Taxonomy
Original description: "Test biconvex, low trochospiral, evolute, umbilicate, consisting of 3-31/2 whorls; equatorial periphery subcircular, moderately lobulate. Chambers globular, 5-7 (usually 6) in final whorl, uniformly and rapidly increasing in size. Sutures depressed, straight, radial. Umbilicus moderately broad. Aperture an interiomarginal, extraumbilical-umbilical, low arch bordered by well-developed portici. Wall calcareous perforate. Surface strongly rugose, becoming less rugose or hispid on final one or two chambers. Coiling predominantly dextral. Average maximum diameter 0.46 mm."
Entries in the Catalog of original descriptions: Hedbergella libyca, Hedbergella costellata
Character matrix
| test outline: | Lobate | chamber arrangement: | Trochospiral | edge view: | Inequally biconvex | aperture: | Umbilical-extraumbilical |
| sp chamber shape: | Globular | coiling axis: | Low | periphery: | N/A | aperture border: | Thick porticus |
| umb chbr shape: | Globular | umbilicus: | Wide | periph margin shape: | Broadly rounded | accessory apertures: | None |
| spiral sutures: | Moderately depressed | umb depth: | Deep | wall texture: | Finely muricate | shell porosity: | Finely Perforate: 1-2.5µm |
| umbilical or test sutures: | Moderately depressed | final-whorl chambers: | 5-7 | N.B. These characters are used for advanced search. N/A - not applicable | |||
Geological Range:
Last occurrence (top): within T. globotruncanoides zone (98.85-100.50Ma, top in Cenomanian stage). Data source: [copied from Chronos database]
First occurrence (base): within P. appenninica zone (100.50-101.92Ma, base in Albian stage). Data source: [copied from Chronos database]
Plot of range and occurrence data:
Barr, F. T. (1972a). Cretaceous biostratigraphy and planktonic foraminifera of Libya. Micropaleontology. 18(1): 1-46. gs Leckie, M. (1984). Mid-Cretaceous planktonic foraminiferal biostratigraphy off Central Morocco, Deep Sea Drilling Project Leg 79, Sites 545 and 547. Initial Reports of the Deep Sea Drilling Project. 79: 579-620. gs References:

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Paracostellagerina libyca compiled by the pforams@mikrotax project team viewed: 18-1-2026
Short stable page link: https://mikrotax.org/pforams/index.php?id=110380 Go to Archive.is to create a permanent copy of this page - citation notes |
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