CATALOG OF ORIGINAL DESCRIPTIONS: Praeplanctonia Georgescu 2009
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.
Citation: Praeplanctonia Georgescu 2009Rank: GenusType species: Praeplanctonia globiferaType age (chronostrat): Upper Albian (from the P.ticinensis Biozone throughout the P. appenninica Biozone)Type locality: Western North Atlantic Ocean (Blake Plateau), Eastern North Atlantic Ocean (offshore Cape Bojador, Spanish Sahara) and Caribbean region (Trinidad).
Current identification:
Original Description
Diagnosis.– Test biserial throughout or with a short triserial juvenile stage and biserial in the adult; aperture sub- terminal bordered by a short rim and provided with a toothplate; apertural face with supplementary suture; chamber surface smooth.
Description.– Test twisted, biserial throughout or with an early triserial stage and biserial in the adult. Chambers are globular to subglobular, overlapping at various rates. Sutures are distinct and depressed. Aperture subcircular and subterminal in position and bears a toothplate and is bor- dered by an asymmetrical rim. A supplementary suture is present on the apertural face, which connects the aper- ture base with the suture between the penultimate and last-formed chamber. Chamber surface is smooth. Test wall is calcitic, hyaline and nannoperforate; pore shape is elongate to circular.
Size: Etymology: The name suggests that this genus is ancestral to the planktic foraminifera with serial chamber arrangement. Extra details from original publication Remarks.– Praeplanctonia nov. gen. is characterized by high variability of the morphological features. The test may have an early triserial stage, becoming biserial when adult or is biserial throughout; the triserial-biserial tests present general resemblances with some Neobulimina Cushman & Wickenden, 1928 species of the late Albian, such as N. irregularis (Cushman & Parker, 1936), N. numerosa (Vasilenko, 1961), N. vridhachalensis (Rasheed & Govindan, 1968) and N. canadensis var. beta (Mello,1969). By contrast to Neobulimina, has twisted tests and therefore can be considered morphologically closer to Cassidella Hofker, 1951 and Fursenkoina Loeblich & Tappan, 1961. Praeplanctonia differs from these two in having an early triserial stage, which is occasionally developed, subterminal aperture rather than situated at the base of the last-formed chamber and the presence of the supplementary suture on the apertural face. Editors' Notes
References:
Georgescu, M. D. (2009a). On the origins of Superfamily Heterohelicacea Cushman, 1927 and the polyphyletic nature of planktic foraminifera. Revista Española de Micropaleontología. 41: 107-144. gsVO
Praeplanctonia compiled by the pforams@mikrotax project teamviewed: 8-12-2022
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