Mesoproterozoic Archaeoellipsoidès: akinetes of heterocystous cyanobacteria
Article first published online: 9 OCT 2007
Volume 28, Issue 4, pages 285–298, December 1995
How to Cite
GOLUBIC, S., SERGEEV, V. N. and KNOLL, A. H. (1995), Mesoproterozoic Archaeoellipsoidès: akinetes of heterocystous cyanobacteria. Lethaia, 28: 285–298. doi: 10.1111/j.1502-3931.1995.tb01817.x
- Issue published online: 9 OCT 2007
- Article first published online: 9 OCT 2007
The genus Archaeoellipsoides Horodyski & Donaldson comprises large (up to 135 μ 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. Akinetes, atmospheric oxygen, cyanobacteria, heterocyst, microbial fossils, nitrogen fixation, peritidal, Proterozoic.