Nannotax3 - ntax_cenozoic - Braarudosphaera bigelowii

Citation: Braarudosphaera bigelowii (Gran & Braarud 1935) Deflandre, 1947

Basionym: Pontosphaera bigelowii Gran & Braarud 1935

Synonyms:

Eodiscoaster danicus Martini 1961 [according to Martini 1971]
Braarudosphaera deflandrei Lecal-Schlauder 1949
Braarudosphaera deflandrei maroccana Lecal-Schlauder 1951
Chrysochromulina parkeae Green & Leadbater 1972 (non-calcifying life-cycle phase)

Variants:
sub-types within modern B. bigelowii:
Takano et al. (2006) and Hagino et al. (2009) showed that four different size clases of Braarudosphaera bigelowii could be recognised in modern populations from around Japan and five genotypes (based on single cell PCR amplification)

Small form; side length 1.5-2.5µm (diam 2.2-3.8µm); no genotype data
Intermediate form A; side-length 4.0-5.0µm (diam 6-7.5µm); Genotypes I & II.
Intermediate form B; side-length 5.3-7.0µm (diam 8-10.5); Genotype III.
Large form; side-length 7.5-8.5µm (diam 11-13µm); Genotypes IV & V.

NB Sizes quoted are side lengths of pentaliths to convert to lith diameter multiply by 1.5 to convert to coccosphere diameter mutliply by 3. Genotypes I & II and IV & V formed clusters supporting the morphological separation. The degree of separation between the genotype groups suggested that the morphotypes were well-diverged species. No consistent differences between the forms were seen apart from size. This scheme has also been supported by observations of Konno et al. (2007) and Fernando et al. (2013).

sub-types within Paleocene B. bigelowii
Criscione et al. (2017) convincingly demonstated the existence of two size morphotypes in populations of B. bigelowii of mid Paleocene age (NP4-5) from Zumaia in N. Spain.

form X 1.5-4.5µm
form Y 4.5-10.6 µm

Jones et al. (2021) studied the basal Danian (NP1) Braarudosphaera populations in detail, they found a similar range of specimen sizes but without convincing polymodality.

Possible preservational variants

Braarudosphaera rosa Levin & Joerger 1967 - lobate periphery, looks like poorly preserved B. bigelowii [my interpretation - JRY 2016]
Braarudosphaera irregularis Bybell & Gartner 1972 - irregular periphery, looks like poorly preserved B. bigelowii [my interpretation - JRY 2016]
Braarudosphaera cheloma Bybell & Gartner 1972 - notches at the end of sutures, may be a distinct species or a preservation form, described from M. Eocene [my interpretation - JRY 2016]
Micrantholithus concinnus Bramlette & Sullivan 1961 - segments extended along one edge to give rotated flower-like appearance. Looks distinctive but does not seem to have been recorded since original description so may be a preservational form. [my interpretation - JRY 2016]

Distinguishing features:
Parent taxon (Braarudosphaera): Pentaliths approximately pentagonal, sutures go to edges of pentagon.
This taxon: Pentaliths pentagonal with sraight edges and flat top surface

Coccospheres are regular pentagonal dodecahedra with the plates closely butting to form a continuous cover. Liths pentagonal, surface smooth, flat or gently concave. Sutures show clockwise obliquity in distal view, running from centre to approx 3/8 of the way along side of the pentalith.
Pentalith diameter varies from about 1.5 to 7µm but in single samples all pentaliths are usually of very similar size. It is likely that several pseudo-cryptic species occur within the modern B. bigelowii (Takano et al. 2006, Hagino 2009).

Neritic - predominanty observed in shelf seas, oceanic occurrences much rarer.

Hagino et al. (2013) have shown that the alternate life-cycle stage (Braarudosphaera bigelowii ALT) is a motile scale-bearing form previously described as Chrysochromulina parkeae Green & Leadbeater. The evidence includes that they have identical 18S rDNA sequences and both have a very unusual endosymbiotic nitrogen-fixing cyanobacterium UCYN-A.

Hagino et al. (2016) showed that biomineralisation is extra-cellular, and that the peatliths have significanly higher Mg than heterococcoliths.

