Kriogenium: Perbedaan antara revisi

'''Kriogenium''' (dari kata Bahasa Yunani: ''krýos'', "dingin", ''genesis'', "kelahiran") adalah [[periode (geologi)|periode geologi]] kedua pada [[era (geologi)|era]] [[Neoproterozoikum]] yang berlangsung dari 720 - 635 juta tahun yang lalu<ref name="SG-20170113">{{cite web|title=Chart|url=http://www.stratigraphy.org/index.php/ics-chart-timescale|publisher=International Commission on Stratigraphy|archive-url=https://web.archive.org/web/20170113013553/http://www.stratigraphy.org/index.php/ics-chart-timescale|archive-date=2017-01-13|access-date=2017-02-14|url-status=dead|df=dmy-all}}</ref>. Waktu tersebut bukan berdasarkan [[stratigrafi]], melainkan didefinisikan secara kronometrik. Kriogenium memiliki arti yaitu "[[zaman es]]", karena, pada saat ini, dua [[Periode glasial|glasiasi]] besar terjadi, yaitu [[Glasiasi Sturtian]] dan [[Glasiasi Marinoan]].<ref>{{Citation|title=How Volcanoes Froze the Earth (Twice)|url=https://www.youtube.com/watch?v=4ONwQV26L-k|accessdate=2021-09-16|language=id-ID}}</ref> Teori glasiasi ini menimbulkan perdebatan, apakah pada saat itu seluruh belahan Bumi tertutup Salju ([[Bumi Bola Salju]]) atau, masih ada "pita" lautan di [[khatulistiwa]].

Fosil dari [[Amoeba (genus)|amuba]] bercangkang ([[Arcellinida]]) pertamakali muncul pada periode ini<ref>{{cite journal|author1=Porter, S.A.|author2=Knoll, A.H.|year=2000|title=Testate amoeba in the Neoproterozoic Era: evidence from vase-shaped microfossils in the Chuar Group, Grand Canyon|url=http://nrs.harvard.edu/urn-3:HUL.InstRepos:3708936|journal=Paleobiology|volume=26|issue=3|pages=360–385|doi=10.1666/0094-8373(2000)026<0360:TAITNE>2.0.CO;2|issn=0094-8373|name-list-style=amp}}</ref>. Pada periode Kriogenium, hewan pertama muncul, yaitu [[Porifera]].<ref>{{cite journal|author=Love|last2=Grosjean|first2=Emmanuelle|last3=Stalvies|first3=Charlotte|last4=Fike|first4=David A.|last5=Grotzinger|first5=John P.|last6=Bradley|first6=Alexander S.|last7=Kelly|first7=Amy E.|last8=Bhatia|first8=Maya|last9=Meredith|first9=William|display-authors=etal|year=2009|title=Fossil steroids record the appearance of Demospongiae during the Cryogenian period|url=http://eaps.mit.edu/geobiology/recent%20pubs/Love%20et%20al%202009.pdf|journal=Nature|volume=457|issue=7230|pages=718–721|bibcode=2009Natur.457..718L|doi=10.1038/nature07673|pmid=19194449|s2cid=4314662|access-date=2022-01-27|archive-date=2018-05-08|archive-url=https://web.archive.org/web/20180508132248/http://eaps.mit.edu/geobiology/recent%20pubs/Love%20et%20al%202009.pdf|dead-url=yes}}</ref><ref>{{cite journal|last1=Maloof|first1=Adam C.|last2=Rose|first2=Catherine V.|last3=Beach|first3=Robert|last4=Samuels|first4=Bradley M.|last5=Calmet|first5=Claire C.|last6=Erwin|first6=Douglas H.|last7=Poirier|first7=Gerald R.|last8=Yao|first8=Nan|last9=Simons|first9=Frederik J.|date=17 August 2010|title=Possible animal-body fossils in pre-Marinoan limestones from South Australia|journal=Nature Geoscience|volume=3|issue=9|pages=653–659|bibcode=2010NatGe...3..653M|doi=10.1038/ngeo934}}</ref><ref>{{cite web|date=2010-08-17|title=Discovery of possible earliest animal life pushes back fossil record|url=http://www.physorg.com/news201273825.html}}</ref> Selain itu, masih ada perdebatan antara para ilmuwan, mengenai apakah glasiasi Sturtian/Marinoan mempengaruhi evolusi [[makhluk hidup]] atau tidak. Namun, Porter (2000), menyarankan bahwa beberapa cabang kehidupan muncul pada periode ini, yaitu [[alga merah]] dan [[Alga hijau|hijau]], [[Stramenopila|stramenofil]], [[ciliates]], [[dinoflagellata]], dan masih banyak lagi<ref>{{Cite web|title=Palaeos Proterozoic: Neoproterozoic: Cryogenian|url=http://palaeos.com/proterozoic/neoproterozoic/cryogenian/cryogenian2.html}}</ref>.