Catalog - Proliferania

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.

Proliferania

Citation: Proliferania Georgescu 2010

Type species: Ventilabrella decoratissima de Klasz 1953

Tests with biserial chamber arrangement throughout in the primitive species. Evolved species with adult stage with multichamber growth, which begins with the biaperturate progressive chamber and continues with four to five multichamber sets; chamber number increases by one at an irregular rate in the successive multichamber sets. Sutures are depressed or with calyptoridges in primitive species and strong phaneroridges in evolved ones. Test compressed in edge view. Periphery is simple in the primitive species and with transverse and parallel keels resulting from the fusion of the phaneroridges across the periphery. Aperture is simple, a low to medium high arch in the biserial species and multiple in the multichamber growth adult stage. Early species ornamented with leptocostae tending to concentrate in the peripheral region, the evolved ones exhibit a smooth chamber surface; vestiges of the ancestral costate ornamentation may occur in the phaneroridges. Well-developed periapertural pustulose area. Test wall is calcitic, hyaline and perforate.

name is derived from the Latin verb proliferare (= to increase in number), with reference to the adult stage showing multichamber growth.

Remarks.– Proliferania and Sigalia evolved from the Planulitella sphenoides through divergent evolution. The first evolutionary occurrence of the two lineages in the DSDP Site 95 is in the lowermost part of the D. asymetrica Biozone (Sample 16-1, 99.5-101 cm). They exhibit relatively similar evolutionary trajectories in the development of (i) calyptoridges and phaneroridges over the sutures, (ii) adult stage with multiserial chamber growth, (iii) periphery with transverse keels and, in addition, ornamentation reduction over the chamber surface, resulting in strong similarities and rather minor morphological differences between them. The development of the adult stage with multichamber growth is abrupt in Proliferania (P. carpatica is completely biserial and P. decoratissima, its direct descendant, exhibits various degrees of chamber proliferation) and gradual in Sigalia (S. deflaensis exhibits incipient chamber proliferation in less than 15% of specimens, the dominant ones being biserial throughout); the loss of leptocostate ornamentation is early in Proliferania (biserial P. carpatica, which is also the last member of this directional lineage with biserial chamber arrangement, completely lost leptocostae over the chamber surface) and late in Sigalia (S. deflaensis, which is the earliest species of Sigalia with incipient chamber proliferation, has consistently developed leptocostae over all chambers); although most of the species of Proliferania and Sigalia have simple, circular to subcircular pores, vuggy pores ocassionally occurs only in the end species of the Proliferania directional lineage, namely P. decoratissima. Development of the adult stage with multichamber growth resulting in chamber proliferation occurred at different stratigraphical intervals, namely earlier in Proliferania and later in Sigalia; moreover, the stratigraphical ranges of the species with occasional or well-developed adult stage with multichamber growth in the two directional lineages do not overlap.

Species included.– Proliferania initialis – new species, P. carpatica (Samuel & Salaj, 1963) and P. decoratissima (de Klasz, 1953).

Stratigraphic range.– Santonian (D. asymetrica Biozone).

Geographic distribution.– Europe (Slovakia, Austria, Spain, France, Germany, Romania), northern Africa (Algeria, Tunisia), Middle East (Iraq, Israel), Gulf of Mexico, Caribbean region (Jamaica, Yucatan outer shelf) and west- ern South Atlantic Ocean (São Paolo Plateau, Rio Grande Rise) (Fig. 16).

References:

Georgescu, M. D. (2010d). Origin, taxonomic revision and evolutionary classification of the late Coniacian-early Campanian (Late Cretaceous) planktic foraminifera with multichamber growth in the adult stage. Revista Española de Micropaleontología. 42: 59-118. gs

CATALOG OF ORIGINAL DESCRIPTIONS: Proliferania Georgescu 2010

Proliferania

References:

Add Comment

Comments