Perchnielsenella oweinaensis

(Perch-Nielsen, 1973c) Varol, 2025a Jun 16, 2025

Set number: 1974

  • Perchnielsenella oweinaensis VR 21292 1
  • Perchnielsenella oweinaensis VR 21280 2
  • Perchnielsenella oweinaensis VR 21296 3
  • Perchnielsenella oweinaensis VR 21276 4
  • Perchnielsenella oweinaensis VR 21282 5
  • Perchnielsenella oweinaensis VR 21279 6
  • Perchnielsenella oweinaensis VR 21278 7
  • Perchnielsenella oweinaensis VR 21275 8
  • Perchnielsenella oweinaensis VR 21290 9
  • Perchnielsenella oweinaensis VR 21289 10
  • Perchnielsenella oweinaensis VR 21288 11
  • Perchnielsenella oweinaensis VR 21287 12
  • Perchnielsenella oweinaensis VR 21283 13
  • Perchnielsenella oweinaensis VR 21284 14
  • Perchnielsenella oweinaensis VR 21285 15
  • Perchnielsenella oweinaensis VR 21286 16
    10µm
Aguablanca Creek, Colombia
Final Epithet
Perchnielsenella oweinaensis (Perch-Nielsen, 1973c) Varol, 2025a
Basionym

Cylindralithus oweinaensis Perch-Nielsen, 1973c

Remarks

A cylindrical calcareous nannofossil characterised by a double-storey, unicyclic wall that maintains a consistent width without widening or narrowing. Each storey comprises twelve to twenty-four strongly sinistrally imbricated segments and maintains a strictly circular shape in the plan view. The two walls are unequal in height, with their junction appearing indistinct under light microscopy (LM). A double-layered amedian diaphragm is present at the intersection. The outer surface of Perchnielsenella oweinaensis is densely ornamented with both lateral and longitudinal features. In both storeys of the wall, more prominent protruding nodes alternate with pits, forming a complete cycle near the junction surfaces.

Perchnielsenella oweinaensis differs from Perchnielsenella ismailkoselii by its dense lateral and longitudinal ornamentation on its outer surface. It is further distinguished from Perchnielsenella stradneri by its larger, strictly circular central opening in the plan view and a uniformly thick wall, excluding ornamentation in the side view. In contrast, Perchnielsenella stradneri has a circular to broadly elliptical, narrower central opening in the plan view and walls that gradually widen towards their intersection in the side view.

The optical properties of Perchnielsenella oweinaensis align with those observed in the family Perchnielsenaceae.

The correct citation is Perchnielsenella oweinaensis, not Perchnielsenella
oweinae, following ICN Art. 60D, as this species is named after the locality of Oweina in Egypt.

References

Varol, O. 2025a. A practical guide to optical studies of calcareous nannofossils. Grzybowski Foundation Special Publication. 29: 1-222

Perch-Nielsen, K. 1973c. Neue Coccolithen aus dem Maastrichtien von Danemark, Madagaskar und Agypten. Bulletin of the Geological Society of Denmark. 22: 306-333.

Taxonomy
Perchnielsenella
Biostratigraphy
  • Phanerozoic
    • Mesozoic
      • Cretaceous
        • Late Cretaceous
          • -
            • Maastrichtian
              • Early Maastrichtian
            • Campanian
              • Late Campanian
Stratigraphic Range
Late Campanian - Early Maastrichtian
Age (Ma)
76.38? - 69.91?
Zone(s)
CC23
Holotype
Perchnielsenella oweinaensis VR 21293

Cylindralithus oweinae Perch-Nielsen, 1973

Maastrichtian

Oweina, Egypt