Discoaster sanmiguelensis

Bukry, 1981b Jan 30, 2025

Set number: 3869

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10µm

Discoaster sanmiguelensis, Late Miocene, ODP Leg 154, Hole 926A, Ceará Rise, western equatorial Atlantic.

In the mobile mount.

Set number: 3870

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10µm

Discoaster sanmiguelensis, Middle Miocene, IODP Expedition 354, Hole U1451B, Bengal Fan, Indian Ocean

In the mobile mount

Set number: 3871

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10µm

Discoaster sanmiguelensis, Middle Miocene, IODP Expedition 354, Hole U1451B, Bengal Fan, Indian Ocean

Final Epithet

Discoaster sanmiguelensis Bukry, 1981b

Basionym

Discoaster sanmiguelensis Bukry, 1981b

Description

Emended description: Six-segmented species have a large central area decorated with prominent sutural ridges created by deep cavities on the distal side. In contrast, proximal ridges construct a platform created by ridges embellishing the bulging proximal side. The arms are much shorter than the diameter of the central area (about half) and have parallel-sided free lengths that terminate in notches. A careful focus is required to identify this species because a slight tilt can create a unique look; restricting the description in one orientation may create conflicting strati-graphic ranges.

Remarks

Discoaster sanmiguelensis differs from similar size Discoaster musicus by having a proximal platform created by ridges, whereas proximal ridges meet at the middle of the central area in Discoaster musicus. Discoaster sanmiguelensis is distinguished from Discoaster vandekampiorum by having segments with non-tapering arms.

References

Bukry, D (1981b. Pacific coast coccolith stratigraphy between Point Conception and Cabo Orientes.,Deep Sea Drilling Project Leg 63. Initial Reports of the Deep Sea Drilling Project. 63: 445-471.

Varol, O. & Bowman, A. R. 2024. The New Middle Miocene Genus Olladiscoaster, and Related and Associated Discoasters. Grzybowski Foundation Special Publication, 28: 1-103 pp.

Taxonomy

Discoaster

Biostratigraphy

Stratigraphic Range

Langhian - Tortonian

Zone(s)

NN5 - NN7

Age (Ma)

14.30 - 11.58

Holotype

Discoaster sanmiguelensis Bukry, 1981

Middle Miocene

DSDP Leg 63, Site 468, California Continental Borderland, USA