Collenia is genus of fossil cyanobacteria that form a particular type of stromatolites.
Description
Collenia are stromatolites made up of convex layers flattened in the center, forming columnar colonies. The microorganisms involved were likely photosynthetic bacteria expiring oxygen.Carroll Lane Fenton, Pat Vickers Rich, Mildred Adams Fenton, Thomas H. V. Rich The Fossil Book: A Record of Prehistoric Life
Fossil record Collenia stromatolites were very common in the Paleoproterozoic era during the Siderian and Rhyacian periods, about 2.2 to 2.4 billion years ago.
See also List of fossil stromatolites
References
External links Geological Survey Professional Paper, Volume 669 Spencer G. Lucas, Justin A. Spielmann, Patricia M. Hester, Jason P. Kenworthy, Vincent L. Santucci Americas Antiquities: 100 Years of Managing Fossils on Federal Lands Stromatolites - Precambrian: Archaean and Proterozoic Stromatolite Index of Generic Names of Fossil Plants, 1820-1950