Protentella sp. Specimens which cannot be assigned to established species
Taxonomy
Citation: Protentella Lipps 1964Taxonomic rank: genusType species: Protentella prolixa Lipps 1964Taxonomic discussion: Blow (1965) considered Protentella to be a junior synonym of Bolliella Banner and Blow and further suggested that Protentella prolixa, the type species, may be a junior synonym of Bolliella adamsi. Surface ultrastructural studies by Srinivasan and Kennett (1975) of these forms indicate that Protentella prolixa lacks spine bases and the hispid test surface characteristic of Bolliella, but,on the other hand, it has a cancellate pattern of steeply rising ridges (Pl. 55, Fig. 1) as in Clavatorella and Globorotaloides. Similarities in surface ultrastructure among Protentella, Clavatorella, and Globorotaloides suggest that they are phylogenetically closely related. [Kennett & Srinivisan 1983]
Distinguishing features: Parent taxon (Globigerinidae): Wall spinose, usually with 3½-6 globular chambers in final whorl, trochospiral or planispiral This taxon: Like Globigerinella but adult chambers radially elongate. (Late Miocene - Pliocene)
NB These concise distinguishing features statements are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus. They are being edited as the site is developed and comments on them are especially welcome.
Description
Diagnostic characters: Protentella is characterized by an initial trochospiral test, followed by a tendency to become planispiral, and radially elongate adult chambers. The surface ultrastructure is characterized by regular reticulate pattern of ridges forming deep subhexagonal pore pits. [Kennett & Srinivisan 1983]
Biogeography and Palaeobiology
Phylogenetic relationsProtentella evolved from Clavatorella in the Middle Miocene, which in turn descended from Globorotaloides hexagona [Kennett & Srinivisan 1983]
Most likely ancestor: Globigerinella - at confidence level 2 (out of 5). Data source: Aze et al. 2011 [but Kennett & Srinivasan 1989 suggest origin from Clavatorella].
Biostratigraphic distribution
Geological Range: Last occurrence (top): at top of N19 zone (100% up, 4.4Ma, in Zanclean stage). Data source: Total of ranges of the species in this database First occurrence (base): within N12 zone (11.79-13.41Ma, base in Serravallian stage). Data source: Total of ranges of species in this database
Plot of occurrence data:
Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
Primary source for this page: Kennett & Srinivasan 1983, p.222
References:
Blow, W. H. (1965). Clavatorella, a new genus of the Globorotaliidae. Micropaleontology. 11(3): 365-368. gs
Kennett, J. P. & Srinivasan, M. S. (1983). Neogene Planktonic Foraminifera. Hutchinson Ross Publishing Co., Stroudsburg, Pennsylvania. 1-265. gs
Lipps, J. H. (1964). Miocene planktonic foraminifera from Newport Bay, California. Tulane Studies in Geology and Paleontology. 2: 109-133. gsO
Srinivasan, M. S. & Kennett, J. P. (1975c). The status of Bolliella, Beella, Protentella and related planktonic foraminifera based on surface ultrastructure. Journal of Foraminiferal Research. 5(3): 155-165. gs
Protentella compiled by the pforams@mikrotax project teamviewed: 23-4-2026