs

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

Plummer, H. J. (1931b). Some Cretaceous foraminifera in Texas. University of Texas Bulletin. 3101: 109-203. gs

Postuma, J. A. (1971). Manual of planktonic foraminifera. Elsevier for Shell Group, The Hague. 1-406. gs


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Contusotruncana fornicata compiled by the pforams@mikrotax project team viewed: 1-10-2020

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Short stable page link: http://mikrotax.org/pforams/index.php?id=110069 Go to Archive.is to create a permanent copy of this page - citation notes



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