Nannotax3 - ntax_mesozoic - Tubodiscus burnettiae

Distinguishing features:
Parent taxon (Tubodiscus): Tubodiscids with high and birefringent proximal collar cycle and wide central-area. Rim image is clearly bicyclic in XPL.
This taxon: Medium to large (5-10 µm), typically broadly elliptical; the central area is broad (usually greater than the width of the rim). Inner and outer rim cycles of similar width.

Citation: Tubodiscus burnettiae Bown in Kennedy et al., 2000

A large (c. 7.5 µm), typically broadly elliptical species of Tubodiscus with two distinct rim cycles, the outermost cycle is dark and often slightly broader, the inner cycle displays white interference colours; the central area is broad (usually greater than the width of the rim) and no central structures have been observed.

Geological Range:
Last occurrence (top): within Albian Stage (100.50-113.20Ma, top in Albian stage). Data source: Kennedy et al. 2000
First occurrence (base): within Valanginian Stage (132.60-137.70Ma, base in Valanginian stage). Data source: Kennedy et al. 2000

References:

Aguado, R. et al. (2018). A new record of the Weissert episode from the Valanginian succession of Cehegín (Subbetic, SE Spain): bio- and carbon isotope stratigraphy. Cretaceous Research. 92: 122-137. gs

Applegate, J. L. & Bergen, J. A. (1988). Cretaceous calcareous nannofossil biostratigraphy of sediments recovered from the Galicia Margin, ODP Leg 103. Proceedings of the Ocean Drilling Program, Scientific Results. 103: 293-348. gs O

Bown, P. R. (2001). Calcareous nannofossils of the Gault, Upper Greensand and Glauconitic Marl (Middle Albian-Lower Cenomanian) from the BGS Selborne boreholes, Hampshire. Proceedings of the Geologists' Association. 112: 223-236. gs

Bown, P. R. (2005c). Early to Mid-Cretaceous Calcareous Nannoplankton from the Northwest Pacific Ocean, Leg 198, Shatsky Rise. Proceedings of the Ocean Drilling Program, Scientific Results. 198: 1-82. gs O

Gale, A. S. et al. (2011). The uppermost Middle and Upper Albian succession at the Col de Palluel, Hautes-Alpes, France: An integrated study (ammonites, inoceramid bivalves, planktonic foraminifera, nannofossils, geochemistry, stable oxygen and carbon isotopes, cyclostratigraphy). Cretaceous Research. 32: 59-130. gs

Kanungo, S., Bown, P. R. & Gale, A. S. (2020). Cretaceous (Albian-Turonian) calcareous nannofossil biostratigraphy of the onshore Cauvery Basin, southeastern India. Cretaceous Research. 118 [2021]: 1-22. gs

Kennedy, W. J. et al. (2000). Integrated stratigraphy across the Aptian-Albian boundary in the Marnes Bleues, at the Col de Pre _-Guittard, Arnayon (Drome), and at Tartonne (Alpes-de-Haute-Provence), France: a candidate Global Boundary Stratotype Section and Boundary Point for the base of the Albian Stage. Cretaceous Research. 21: 591-720. gs

Püttmann, T., Mutterlose, J., Kaplan, U. & Scheer, U. (2019). Reworking of Cenomanian ammonites decoded by calcareous nannofossils (southern Münsterland Basin, northwest Germany). Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 291(1): 1-17. gs