pforams@mikrotax - Hedbergella compacta pforams@mikrotax - Hedbergella compacta

Hedbergella compacta


Classification: pf_mesozoic -> Hedbergellidae -> Hedbergella -> Hedbergella compacta
Sister taxa: H. aptiana, H. bizonae, H. bollii, H. compacta, H. excelsa, H. gorbachikae, H. handousi, H. hexacamerata, H. hispaniae, H. infracretacea, H. kuhryi, H. kuznetsovae, H. labocaensis, H. luterbacheri, H. maslakovae, H. mitra, H. modesta, H. occulta, H. praelippa> >>

Taxonomy

Citation: Hedbergella compacta (Banner, Copestake & White, 1993)
taxonomic rank: Species
Basionym: Praehedbergella sigali compacta

Type images:

Original description:
DIAGNOSIS. A subspecies of P. sigali (Moullade) sensu lato, characterized by chambers which (sometimes excluding the final chamber) become depressed in the last whorl and have heights about half their lengths (when viewed from the spiral side), by relatively shallow intercameral sutures, which form intercameral angles of about 150° at the test periphery, and by a 'compact' test outline.
DESCRIPTION. Test about 0.10-0.15 mm at its maximum diameter, comprising about two whorls, each with 4l!2 cham- bers coiled in a low trochospire. The spiral side is almost flat or slightly convex. The depressions of intercameral sutures at the periphery of the test form angles of about 150° between adjacent chambers. The chambers themselves are symmetri- cal and increase in size gradually with growth and become depressed, being almost half as high as long when viewed on the spiral side (excluding the final chamber); the final cham- ber is only slightly lower than long. The umbilicus measures about 0.02 mm in diameter, and the aperture is a narrow slit with a narrow porticus. Perforation cones are not present.

Entries in the Catalog of original descriptions: Praehedbergella sigali compacta

Character matrix
test outline:chamber arrangement:Trochospiraledge view:aperture:
sp chamber shape:coiling axis:periphery:N/Aaperture border:
umb chbr shape:umbilicus:periph margin shape:accessory apertures:
spiral sutures:umb depth:wall texture:shell porosity:
umbilical or test sutures:final-whorl chambers:4-4.5 N.B. These characters are used for advanced search. N/A - not applicable

Geological Range:
Last occurrence (top): in lower part of Barremian Stage (40% up, 124.5Ma, in Barremian stage). Data source:
First occurrence (base): in lower part of Barremian Stage (35% up, 124.7Ma, in Barremian stage). Data source:

Plot of range and occurrence data:

References:

Banner, F. T., Copestake, P. & White, M. R. (1993). Barremian-Aptian Praehedbergellidae of the North Sea area: a reconnaisance. Bulletin of the Natural History Museum, London (Geology). 49: 1-30. gs


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Hedbergella compacta compiled by the pforams@mikrotax project team viewed: 18-7-2024

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Short stable page link: https://mikrotax.org/pforams/index.php?id=110240 Go to Archive.is to create a permanent copy of this page - citation notes



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