Set number: 928

  • Sphenolithus multispinatus 28210 1
  • Sphenolithus multispinatus 28206 2
  • Sphenolithus multispinatus 28213 3
  • Sphenolithus multispinatus 28208 4
  • Sphenolithus multispinatus 28212 5
  • Sphenolithus multispinatus 28207 6
    10µm
Sphenolithus multispinatus, Late Oligocene, DSDP Leg 25, Site 242, Mozambique Channel (Davie Ridge), Indian Ocean

Set number: 927

  • Sphenolithus multispinatus 27994 1
  • Sphenolithus multispinatus 27990 2
  • Sphenolithus multispinatus 27993 3
  • Sphenolithus multispinatus 28000 4
  • Sphenolithus multispinatus 27995 5
  • Sphenolithus multispinatus 27991 6
  • Sphenolithus multispinatus 27992 7
  • Sphenolithus multispinatus 27998 8
    10µm
Sphenolithus multispinatus, Late Oligocene, DSDP Leg 25, Site 242, Mozambique Channel (Davie Ridge), Indian Ocean

Set number: 926

  • Sphenolithus multispinatus 281 1
  • Sphenolithus multispinatus 280 2
  • Sphenolithus multispinatus 278 3
  • Sphenolithus multispinatus 279 4
    10µm
Sphenolithus multispinatus, Early Miocene, DSDP Leg 25, Site 242, Mozambique Channel (Davie Ridge), Indian Ocean
Final Epithet
Sphenolithus multispinatus Maiorano & Monechi, 1997
Basionym

Sphenolithus multispinatus Maiorano & Monechi, 1997

Description

Medium to large size (5.0-9.0µm) species of Sphenolithus Deflandre in Grassé,1952 having a frustum shape proximal cycle in the various height, reduced lateral cycle and gently diverging long apical spines made up of three or more long segments. In the side view, all the segments of the apical spine with axial c-axises show maximum birefringence at 45°, whereas only two outer segments show maximum birefringence at 0°. The lateral cycle is more distinct at 45°, where the proximal cycle is extinct (dim).
Two variants of the proximal cycle were noted; short wide, and relatively high elongated.

Remarks

Sphenolithus multispinatus differs from Sphenolithus cometa de Kaenel & Villa, 1996 by having apical spines with greater outward divergence and frustum shape lateral cycle.

References

de Kaenel, E., Villa, G., 1996. Oligocene-Miocene calcareous nannofossil biostratigraphy and paleoeecology from the Iberian Abyssal Plain. Proceedings of the Ocean Drilling Program, Scientific Results 149, 79-145.

Maiorano, P., Monechi, S., 1997. New Early Miocene species of Sphenolithus Deflandre, 1952 from the North Atlantic Ocean. Journal of Nannoplankton Research 19(2), 103-107.