Ectasian
The Ectasian (from Greek "ectasis", "extension") is the second
geologic period in theMesoproterozoic era and lasted from 1400 Ma ago to 1200 Ma (million years ago). Instead of being based onstratigraphy , these dates are defined chronometrically.Name derives from continued expansion of
platform cover s during this period.Evidence of a eukaryotic
red alga e, "Bangiomorpha pubescens ", has been identified from ca. 1200 Ma old rocks in theHunting Formation (Somerset Island ,Canada ). This is the oldest knownsex ually reproducingorganism and therefore the earliest known complexmulticellular organism . [http://paleobiol.geoscienceworld.org/cgi/content/abstract/26/3/386]References
*cite web | title=Ectasian Period | work=GeoWhen Database | url=http://www.stratigraphy.org/geowhen/stages/Ectasian.html | accessmonthday=January 5 | accessyear=2006
*cite journal | author=James G. Ogg | title=Status on Divisions of the International Geologic Time Scale. | journal=Lethaia | year=2004 | volume=37 | issue= | pages=183–199 | url=http://www.stratigraphy.org/precambrian/Ogg_2003.pdf | doi=10.1080/00241160410006492
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Ectasian — 1. adjective of a geologic period within the Mesoproterozoic era from about 1400 to 1200 million years ago 2. noun the Ectasian period … Wiktionary
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