Velonalithus rioi

(Olafsson, 1989) Varol, n. comb. Sep 06, 2020

Set number: 252

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Velonalithus rioi, Middle Miocene, DSDP Leg 25, Site 242, Mozambique Channel (Davie Ridge), Indian Ocean

Set number: 255

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10µm

in mobile mount

Velonalithus , Middle Miocene, ODP Leg 154, Site 925C, Ceara Rise, Equatorial Atlantic Ocean

in mobile mount

Set number: 256

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10µm

in mobile mount

Velonalithus rioi, Middle Miocene, DSDP Leg 25, Site 242, Mozambique Channel (Davie Ridge), Indian Ocean

in mobile

Set number: 782

Fig. 1 size=11.0µm/9.2µm; Fig. 2 size 16.7µm; Fig. 3 size=14.0µm; Fig. 4 size=18.4µm; Fig. 5 size=13.5µm; Fig. 6 size=15.4µm; Fig. 8 size=12.2µm; Fig. 8 size=13.0µm; Fig. 9 size=15.8µm; Fig. 10 size=16.7µm

Velonalithus rioi, Middle Miocene, Malta

Final Epithet

Velonalithus rioi (Olafsson, 1989) Varol, n. comb.

Basionym

Triquetrorhabdulus rioensis Olafsson, 1989

Synonyms

Orthorhabdus rioi (Olafsson, 1989) Young & Bown, 2014

Description

Elongate needle-like nannolith with pointed ends. If the specimens rotated along the short axis, it appears birefringent in a particular orientation with a tangential c-axis but non-birefringent in the other orientation with a vertical c-axis (parallel to the microscope's axis). This indicates a complex arrangement of blades?/surfaces.

References

Bramlette, M. N. & Wilcoxon, J. A., (1967): Middle Tertiary calcareous nannoplankton of the Cipero section, Trinidad, W.I. - Tulane Studies in Geology and Paleontology. 5: 93-131.

Martini, E., (1965): Mid-Tertiary calcareous nannoplankton from Pacific deep-sea cores. - Colston Papers. 17: 393-411.

Olafsson, G., (1989): Quantitative calcareous nannofossil biostratigraphy of upper Oligocene to middle Miocene sediment from ODP Hole 667A and middle Miocene sediment from DSDP Site 574. - Proceedings of the Ocean Drilling Program, Scientific Results. 108: 9-22.

Young, J. R. & Bown, P. R., (2014): Some amendments to calcareous nannoplankton taxonomy. - Journal of Nannoplankton Research. 33(1): 39-46.

Taxonomy

Velonalithus

Biostratigraphy

Stratigraphic Range

Langhian - Serravalian

Age (Ma)

15.99? - 12.32

Holotype

Triquetrorhabdulus rioensis Olafsson, 1989

Middle Miocene

ODP Leg 108, Site 667A, Eastern Tropical Atlantic