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Discoaster bergenii

Edited by Jeremy Young on Wed, 28/09/2011 - 22:42

Discoaster bergenii Knuttel, Russell and Firth, 1989

Description: Like D. quinqueramus but central-area very wide (>2x free ray length).

Remarks: D. bergenii, D. bergrennii and D. quinqueramus apparently form an anagenetic lineage, with central area size deceasing and free ray length increasing. Distinguishing them is useful for determining position within the early part of zone NN11.
See also separate page on this plexus.

 

Geological Time Data
Geological Time Periods: 
NN11a
NN11a
Biblio Reference: 
Young, JR.  1998.  Neogene. Calcareous nannofossil biostratigraphy. :225-265.

Comments

Wed, 28/09/2011 - 15:27 — mstyzen
mstyzen's picture

Discoaster quinqueramus/berggrenii plexus

I posted a document with some sketches from the original Gulf Coast Taxonomic Equivalency Project of this group in the forum.

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