Original description: Pulvinulina arca contusa Cushman 1926: "Test large, robust, spiroconvex with a sharply angular, polygonal outline and a peculiarly shaped, folded surface; dorsal side highly trochopsirally coiled, with bluntly curved convex folds radiating from the apex and shallowly concave, broader depressions running between the radiating folds, and widening away towards the base; ventral side concave; equatorial periphery roughly pentagonal with blunt corners, gently undulating and very weakly, if at all, lobate; periphery with two well-developed, heavily beaded keels, enclosing a relatively wide, almost horizontal, slightly depressed peripheral band; axial periphery subangular, distinctly truncate; chambers, on the dorsal side 23, arranged in 4 dextrally coiled whorls; they increase moderately and regularly in size till shortly before the beginning of the last whorl where they start to enlarge very rapidly and to change in shape; the initial chambers are small, inflated globigerine; they increasemoderately in size and are followed by relatively large, globular, inflated cahambers which increase more rapidly in size, and towards the end of the penultimate whorl; the last whorl is composed of 4, very long, very narrow, broadly curved, roughly oblong, undulating chambers which are extremely elongated in the direction of coiling; on the ventral side the chambers are 4, very large, angular, roughly oblong, very narrow, strongly elongated in the direction of coiling with their surfaces gently sloping towards the umbilicus; sutures on the dorsal side slightly curved, faintly raised and delicately beaded in the early part, strongly curved, raised, thichened and heavily beaded later; on the ventral side the sutures are straight, radial and depressed; umbilicus rhomboidal in outline, relatively wide, deep, surrouncded by beaded umbilical ridges and covered by complex tegilla of which remnants are still preserved; primary apertures interiomarginal, umbilical; tegilla, with accessory apertures, only poorly preserved; wall calcareous, perforate except for the imperforate keels, peripheral band and tegilla; surface delicately papillose especially on the early part and on the ventral side."
Entries in the Catalog of original descriptions:
Globotruncana contusa galeoidis;
Globotruncana linnei caliciformis;
Pulvinulina arca contusa;
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 R. fructicosa zone (69.18-70.14Ma, base in Maastrichtian stage). Data source: [copied from Chronos database]
Plot of occurrence data:
NB Plotting of Neptune data has been disabled on the Mesozoic pages because the dataset is both small and badly affected by a few sites with erroneous age models (our obs Huber, Petrizzo, Young, Nov 2016). The data can still be viewed via the range plottertool - tools menu.
|test outline:||Subpolygonal||chamber arrangement:||Trochospiral||edge view:||Spiroconvex||aperture:||Umbilical|
|umb chamber shape:||Crescentic||coiling axis:||High||periphery:||Double keel||aperture border:||Thick porticus|
|sp chbr shape:||Crescentic||umbilicus:||Wide||periph margin shape:||Subangular||accessory apertures:||Intralaminal|
|umbilical or test sutures:||Moderately depressed||umb depth:||Deep||wall texture:||Finely pustulose||shell porosity:||Finely Perforate: 1-2.5µm|
|spiral sutures:||Raised beaded||diameter mm:||0.50 mm - 0.70 mm||width mm:||0.45 mm||breadth mm:|
Cushman, J.A., (1926). Recent foraminifera from Porto Rico. Papers from the Department of Marine Biology of the Carnegie Institution of Washington, 23: 73-84. Cushman, J.A., (1926). The foraminifera of the Velasco shale of the Tampico embayment. Bulletin of the American Association of Petroleum Geologists, 10(6): 581-612. Cushman, J.A., (1926). Foraminifera of the genera Siphogenerina and Pavonina. Proceedings of the United States National Museum, 67(2597): 1-24.
Cushman, J.A., (1926). Recent foraminifera from Porto Rico. Papers from the Department of Marine Biology of the Carnegie Institution of Washington, 23: 73-84.
Cushman, J.A., (1926). The foraminifera of the Velasco shale of the Tampico embayment. Bulletin of the American Association of Petroleum Geologists, 10(6): 581-612.
Cushman, J.A., (1926). Foraminifera of the genera Siphogenerina and Pavonina. Proceedings of the United States National Museum, 67(2597): 1-24.
Contusotruncana contusa compiled by the pforams@mikrotax project team viewed: 19-10-2017
Go to Archive.is to create a permanent copy of this page - citation notes