{{Short description|Extinct genus of cyanobacteria}} {{Automatic taxobox | fossil_range = [[Siderian]]–[[Rhyacian]] {{Long fossil range|2400|2100}} | image = Collenia undosa Minnesota.jpg | image_caption = Section of ''Collenia undosa'' stromatolite from 2110 million year old [[banded iron formation]], [[Biwabik Township, St. Louis County, Minnesota|Biwabik]] | image2 = Stromatolithi - Collenia nudosa.JPG | image2_caption = ''Collenia undosa'' stromatolite from [[Precambrian]] of United States | taxon = Collenia | authority = [[Charles Doolittle Walcott|Walcott]] 1914<ref>[https://repository.si.edu/bitstream/handle/10088/23529/SMC_64_Walcott_1914_2_77-156.pdf Smithsonian miscellaneous collections Walcott 1914] si.edu</ref> | type_species = {{extinct}}'''''Collenia undosa''''' | subdivision_ranks = [[Species]] | subdivision = *{{extinct}}'''''C. frequens''''' *{{extinct}}'''''C. symmetrica''''' *{{extinct}}'''''C. undosa''''' }}
'''''Collenia''''' is [[genus]] of [[fossil]] [[cyanobacteria]] that form a particular type of [[stromatolite]]s.<ref name="Rich1996">{{cite book |author=Rich, Thomas H. V. |author2=Fenton, Carroll Lane |author2-link=Carroll Lane Fenton |author3=Fenton, Mildred Adams |author3-link=Mildred Adams Fenton |author4=Rich, Pat Vickers |title=The fossil book: a record of prehistoric life |publisher=Dover Publications |location=New York |year=1996 |isbn=0-486-29371-8 |url-access=registration |url=https://archive.org/details/fossilbookrecor00rich }}</ref>
==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.<ref>Carroll Lane Fenton,Pat Vickers Rich,Mildred Adams Fenton,Thomas H. V. Rich [https://books.google.com/books?id=_ntSspji0LYC&dq=Collenia+fossil&pg=PA87 The Fossil Book: A Record of Prehistoric Life]</ref>
==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== {{Reflist}}
==External links== * [https://books.google.com/books?id=uhOoAB52-gIC&dq=Collenia+fossil&pg=PA54 Geological Survey Professional Paper, Volume 669] * Spencer G. Lucas,Justin A. Spielmann,Patricia M. Hester,Jason P. Kenworthy,Vincent L. Santucci [https://books.google.com/books?id=q1bmCQAAQBAJ&dq=Collenia+fossil&pg=PA59 Americas Antiquities: 100 Years of Managing Fossils on Federal Lands] * [http://www.fossilmuseum.net/Fossil_Galleries/StromatolitesAmerica.htm Stromatolites - Precambrian: Archaean and Proterozoic Stromatolite] * [https://books.google.com/books?id=s6oPAAAAIAAJ&dq=Collenia+fossil&pg=PA133 Index of Generic Names of Fossil Plants, 1820-1950]
{{Taxonbar|from=Q5147044}}
[[Category:Proterozoic life]] [[Category:Cyanobacteria genera|†Collenia]] [[Category:Prehistoric bacteria]]