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.
|Prosphaeroidinella parkerae Ujiie 1976|
|Prosphaeroidinella valleriae Brönnimann, Whittaker & Parisi 1988|
Current identification/main database link: Sphaeroidinellopsis Banner & Blow, 1959
Another species also belonging to Prosphaeroidinella, P. parkerae Ujiie, shows much more widely spaced framework of honey-comb structure. The frame is distinctly larger than that of normal species of Globigerinoides and solely comparable sized frame can be recognized at the outer face of an inner layer (designated as Layer 2 in tf. I) of wall in Sphaeroidinellopsis or Sphaeroidinella. The outer layer (Layer 3) is so-called cortex layer, whose outer surface is quite smooth paved by the calcite basal planes. The smoothness corresponds to that at the inner surface of wall. These facts imply some essential difference in genesis between the two types of layer. As will be discussed and inferred in Remarks on the species, the inner layer may be a fundamental constituent of wall in Sphaeroidinellopsis or Sphaeroidinella, while the outer cortex layer may be secondary but advanced component characteristic to the genera. Therefore, I suppose that the wall structure peculiar to P. parkerae Ujiie may not have been resulted from such a peeling-out of outer Layer 2 of Sphaeroidinellopsis or Sphaeroidinella through certain chemical dissolution or physical process (e. g., some vibration effect during the maceration of sediment samples) as Parker (1967) thought previously, but it may represent a kind of atavism. In this respect, the species must belong to the genus Prosphaeroidinella, although there is necessity to consider the phylogenetic difference between P. parkerae Ujiie and P. disjuncta (Finlay).
The present supposition from taxonomic views of the two species seems to be substantiated by their stratigraphic occurrences. Last appearance of P. disjuncta is followed immediately by the initial appearance of rather primitive but real Sphaeroidinellopsis species at the boundary between the N. 12 and N. 13 of Blow's (1969) zones, whereas P. parkerae Ujiie occurs concurrently with well-developed Sphaeroidinellopsis and with Pliocene species of Sphaeroidinella.
Extra details from original publication
Fordham, B. G. (1986). Miocene-Pleistocene planktic foraminifers from D.S.D.P. Sites 208 and 77, and phylogeny and classification of Cenozoic species. Queensland, Australia. 1-224. gs Ujiie, H. (1976). Prosphaeroidinella, n. gen.: Probable ancestral taxon of Sphaeroidinellopsis (Foraminifera). Bulletin of the national Science Museum, Tokyo. 2(1): 9-26. gs
Fordham, B. G. (1986). Miocene-Pleistocene planktic foraminifers from D.S.D.P. Sites 208 and 77, and phylogeny and classification of Cenozoic species. Queensland, Australia. 1-224. gs
Ujiie, H. (1976). Prosphaeroidinella, n. gen.: Probable ancestral taxon of Sphaeroidinellopsis (Foraminifera). Bulletin of the national Science Museum, Tokyo. 2(1): 9-26. gs
Prosphaeroidinella compiled by the pforams@mikrotax project team viewed: 25-9-2022
Short stable page link: https://mikrotax.org/pforams/index.php?id=132035 Go to Archive.is to create a permanent copy of this page - citation notes