CATALOG OF ORIGINAL DESCRIPTIONS: Porticulasphaera Bolli, Loeblich and Tappan 1957
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.
Citation: Porticulasphaera Bolli, Loeblich and Tappan 1957Rank: GenusType species: Globigerina mexicana Cushman, 1925Type age (chronostrat): Middle Eocene.
Current identification:
Original Description Test free, subglobular, early portion trochospiral, final chamber much inflated to almost spherical, and strongly enveloping, covering the umbilical region of the early coil; sutures depressed, radial to curved; wall calcareous, comparatively thick, coarsely perforate, radial in structure, surface with numerous fine elongate spines, broken from the exterior, but those of the early portion may be preserved in the interior and visible in dissected specimens; primary aperture in the early portion interiomarginal, umbillical, with secondary sutural openings on the spiral side, as in Globigerinoides, the umbilical aperture covered by the final enveloping chamber of the adult, which has smaller sutural secondary apertures around its lower margin; these, together with the secondary sutural apertures on the spiral side, remain uncovered. Size: Etymology: Porticula, L., diminutive of porticus, an arcade, series of arches + sphaera, L., ball; gender, feminine. Extra details from original publication Remarks: Porticulasphaera, new genus, resembles Orbulina d'Orbigny in having a strongly embracing final chamber, although less inflated. In Porticulasphaera the early coil always remains visible, and there are no areal secondary apertures as in Orbulina.
It resembles Globigerinoides Cushman in having the multiple sutural secondary apertures in addition to the large interiomarginal umbilical primary aperture in the early portion, but differs in having the embracing final chamber obscuring the primary umbilical aperture, the adult possessing only the small sutural secondary openings.
Porticulasphaera, new genus, differs from Globigerapsis, new genus, in having the Globigerinoides-type of secondary apertures on the spiral side in the early coil. Editors' Notes
References:
Bolli, H. M., Loeblich, A. R. & Tappan, H. (1957). Planktonic foraminiferal families Hantkeninidae, Orbulinidae, Globorotaliidae and Globotruncanidae. In, Loeblich, A. R. , Jr., Tappan, H., Beckmann, J. P., Bolli, H. M., Montanaro Gallitelli, E. & Troelsen, J. C. (eds) Studies in Foraminifera. U.S. National Museum Bulletin . 215: 3-50. gsVO
Porticulasphaera compiled by the pforams@mikrotax project teamviewed: 6-2-2023
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