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Revision of Discoasteraceae from Mon, 14/01/2008 - 19:22

Mon, 14/01/2008 - 19:38 — Jeremy Young
Citation: 
FAMILY DISCOASTERACEAE TAN, 1927

Description. Discoidal nannoliths of 3-40 elements radiating from a common centre. C-axes vertical, so nannoliths appear dark in plane-polarised light. Some early forms also include a cycle of birefringent units.

Taxa included: Discoaster, Catinaster.

variabilis.jpg

Discoaster variabilis group

6-rayed discoasters with bifurcations.

brouweri.jpg

Discoaster brouweri group

6-rayed discoasters without bifurcations, and forms closely related to D. brouweri with 3 to 5 rays

pentaradiatus.jpg

Discoaster pentaradiatus group

symmetric 5-rayed discoasters

 c._coalitus.jpg

Catinaster

6-rayed discosters in which the birfurcations meet to form a rim, which extends proximally   

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