Only recently cultured, despite numerous attempts, it is dificult to maintain and is not available currently (2019) from standard culture collections (J. Green, C. Klass, I. Probert, K. Hagino pers. coms.).

Molecular phylogeny (Hagino et al. 2009, 2013) proved that B. bigelowii is a haptophyte and paces it either basal to the coccolithophore clade or as a closely related clade. The biomineralisation mechanism is very different to that of coccolithophores clades so it should still be regarded as a nannolith-forming species.

Geological Range:
Last occurrence (top): Extant. Data source: present in the plankton (Young et al. 2003)
First occurrence (base): within Cenomanian Stage (93.90-100.50Ma, base in Cenomanian stage). Data source: Burnett 1998

References:

Bartol, M., Pavsic, J., Dobnikar, M. & Bernasconi, S. M. (2008). Unusual Braarudosphaera bigelowii and Micrantholithus vesper enrichment in the Early Miocene sediments from the Slovenian Corridor, a seaway linking the Central Paratethys and the Mediterranean. Palaeogeography Palaeoclimatology Palaeoecology. 267(1-2): 77-88. 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. (2010). Calcareous nannofossils from the Paleocene/Eocene Thermal Maximum interval of southern Tanzania (TDP Site 14). Journal of Nannoplankton Research. 31(1): 11-38. gs O

Bown, P. R. (2016). Paleocene calcareous nannofossils from Tanzania (TDP sites 19, 27 and 38). Journal of Nannoplankton Research. 36(1): 1-32. gs

Bown, P. R., Gibbs, S. J., Sheward, R., O’Dea, S. & Higgins, D. (2014). Searching for cells: the potential of fossil coccospheres in coccolithophore research. Journal of Nannoplankton Research. 34(S): 5-21. gs

Bramlette, M. N. & Sullivan, F. R. (1961). Coccolithophorids and related nannoplankton of the Early Tertiary in California. Micropaleontology. 7(2): 129-188. gs

Burnett, J. A. (1998). Upper Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 132-199. gs O

Bybell, L. M. & Gartner, S. (1972). Provincialism among mid-Eocene calcareous nannofossils. Micropaleontology. 18(319-336): -. gs

Bybell, L. (1975). Middle Eocene calcareous nannofossils at Little Stave Creek, Alabama. Tulane Studies in Geology and Paleontology. 11(4): 177-247. gs O

Criscione, J., Bord, D., Godfery, L. & Aubry, M. -P. (2017). Inferred pseudo-cryptic speciation in the coccolithophore species Braarudosphaera bigelowii (Gran and Braarud) during the Early Paleocene (Danian). Marine Micropaleontology. 137: 1-15. gs

de Kaenel, E. & Villa, G. (1996). Oligocene-Miocene calcareous nannofossil biostratigraphy and paleoeecology from the Iberian Abyssal Plain. Proceedings of the Ocean Drilling Program, Scientific Results. 149: 79-145. gs O

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

Dunkley Jones, T., Bown, P. R. & Pearson, P. (2009). Exceptionally well preserved upper Eocene to lower Oligocene calcareous nannofossils (Prymnesiophycidae) from the Pande Formation (Kilwa Group), Tanzania. Journal of Systematic Palaeontology. 7(4): 359-411. gs

Fernando, A. G. S., Fernandez, A. R. C. & Wiesner, M. G. (2013). Braarudosphaera bigelowii morphotypes in the surface sediments of the southwestern South China Sea. Micropaleontology. 59(6): 579-586. gs

Gran, H. H. & Braarud, T. (1935). A quantitative study of the phytoplankton in the Bay of Fundy and the Gulf of Maine (including observations on hydrography, chemistry and turbidity). Journal of the Biological Board of Canada. 1: 279-467. gs

Hagino, K., Takano, Y. & Horiguchi, T. (2009). Pseudo-cryptic speciation in Braarudosphaera bigelowii (Gran and Braarud) Deflandre. Marine Micropaleontology. 72: 210-221. gs

