Large Spinose Microfossils in Ediacaran Rocks as Resting Stages of Early Animals

DSpace/Manakin Repository

Large Spinose Microfossils in Ediacaran Rocks as Resting Stages of Early Animals

Show simple item record

dc.contributor.author Kodner, Robin B.
dc.contributor.author Cohen, Phoebe A.
dc.contributor.author Knoll, Andrew
dc.date.accessioned 2009-05-21T19:28:48Z
dc.date.issued 2009
dc.identifier.citation Cohen, P. A., A. H. Knoll, and R. B. Kodner. 2009. Large spinose microfossils in Ediacaran rocks as resting stages of early animals. Proceedings of the National Academy of Sciences of the United States of America 106, no.16: 6519-6524. en
dc.identifier.issn 0027-8424 en
dc.identifier.uri http://nrs.harvard.edu/urn-3:HUL.InstRepos:2966792
dc.description.abstract Large (> 100 mu m), profusely ornamented microfossils comprise a distinctive paleontological component of sedimentary rocks deposited during the Ediacaran Period (635-542 million years ago). Smaller spinose fossils in Paleozoic rocks have commonly been interpreted as algal cysts or phycomata, but the Ediacaran populations differ from modern algal analogs in size, shape, ultrastructure, and internal contents. In contrast, cysts formed during the diapause egg-resting stages of many metazoans share features of size, ornamentation, and internal contents with large ornamented Ediacaran microfossils (LOEMs). Moreover, transmission electron microscopic observations of animal-resting cysts reveal a 3-layer wall ultrastructure comparable to that of LOEM taxa. Interpretation of these distinctive Ediacaran microfossils as resting stages in early metazoan life cycles offers additional perspectives on their functional morphology and stratigraphic distribution. Based on comparisons with modern marine invertebrates, the recalcitrant life stage represented by LOEMs is interpreted as an evolutionary response to prolonged episodes of bottom water anoxia in Ediacaran shelf and platform environments. As predicted by this hypothesis, the later Ediacaran disappearance of LOEM taxa coincides with geochemical evidence for a marked decline in the extent of oxygen-depleted waters impinging on continental shelves and platforms. Thus, the form, diversity, and stratigraphic range of LOEMs illuminate life cycle evolution in early animals as influenced by the evolving redox state of the oceans. en
dc.description.sponsorship Earth and Planetary Sciences en
dc.description.sponsorship Organismic and Evolutionary Biology en
dc.language.iso en_US en
dc.publisher National Academy of Sciences en
dc.relation.isversionof http://dx.doi.org/10.1073/pnas.0902322106 en
dash.license META_ONLY
dc.subject origin of metazoans en
dc.subject acritarchs en
dc.subject Diapause egg cysts en
dc.subject paleonenvironment en
dc.title Large Spinose Microfossils in Ediacaran Rocks as Resting Stages of Early Animals en
dc.relation.journal Proceedings of the National Academy of Sciences of the United States of America en
dash.depositing.author Knoll, Andrew
dash.embargo.until 10000-01-01

Files in this item

Files Size Format View xmlui.dri2xhtml.METS-1.0.item-files-description
Knoll_LargeSpinoseMicrofossils.pdf 823.0Kb PDF View/Open

This item appears in the following Collection(s)

  • FAS Scholarly Articles [7219]
    Peer reviewed scholarly articles from the Faculty of Arts and Sciences of Harvard University

Show simple item record

 
 

Search DASH


Advanced Search
 
 

Submitters