Possible eukaryotic algal filaments from the late Proterozoic Chuar Group, Grand Canyon, Arizona

Carbonaceous filaments of possible eukaryotic algal affinity have been detected in ca. 850-m.y.-old mudstones near the top of the Awatubi Member of the Kwagunt Formation, Chuar Group, eastern Grand Canyon, Arizona. These filaments range from 40-130 mu m wide and are densely concentrated within a 0.1-mm-thick lamina.--Journal abstract.