Catalog - Helvetiella helvetia

CATALOG OF ORIGINAL DESCRIPTIONS: Helvetiella helvetia Longoria and Gamper 1984

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.


Higher levels: pf_cat -> H -> Helvetiella -> Helvetiella helvetia
Other pages this level: H. atlantica, H. helvetia

Helvetiella helvetia

Citation: Helvetiella helvetia Longoria and Gamper 1984
Rank: Species
Described on page(s) : 174-5
Type specimens: pl. 1, figs. 1-3, 10, 13, 14: Figs. 1, 2, holotype, observe high trochospiral side and heavily ornamented test, maximum diameter 421 µm; 3, paratype, maximum diameter 310 µm; 10, paratype, note low trochospire, maximum diameter 430 µm; 13, 14, paratype showing well-developed spiral system of tegilla and enlargement of umbilical apparatus showing infra- and intralaminar apertures, maximum diameter 410 µm.
Type sample (& lithostrat): DSDP Leg 32 111A-11-6 120-122cm
Type age (chronostrat): Upper Maastrichtian
Type locality: NW Atlantic, Orphan Knoll at the edge of the continental rise northeast of Newfoundland. lat. 50°25.57' N., long. 46°22.05' W.
Type repository: USNM

Current identification:


Original Description

Diagnosis: Helvetiella with biconvex test, spiro-convex; five to six chambers in last whorl, increasing gradually in size as added, umbilicus dip [sic].

Description: Test medium size, strongly lobulate, biconvex; spiral side strongly convex. Early whorls inflated, final whorl formed by four to five globular chambers, final chamber often smaller than penultimate chamber. Sutures strongly depressed, straight on both spiral and umbilical ides. Umbilicus of medium size, deep, covered by tegilla.

Size:

Etymology:
Helvetiella helvetia is named for Switzerland, to honor its geologists and their pioneer contributions to Cretaceous planktonic foraminiferal biostratigraphy.

Extra details from original publication
Remarks.- Helvetiella helvetia is characterized by its biconvex test, with five to six globular chambers in the last whorl. These features distinguish it from H. atlantica Longoria and Gamper, 1984.

Variation of the species: More than 60 specimens of Helvetiella helvetia were analyzed. The diagnostic features outlined above are constant. The last chamber is often smaller than the penultimate chamber. A few specimens tend to develop a lower trochospire (fig. 10); typical forms, however, display a high spiral side.

Range: Late Maastrichtian. Restricted to the Abathomphalus mayaroensis/Globigerina eugubina lnterval Zone.

Editors' Notes

References:

Longoria, J. F. & Gamper, M. A. (1984). Subfamily Helvetiellinae, a new group of Late Cretaceous (Maastrichtian) planktonic foraminifera. Micropaleontology. 30: 171-179. gs


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Helvetiella helvetia compiled by the pforams@mikrotax project team viewed: 5-12-2022

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