Daughter taxa (time control age-window is: 0-800Ma)![]() | Granddaughter taxa | ||||
![]() | Braarudosphaera Pentaliths approximately pentagonal, sutures go to edges of pentagon. | ||||
![]() | ![]() | ![]() | Hexadelus Thin nannoliths similar to Braarudosphaera but with 6 segments - usually occur as isolated segments | ||
![]() | ![]() | ![]() | ![]() | Micrantholithus Pentaliths with sutures emerging through corners; edge often indented giving stellate outline | M. breviradiatus M. disculus M. flos M. astrum M. entaster M. excelsus M. hebecuspis M. minimus M. pinguis M. vesper M. attenuatus M. mirabilis M. angulosus M. bramlettei M. bulbosus M. crenulatus M. tinus M. sp. |
![]() | ![]() | ![]() | ![]() | Pemma Pentaliths with a central depression/perforation in each segment; often producing elevated, robust structures that are commonly observed in side view. | |
Pentaster |
Taxonomy:
Affinities: Braarudosphaera was long considered a group of highly uncertain affinities and possibly dinoflagellates, but recent molecular genetic data (Takano et al. 2006) has shown that they occupy a basal position within the coccolithophore clade, and so are definitely haptophytes and probably derived in some way from coccolithophores.
Distinguishing features:
Parent taxon (Braarudosphaerales): 2N(?) cell covered by pentaliths (plates formed of 5 segments with lamellar sub-structure) formed extracellualrly
N: cell motile, covered by scales
This taxon: Coccospheres pentagonal dodecahedra formed of five pentagonal plates
Farinacci & Howe catalog pages: Braarudosphaeraceae [no catalog entry yet]
Morphology:
Pentalith morphology: Pentaliths consist of five segments, each of which behaves as a discrete crystal-unit with c-axis parallel to edge of the pentalith. A lamellar substructure to the segments is consistently present.
Size:
Ecology & Biogeography: Predominantly neritic both at the present day and in the fossil record.
Tags | LITHS: |
Metrics | Lith size: 2->30µm; Segments: 5->5; |
Geological Range:
Last occurrence (top): Extant. Data source: Total of range of species in this database
First occurrence (base): at base of Cenomanian Stage (0% up, 100.5Ma, in Albian stage). Data source: Total of range of species in this database
Plot of occurrence data:
Aubry, M. -P. (1989a). Handbook of Cenozoic calcareous nannoplankton. Book 3: Ortholithae (Pentaliths, and others), Heliotithae (Fasciculiths, Sphenoliths and others). Micropaleontology Press, American Museum of Natural History, New York. 1-279. gs Bown, P. R. (2005d). Palaeogene calcareous nannofossils from the Kilwa and Lindi areas of coastal Tanzania (Tanzania Drilling Project 2003-4). Journal of Nannoplankton Research. 27(1): 21-95. gs O Bown, P. R., Rutledge, D. C., Crux, J. A. & Gallagher, L. T. (1998). Early Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 86-131. gs Deflandre, G. (1947a). Braarudosphaera nov. gen., type d'une famille nouvelle de Coccolithophorides actuels a elements composites. Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences, Paris. 225: 439-441. gs V O Kelly, D. C., Norris, R. D. & Zachos, J. C. (2003). Deciphering the paleoceanographic signi¢cance of Early Oligocene Braarudosphaera chalks in the South Atlantic. Marine Micropaleontology. 49: 49-63. gs Lefort, F. (1972). Quelques caracteres morphologiques de deux especes actuelles de Braarudosphaera (Chrysophycees, Coccolithophoracees). Botaniste. 20(3): 13-. gs V O Liebrand, D. et al. (2018). Orbitally forced hyperstratification of the Oligocene South Atlantic Ocean. Paleoceanography and Paleoclimatology. 33: 511-529. gs Peleo-Alampay, A. M., Mead, G. A. & Wei, W. (1999). Unusual Oligocene Braarudosphaera-rich layers of the South Atlantic and their palaeoceanograpghic implications. Journal of Nannoplankton Research. 21(1): 17-26. gs V O Perch-Nielsen, K. (1985a). Cenozoic calcareous nannofossils. In, Bolli, H. M., Saunders, J. B. & Perch-Nielsen, K. (eds) Plankton Stratigraphy. Cambridge University Press, Cambridge 427-555. gs Perch-Nielsen, K. (1985b). Mesozoic calcareous nannofossils. In, Bolli, H. M., Saunders, J. B. & Perch-Nielsen, K. (eds) Plankton Stratigraphy. Cambridge University Press, Cambridge 329-426. gs Takano, Y., Hagino, K., Tanaka, Y., Horiguchi, T. & Okada, H. (2006). Phylogenetic affinities of an enigmatic nannoplankton, Braarudosphaera bigelowii based on the SSU rDNA sequences. Marine Micropaleontology. 60: 145-156. gsReferences:
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Braarudosphaeraceae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 24-5-2022
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=155 Go to Archive.is to create a permanent copy of this page - citation notes |
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