Set number: 1274

  • Helicosphaera pteryga VR 05857 1
  • Helicosphaera pteryga VR 05861 2
  • Helicosphaera pteryga VR 05862 3
  • Helicosphaera pteryga VR 05871 4
  • Helicosphaera pteryga VR 05859 5
  • Helicosphaera pteryga VR 05863 6
  • Helicosphaera pteryga VR 05860 7
  • Helicosphaera pteryga VR 05870 8
  • Helicosphaera pteryga VR 05868 9
  • Helicosphaera pteryga VR 05865 10
  • Helicosphaera pteryga VR 05864 11
  • Helicosphaera pteryga VR 05869 12
    10µm
Helicosphaera pteryga, Middle Pleistocene, DSDP Leg 23 Site 229A, Red Sea
Final Epithet
Helicosphaera pteriga Varol, 2025
Basionym

Helicosphaera pteriga Varol, 2025

Diagnosis

A helicolith characterised by a Type III (Helicosphaera carteri type) blanket and a wing-like, expanded flange termination that extends nearly the entire length of the sinistral side of the helicolith. The proximal plate is featureless.

Etymology

Derived from the Greek pteryga, meaning “wing,” referring to the wing that extends nearly the entire length of the sinistral side of the helicolith

Description

Optical Properties: Helicosphaera pteryga exhibits inclined extinction angles of approximately 55° on the blanket on the distal side and displays length-fast (−) elongation

Remarks

Helicosphaera pteryga is distinguished from Helicosphaera burkei by its wing-like expanded flange termination, which extends almost the entire length of the sinistral side of the helicolith. In contrast, in Helicosphaera burkei, the wing is confined to the anterior end. Helicosphaera pteryga differs from Helicosphaeroides magnifica by its Type III blanket (Helicosphaera carteri type), in contrast to the Type I blanket (Helicosphaeroides ampliaperta type) found in the latter.

References

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