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Three-Dimensional Preservation of Cellular and Subcellular Structures Suggests 1.6 Billion-Year-Old Crown-Group Red Algae
The last common ancestor of modern eukaryotes is generally believed to have lived during the Mesoproterozoic era, about 1.6 to 1 billion years ago, or possibly somewhat earlier. This study by Bengtson et al. reveals the presence of two types of proposed red alga embedded amid cyanobacterial mats from 1.6 billion-year-old sediments found in Chitrakoot, India. These fossils predate the previously earliest accepted red algae by about 400 million years, suggesting that eukaryotes may have a longer history than commonly assumed. The image shows a false-colored X-ray microtomographic picture of the thread-like fossil red alga Rafatazmia chitrakootensis. Each well-preserved cell contains a rhombic platelet (bright green) assumed to belong to the photosynthesising apparatus. The filament shown here is about 0.5 mm long.
Image Credit: Stefan Bengtson
Citation: (2017) PLoS Biology Issue Image | Vol. 15(3) March 2017. PLoS Biol 15(3): ev15.i03. https://doi.org/10.1371/image.pbio.v15.i03
Published: March 31, 2017
Copyright: © 2017 Bengtson. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
The last common ancestor of modern eukaryotes is generally believed to have lived during the Mesoproterozoic era, about 1.6 to 1 billion years ago, or possibly somewhat earlier. This study by Bengtson et al. reveals the presence of two types of proposed red alga embedded amid cyanobacterial mats from 1.6 billion-year-old sediments found in Chitrakoot, India. These fossils predate the previously earliest accepted red algae by about 400 million years, suggesting that eukaryotes may have a longer history than commonly assumed. The image shows a false-colored X-ray microtomographic picture of the thread-like fossil red alga Rafatazmia chitrakootensis. Each well-preserved cell contains a rhombic platelet (bright green) assumed to belong to the photosynthesising apparatus. The filament shown here is about 0.5 mm long.
Image Credit: Stefan Bengtson