Discoaster bollii

Martini & Bramlette, 1963 Apr 24, 2021

Set number: 807

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10µm

Discoaster bollii, Late Miocene, Gulf of Mexico

Set number: 808

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10µm

Discoaster bollii, Late Miocene, Gulf of Mexico

Set number: 810

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10µm

Discoaster bollii, Late Miocene, Gulf of Mexico

Set number: 811

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10µm

Discoaster bollii, Late Miocene, Gulf of Mexico

Set number: 812

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10µm

Discoaster bollii, Late Miocene, Gulf of Mexico

Set number: 809

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10µm

Discoaster bollii, Late Miocene, Gulf of Mexico

short arm variant

Set number: 810

1
2
3
4
5
6
7
8

10µm

Discoaster bollii, Late Miocene, Gulf of Mexico

Set number: 809

1
2
3
4

10µm

Discoaster bollii, Late Miocene, Gulf of Mexico

short arm variant

Set number: 812

1
2
3
4
5
6
7
8
9
10
11
12

10µm

Discoaster bollii, Late Miocene, Gulf of Mexico

Set number: 811

1
2
3
4
5
6
7
8
9
10

10µm

Discoaster bollii, Late Miocene, Gulf of Mexico

Set number: 808

1
2
3

10µm

Discoaster bollii, Late Miocene, Gulf of Mexico

Set number: 807

1
2
3
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.

Taxonomy

Discoaster

Biostratigraphy

Stratigraphic Range

Tortonian

Age (Ma)

10.71 - 9.21

Holotype

Discoaster bollii Martini & Bramlette, 1963

Late Miocene

Trinidad, about 1 mile south of Princes Town (type locality of Globorotalia menardii Zone, Lengua Formation).