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Mesoproterozoic Archaeoellipsoides: akinetes of heterocystous cyanobacteriaThe genus Archaeoellipsoides Horodyski & Donaldson comprises large (up to 135 micrometers long) ellipsoidal and rod-shaped microfossils commonly found in silicified peritidal carbonates of Mesoproterozoic age. Based on morphometric and sedimentary comparisons with the akinetes of modern bloom-forming Anabaena species, Archaeoellipsoides is interpreted as the fossilized remains of akinetes produced by planktic heterocystous cyanobacteria. These fossils set a minimum date for the evolution of derived cyanobacteria capable of marked cell differentiation, and they corroborate geochemical evidence indicating that atmospheric oxygen levels were well above 1% of present day levels 1,500 million years ago.
Document ID
20040089680
Acquisition Source
Headquarters
Document Type
Reprint (Version printed in journal)
Authors
Golubic, S.
(Boston University MA 02215, United States)
Sergeev, V. N.
Knoll, A. H.
Date Acquired
August 21, 2013
Publication Date
January 1, 1995
Publication Information
Publication: Lethaia
Volume: 28
ISSN: 0024-1164
Subject Category
Exobiology
Funding Number(s)
CONTRACT_GRANT: NAGW-893
CONTRACT_GRANT: 9305-9403
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Exobiology
Non-NASA Center

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