Set number: 1276

  • Helicosphaera neointermedia VR 05541 1
  • Helicosphaera neointermedia VR 05536 2
  • Helicosphaera neointermedia VR 05540 3
  • Helicosphaera neointermedia VR 05552 4
  • Helicosphaera neointermedia VR 05542 5
  • Helicosphaera neointermedia VR 05538 6
  • Helicosphaera neointermedia VR 05539 7
  • Helicosphaera neointermedia VR 05551 8
  • Helicosphaera neointermedia VR 05543 9
  • Helicosphaera neointermedia VR 05547 10
  • Helicosphaera neointermedia VR 05549 11
  • Helicosphaera neointermedia VR 05550 12
    10µm
Helicosphaera kilida, Middle Pleistocene, DSDP Leg 23 Site 229A, Red Sea

Set number: 1275

  • Helicosphaera neointermedia VR 05327 1
  • Helicosphaera neointermedia VR 05326 2
  • Helicosphaera neointermedia VR 05330 3
  • Helicosphaera neointermedia VR 05336 4
  • Helicosphaera neointermedia VR 05328 5
  • Helicosphaera neointermedia VR 05325 6
  • Helicosphaera neointermedia VR 05329 7
  • Helicosphaera neointermedia VR 05338 8
  • Helicosphaera neointermedia VR 05333 9
  • Helicosphaera neointermedia VR 05332 10
  • Helicosphaera neointermedia VR 05334 11
  • Helicosphaera neointermedia VR 05335 12
    10µm
Helicosphaera kilida, Middle Pleistocene, DSDP Leg 23 Site 229A, Red Sea
Final Epithet
Helicosphaera kilida Varol, 2025
Basionym

Helicosphaera kilida Varol, 2025

Diagnosis

A helicolith characterised by a Type III (Helicosphaera carteri type) blanket, an expanded flange termination, and a central area occupied by a multi-segmented disjunct inverse plate/bar that fills the central opening entirely.

Etymology

Derived from the Greek kilida, meaning “patch,” referring to the disjunct central plate composed of several minute, irregular segments resembling patchwork.

Description

Optical Properties: Helicosphaera kilida exhibits inclined extinction angles of about 65° on the blanket on the distal side and shows length-fast (−) elongation.

Remarks

Helicosphaera kilida differs from Helicosphaera intermedia by the presence of this multi-segmented disjunct inverse plate/bar. In contrast, Helicosphaera intermedia features a well-defined oblique disjunct bar that often leaves an open space of varying width.

References

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