Chambers elongate, in adult specimens
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Low to medium trochospiral, lobulate periphery; wall smooth
Specimens which cannot be assigned to established species
| Daughter taxa (time control age-window is: 0-800Ma) | ||||
| | | Beella digitata Chambers elongate, in adult specimens | |
| | | Beella praedigitata Low to medium trochospiral, lobulate periphery; wall smooth | |
| Beella sp. Specimens which cannot be assigned to established species | ||||
In general, the surface ultrastructure of Beella is similar to but much finer than that of Globigerina (Gg.) bulloides (Srinivasan and Kennett, 1975). Although Parker (1962) noted its close affinity with Globigerina, she suggested that Beella may well be referred to Hastigerinella. Lipps (1966) considered Beella as a synonym of Globigerina. Banner and Blow (1960) regarded Beella as a subgenus of Globorotalia, but later Blow (1969) considered it as a subgenus of Globigerina.
We agree with Loeblich and Tappan (1964) that Beella is more closely related to Globigerina, but its radially elongate chambers, relatively finer surface ultrastructure, and a restricted stratigraphic occurrence justify generic rank to Beella. [Kennett & Srinivasan 1983]
Catalog entries: Beella
Distinguishing features:
Parent taxon (Globigerinidae): Wall spinose, usually with 3½-6 globular chambers in final whorl, trochospiral or planispiral
This taxon: Digitate chambers:
Most likely ancestor: Globigerinella - at confidence level 3 (out of 5). Data source: molecular genetic data - see Beella praedigitata for details.
Geological Range:
Last occurrence (top): Extant. Data source: Total of ranges of the species in this database
First occurrence (base): within N17a zone (6.60-8.58Ma, base in Tortonian stage). Data source: Total of ranges of species in this database
Plot of occurrence data:
Primary source for this page: Kennett & Srinivasan 1983, p.230
Banner, F. T. & Blow, W. H. (1960b). The taxonomy, morphology and affinities of the genera included in the subfamily Hastigerininae. Micropaleontology. 6(1): 19-31. gs Blow, W. H. (1969). Late middle Eocene to Recent planktonic foraminiferal biostratigraphy. In, Bronnimann, P. & Renz, H. H. (eds) Proceedings of the First International Conference on Planktonic Microfossils, Geneva, 1967. E J Brill, Leiden 380-381. gs Kennett, J. P. & Srinivasan, M. S. (1983). Neogene Planktonic Foraminifera. Hutchinson Ross Publishing Co., Stroudsburg, Pennsylvania. 1-265. gs Lipps, J. H. (1966). Wall structure, systematics and phylogeny of Cenozoic planktonic foraminifera. Journal of Paleontology. 40(6): 1257-1274. gs Loeblich, A. R. & Tappan, H. (1964b). Sarcodina, Chiefly "Thecamoebians" and Foraminiferida. In, Moore, R. C. (ed.) Treatise on Invertebrate Paleontology, Protista 2, pt. C. University of Kansas Press, Lawrence 1-900. gs Parker, F. L. (1962). Planktonic foraminiferal species in Pacific sediments. Micropaleontology. 8(2): 219-254. gs 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. gsReferences:
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Beella compiled by the pforams@mikrotax project team viewed: 13-10-2024
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