Nannotax3 - ntax_Farinacci

Original descriptions of taxa. For coccolithophores, and many calcispheres, these are pages from the Farinacci & Howe Catalog of Calcareous Nannofossils. In other cases (e.g. non-calcifying haptophytes) the data is directly compiled on this site. The "Catalogue of Calcareous Nannofossils" was originally compiled by Prof A. Farinacci 1969-1989, since 2000 it has been updated and extended by Richard Howe - see The Farinacci and Howe Catalog - an Introduction.
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Citation: Noelia kolona Varol 2023

Type sample (& lithostrat): DSDP Leg 25, Site 245-12-2, 22.5 cm

Type age (chronostrat): Selandian, Zone NP5.

Standardised type level: 092_MIDDLE PALEOCENE

Type locality: Mozambique Channel (Davie Ridge), Indian Ocean

Type repository: not stated, presumalby the author's collection

Diagnosis: A circular species of Noelia consisting of a non- birefringent distal shield, an appressed proximal shield and a broad distally protruding tube cycle with a serrated periphery.

Description: A large (8.0–11.0 μm) species of Noelia with a non- birefringent lenticular distal shield. The distal shield and the tube cycle are constructed of similar segments (about 24–36). The number of segments in the tube cycle is easily determined in a bright field setting and cross-polarised light with a gypsum plate (Plate 12, Figs. 20, 22).

The tube cycle and the appressed proximal shield appear as an asymmetrical X-shape in side view (Plate 11, Figs. 2,6). The diameter of the broad tube cycle is much greater than the width of the shield and always protrudes distally above the distal shield. There is a distinct depression at the distal end of the tube cycle.

In cross-polarised light, when using the gypsum plate, the blue regions correspond to the horizontal axis on the distal side (Plate 12, Fig. 22). In contrast, the blue sectors correspond to the vertical axis on the proximal side in the center of the coccolith (Plate 12, Fig. 24).

Dimensions of holotype: The diameter of the distal shield =8.98 μm (measured in plan view in phase-contrast), the diameter of the proximal shield =4.80 μm (measured in side view in cross-polarised light), the maximum diameter of the tube cycle =4.92 μm (measured in plan view in phase-contrast), the maximum thickness of the distal shield and tube cycle =4.17 μm (measured in cross-polarised light), the free length of the tube cycle =1.31 μm (measured in side view in cross- polarised light).

From the Greek kolona, column – refers to its high protruding tube cycle.

Remarks: Noelia kolona differs from Noelia mahaniae by being circular rather than subcircular with an elliptical central area. Noelia kolona is differentiated from Noelia uenverdii by the lack of a central opening, whilst the latter has a narrow central opening. Noelia kolona is recognised from Senelia, Carlamuelleria, Markalius and Davidbukrya by having a protruding tube cycle above the distal shield. The tube cycle in Senelia, Markalius and Davidbukrya does not protrude above the distal shield. Moreover, Noelia kolona is further distinguished from Davidbukrya, Carlamuelleria and Markalius by having an appressed proximal shield. In contrast, the proximal shield in Markalius is a spaced proximal shield with an acute inclination angle. Carlamuelleria and Davidbukrya have a vestigial, diminutive, or no proximal shield, respectively.

Occurrence: This species is recorded from DSDP Leg 25, Site 245A, Mozambique Channel (Davie Ridge), Indian Ocean; DSDP Leg 39, Site 354, Ceara Rise, Atlantic Ocean.

Stratigraphic range: Selandian-Thanetian (Zones NP5-NP7).

The type sample was listed as coming from hole 245A but was actually from hole 245

References:

Varol, O. (2023). New Paleocene calcareous nannofossils: Carlamuelleria, Davidbukrya, Mauriceblackia, Noelia and Senelia. Marine Micropaleontology. 180: 1-41. gs

CATALOG - Noelia kolona

References:

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