Denisea atalikii

Set number: 515

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10µm

Denisea atalikii, Late Paleocene, DSDP Leg 39, Sites 354, Ceará Rise, North Atlantic Ocean

Set number: 517

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10µm

Denisea atalikii, Middle Paleocene, DSDP Leg 39, Sites 354, Ceará Rise, North Atlantic Ocean

Set number: 518

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10µm

Denisea atalikii, Middle Paleocene, DSDP Leg 39, Sites 354, Ceará Rise, North Atlantic Ocean

Set number: 519

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10µm

Denisea atalikii, Late Paleocene, DSDP Leg 39, Sites 354, Ceará Rise, North Atlantic Ocean

Final Epithet

Denisea atalikii Varol, 2022

Basionym

Denisea atalikii Varol, 2022

Diagnosis

The medium-sized sub-circular species of Denisea have a large, empty, elliptical central area whose width is equal to or greater than the width of the pelaga.

Etymology

In honour of Dr Erkan Atalik, Geologist, Houston, Texas.

Dimensions Of Holotype

Length: 6.44 μm; width: 5.98 μm, the width of the pelaga: 1.92 μm; the length of the central area: 2.59 μm; the width of the central area: 2.09 μm; thickness: 2.07 μm.

Inclination angles of holotype: Distal shield: 55.7°; proximal shield: 57.9°; sutures between the shields: 55.2°; suture between the tube cycle and the shields: 47.2° (unexpectedly high, possibly due to the tilling).

Description

Medium-sized (5.0–9.0 μm) sub-circular species of Denisea constructed a birefringent tube cycle, two shields, and a wide, vacant, elliptical central area. The diameter of the central area is equal to or greater than the width of the pelaga.

Remarks

Denisea atalikii is smaller (< 9.0 μm) than the large sub-circular Denisea salleyi and an elliptical Denisea turkmenii. Denisea atalikii differs from the similarly sized Denisea subpertusa, Denisea foramena and Denisea aliquanta by being sub-circular and having an oval central area. The latter species are circular. Denisea subpertusa has a narrower central area than the width of the pelaga. It further differs from Denisea subpertusa in having a central area larger than the width of the pelaga.

References

Varol, O. 2022. Denisea, a new genus of Paleocene calcareous nannofossils. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 304/2 (2022): 159-186.