Catalog - Asymetria Catalog - Asymetria


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 -> A -> Asymetria
Other pages this level: Abathomphaloidea, Abathomphalus, Acarinina, Alanlordella, Alicantina, Alloglobigerinoides, Anaticinella, Anomalina, Archaeoglobigerina, Archaeoglobitruncana, Archaeoguembelitria, Aristerospira, Ascoliella, Astrorotalia, Asymetria

Asymetria asymetrica Georgescu 2012


Citation: Asymetria Georgescu 2012
taxonomic rank: Genus
Type specimens: Holotype. Specimen WKB 010110. Paratypes. Five specimens, WKB 010111-010115.
Type age (chronostrat): Upper Albian-lowermost Cenomanian
Type locality: Upper Albian-lowermost Cenomanian (from the P. ticinensis Biozone to the lowermost part of the T. globotruncanoides Biozone). An uncertain occurrence in the early late Albian P. subticinensis Biozone at DSDP Site 398 is based on one poorly preserved specimen.
Type repository: Willi Karl Braun Micropaleontological Collection at the University of Calgary (Calgary, Alberta, Canada)

Current identification:

Original Description

Type species.- Asymetria asymetrica – new species. Species included. IS or FDS: Asymetria asymetrica – new.

Diagnosis.  Schackoinid  planktic  foraminifera  with  low  trochospiral  test,  last-formed chambers with one distal bulbous projection, and asymmetrically developed ornamentation:smooth on the spiral side and pustulose on the umbilical one.

Description. Test is low trochospiral; earlier chambers are globular, then reniform; the last-formed one to three is radially elongate and bears one distal bulbous projection. Sutures are distinct, depressed, and straight to slightly curved on both test sides. Test is convex- concave, slightly asymmetrical in edge view. Aperture is a medium high arch, extraumbilical- peripheral in position and bordered by a wide, tunnel-shaped lip; relict periapertural structures occur in the umbilical region. Chamber surface exhibits asymmetrically developed ornamentation; pustulose ornamentation is developed only on the umbilical side, whereas the spiral side is smooth. Test wall is calcitic, hyaline, simple and perforate; pores are simple, and with circular outline.

The name invokes the asymmetrical ornamentation.

Extra details from original publication
Remarks. Asymetria differs from any other Cretaceous planktic foraminifer by the asymmetrically developed ornamentation, which is pustulose on the umbilical side, and smooth on the spiral side.


Georgescu, M. D. (2012b). Morphology, taxonomy, stratigraphic distribution and evolutionary classification of the schackoinid planktic foraminifera (late Albian- Maastrichtian, Cretaceous). In, Bailey, D. R. , Howard, S. E. , (ed.) Deep-sea marine biology, geology, and human impact. Nova Publishers, New York 1-62. gs


Asymetria compiled by the pforams@mikrotax project team viewed: 25-2-2024

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