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.
Linked specimens: USNM-5078
Current identification/main database link: Globotruncana arca (Cushman, 1926)
Test biconvex, the periphery truncate, about 7 chambers in the last-formed coil; chambers very distinct; sutures both on the dorsal and ventral sides limbate, on the dorsal side curved, raised above the general surface in a distinctly beaded ornamentation, fusing with the raised periphery, the early sutures often more beaded than later ones, on the ventral side the chambers of the last-formed coil do not extend in to the center, leaving a distinct umbilical area; aperture elongate on the ventral side at the base of the last-formed chamber.
Size: Diameter usually less than 1 mm.
Extra details from original publication
This is the most abundant of all the species of the so-called Papagallos series in the Upper Cretaceous of the Tampico region. It has a very broad distribution both geographically and vertically, in the Upper Cretaceous series. Through its wide vertical distribution, it shows several varietal forms, some of which may be more easily distinguished than others. In one of these the entire test becomes much flattened and the truncate character of the periphery is much more marked than in the typical form. In another the periphery is developed into distinct angles. Of the various varieties Pulvinulina arca Cushman, n. sp., var contusa. Cushman, n. var. is perhaps the most distinctive.
Pulvinulina arca compiled by the pforams@mikrotax project team viewed: 5-8-2021
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