Hagino, K., Onuma, R., Kawachi, M. & Horiguchi, T. (2013). Discovery of an Endosymbiotic Nitrogen-Fixing Cyanobacterium UCYN-A in Braarudosphaera bigelowii (Prymnesiophyceae). PLoS One. 8(12): 1-11. gs

Hagino, K., Tomioka, N., Young, J. R., Takano, Y., Onuma, R. & Horiguchi, T. (2016). Extracellular calcification of Braarudosphaera bigelowii deduced from electron microscopic observations of cell surface structure and elemental composition of pentaliths. Marine Micropaleontology. 125(1): 85-94. gs

Jones, A. P. & Dunkley Jones, T. (2020). Middle Eocene to Early Oligocene calcareous nannofossils from the Nanggulan Formation, Java, Indonesia. Journal of Nannoplankton Research. 38(1): 57-79. gs

Jones, H. L., Scrobola, Z. & Bralower. T. J. (2021). Size and shape variation in the calcareous nannoplankton genus Braarudosphaera following the Cretaceous/Paleogene (K/Pg) mass extinction: clues as to its evolutionary success. Paleobiology. 1-24. gs

Konno, S., Harada, N., Narita, H. & Jordan, R. W. (2007). Living Braarudosphaera bigelowii (Gran & Braarud) Deflandre in the Bering Sea. Journal of Nannoplankton Research. 29(2): 78-87. gs

Lecal-Schlauder, J. (1949). Notes preliminaires sur les coccolithophorides d'Afrique duNord. Bulletin de la Société d'Histoire Naturelle de l'Afrique du Nord. 4-(5-6): 160-167. gs

Lecal-Schlauder, J. (1951). Recherches morphologiques et biologiques sur les Coccolithophorides Nord-Africains. Annales de l'Institut Océanographique, Monaco & Paris. 26: 255-362. gs

Levin, H. L. & Joerger, A. P. (1967). Calcareous nannoplankton from the Tertiary of Alabama. Micropaleontology. 13(2): 163-182. gs

Mai, H. (2001). New coccolithophorid taxa fom the Guelhemmerberg airshaft. Lower Paleocene, The Netherlands. Micropaleontology. 47: 144-154. gs

Mai, H., von Salis, K., Willems, H. & Romein, A. J. T. (1997). Fossil coccospheres from the K/T boundary section from Geulhemmerberg, The Netherlands. Micropaleontology. 43: 281-303. gs

Martini, E. (1961). Nannoplankton aus dem Tertiär und der obersten Kreide von SW-Frankreich. Senckenbergiana Lethaea. 42: 1-32. gs

Martini, E. (1971). Die Typen und Typoide des Natur-Museums Senckenberg, 46): Fossiles Nannoplankton. Senckenbergiana Lethaea. 52: 115-127. gs

Okada, H. & Thierstein, H. R. (1979). Calcareous nannoplankton - Leg 43, Deep Sea Drilling Project. Initial Reports of the Deep Sea Drilling Project. 43: 507-573. gs O

Romein, A. J. T., Willems, H. & Mai, H. (1996). Calcareous nannoplankton of the Geulhemmerberg K/T boundary section, Maastrichtian type area, the Netherlands. Geologie en Mijnbouw. 75: 231-238. gs

Salomon, R. (1999). The Calcite Palace. Website - https://ina.tmsoc.org/galleries/CalcitePalace/index.htm. -. gs

Self-Trail, J. (2011). Paleogene Calcareous Nannofossils of the South Dover Bridge core, Southern Maryland (USA). Journal of Nannoplankton Research. 32(1): 1-28. 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. gs

Thomsen, H. A. (2016). Baltic Sea coccolithophores – an overview of insights into their taxonomy and ecology from the last 40 years. Journal of Nannoplankton Research. 36(2): 97-119. gs O

Young, J. R. (1998). Neogene. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 225-265. gs

Young, J. R., Geisen, M., Cros, L., Kleijne, A., Probert, I. & Ostergaard, J. B. (2003). A guide to extant coccolithophore taxonomy. Journal of Nannoplankton Research. S1: 1-132. gs

Braarudosphaera bigelowii

References:

Comments (0)

Add Comment