Set number: 807

  • Discoaster bollii 1554 1
  • Discoaster bollii 1555 2
  • Discoaster bollii 1556 3
  • Discoaster bollii 1557 4
    10µm
Discoaster bollii, Late Miocene, Gulf of Mexico

Set number: 808

  • Discoaster bollii 1559 1
  • Discoaster bollii 1560 2
  • Discoaster bollii 1558 3
    10µm
Discoaster bollii, Late Miocene, Gulf of Mexico

Set number: 810

  • Discoaster bollii 29324 1
  • Discoaster bollii 29327 2
  • Discoaster bollii 29328 3
  • Discoaster bollii 29332 4
  • Discoaster bollii 29325 5
  • Discoaster bollii 29326 6
  • Discoaster bollii 29329 7
  • Discoaster bollii 29330 8
    10µm
Discoaster bollii, Late Miocene, Gulf of Mexico

Set number: 811

  • Discoaster bollii 29369 1
  • Discoaster bollii 29365 2
  • Discoaster bollii 29359 3
  • Discoaster bollii 29361 4
  • Discoaster bollii 29367 5
  • Discoaster bollii 29366 6
  • Discoaster bollii 29362 7
  • Discoaster bollii 29360 8
  • Discoaster bollii 29364 9
  • Discoaster bollii 29363 10
    10µm
Discoaster bollii, Late Miocene, Gulf of Mexico

Set number: 812

  • Discoaster bollii 29483 1
  • Discoaster bollii 29484 2
  • Discoaster bollii 29473 3
  • Discoaster bollii 29477 4
  • Discoaster bollii 29482 5
  • Discoaster bollii 29481 6
  • Discoaster bollii 29476 7
  • Discoaster bollii 29480 8
  • Discoaster bollii 29474 9
  • Discoaster bollii 29475 10
  • Discoaster bollii 29478 11
  • Discoaster bollii 29479 12
    10µm
Discoaster bollii, Late Miocene, Gulf of Mexico

Set number: 809

  • Discoaster bollii brevibrachium 19411 1
  • Discoaster bollii brevibrachium 19410 2
  • Discoaster bollii brevibrachium 19412 3
  • Discoaster bollii brevibrachium 19409 4
    10µm
Discoaster bollii, Late Miocene, Gulf of Mexico

short arm variant

Set number: 810

  • Discoaster bollii 29324 1
  • Discoaster bollii 29327 2
  • Discoaster bollii 29328 3
  • Discoaster bollii 29332 4
  • Discoaster bollii 29325 5
  • Discoaster bollii 29326 6
  • Discoaster bollii 29329 7
  • Discoaster bollii 29330 8
    10µm
Discoaster bollii, Late Miocene, Gulf of Mexico

Set number: 809

  • Discoaster bollii brevibrachium 19411 1
  • Discoaster bollii brevibrachium 19410 2
  • Discoaster bollii brevibrachium 19412 3
  • Discoaster bollii brevibrachium 19409 4
    10µm
Discoaster bollii, Late Miocene, Gulf of Mexico

short arm variant

Set number: 812

  • Discoaster bollii 29483 1
  • Discoaster bollii 29484 2
  • Discoaster bollii 29473 3
  • Discoaster bollii 29477 4
  • Discoaster bollii 29482 5
  • Discoaster bollii 29481 6
  • Discoaster bollii 29476 7
  • Discoaster bollii 29480 8
  • Discoaster bollii 29474 9
  • Discoaster bollii 29475 10
  • Discoaster bollii 29478 11
  • Discoaster bollii 29479 12
    10µm
Discoaster bollii, Late Miocene, Gulf of Mexico

Set number: 811

  • Discoaster bollii 29369 1
  • Discoaster bollii 29365 2
  • Discoaster bollii 29359 3
  • Discoaster bollii 29361 4
  • Discoaster bollii 29367 5
  • Discoaster bollii 29366 6
  • Discoaster bollii 29362 7
  • Discoaster bollii 29360 8
  • Discoaster bollii 29364 9
  • Discoaster bollii 29363 10
    10µm
Discoaster bollii, Late Miocene, Gulf of Mexico

Set number: 808

  • Discoaster bollii 1559 1
  • Discoaster bollii 1560 2
  • Discoaster bollii 1558 3
    10µm
Discoaster bollii, Late Miocene, Gulf of Mexico

Set number: 807

  • Discoaster bollii 1554 1
  • Discoaster bollii 1555 2
  • Discoaster bollii 1556 3
  • Discoaster bollii 1557 4
    10µm
Discoaster bollii, Late Miocene, Gulf of Mexico
Final Epithet
Discoaster bollii Martini & Bramlette, 1963
Basionym

Discoaster bollii Martini & Bramlette, 1963

Description

Large [>10.0µm] stellate species of Discoaster Tan Sin Hok (1927) having six tapering segments with bifurcations. The free length of the segments varies but often equal to or less than the diameter of the central area. Having sutural ridges with the prominent stellate distal process and proximal ridges with the low proximal process.

Discoaster bollii is another prominent member of the Late Miocene discoasters and shows considerable variation in the strengths of the distal process and proximal ridges. Its ranges vary considerably in the literature due to the adaptation of different species concept. We need a more rigid definition of Discoaster bollii and its variants to explore their full biostratigraphic potential.

Remarks

Discoaster bollii is distinguished from Discoaster exilis by having a prominent distal process and low proximal process.

Discoaster bollii differs from any other Late Miocene Discoaster by having processes on both sides.

References

Martini, E. & Bramlette, M. N., (1963): Calcareous nannoplankton from the experimental Mohole drilling. - Journal of Paleontology. 37(4): 845-855.

Tan Sin Hok, (1927): Discoasteridae incertae sedis. - Proceedings of the Koninklijke Nederlandse Akademie van Wetenschappen. Sect Sci, 30: 411-419.