Taxonomy
Original description: Spiral side flattened to gently convex; periphery lobulate chambers increasing rapidly in size; nepionic chambers spherical; later chambers becoming markedly ovate and highly compressed; early chambers coarsely spirose; last 2-3 chambers smooth, often a modified hemispherical shape with a sharp dorsal keel which appears to be radial, hyaline, perforate; sutures depressed, radial, slightly curved on both spiral and umbilical sides; aperture interiomarginal; appears to be a low arch, extraumbilical in position; large umbilical flaps extend into a broad umbilicus from each chamber.
Entries in the Catalog of original descriptions: Praeglobotruncana hessi compressiformis
Character matrix
test outline: | Circular | chamber arrangement: | Trochospiral | edge view: | Equally biconvex | aperture: | Umbilical-extraumbilical |
sp chamber shape: | Elongate | coiling axis: | Very low | periphery: | N/A | aperture border: | Thin flange |
umb chbr shape: | Globular | umbilicus: | Wide | periph margin shape: | Subangular | accessory apertures: | Umbilical |
spiral sutures: | Moderately depressed | umb depth: | Shallow | wall texture: | Smooth | shell porosity: | Finely Perforate: 1-2.5µm |
umbilical or test sutures: | Moderately depressed | final-whorl chambers: | 4.5-5.5 | N.B. These characters are used for advanced search. N/A - not applicable |
Geological Range:
Last occurrence (top): within Maastrichtian Stage (66.04-72.17Ma, top in Maastrichtian stage). Data source: [copied from Chronos database]
First occurrence (base): within Maastrichtian Stage (66.04-72.17Ma, base in Maastrichtian stage). Data source: [copied from Chronos database]
Plot of range and occurrence data:
Pessagno, E. A. (1962). The Upper Cretaceous stratigraphy and micropaleontology of south-central Puerto Rico. Micropaleontology. 8(3): 349-368. gsReferences:
Globotruncanella compressiformis compiled by the pforams@mikrotax project team viewed: 14-12-2024
Short stable page link: https://mikrotax.org/pforams/index.php?id=110180 Go to Archive.is to create a permanent copy of this page - citation notes |
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