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Molecules and the Early Fossil Record

Published online by Cambridge University Press:  08 April 2016

James W. Valentine
James W. Valentine*
Affiliation:
Department of Geological Sciences, University of California, Santa Barbara, California 93106
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Extract

The earliest fossil record of animals has long been an enigma. For nearly a century after the appearance of The Origin of Species, mineralized trilobites were thought to be among the first organisms to appear as fossils, and as they were considered to be complex life forms, a long previous episode of animal evolution seemed to be indicated. Discovery and description of Tommotian and Vendian faunas, with their small shelly and Ediacaran fossils respectively, provided us with an idea of the nature of organisms in strata that are progressively older than the trilobite-bearing beds. Yet in these older assemblages we do not find the sorts of organisms that might be expected to be precursors to the well-known Phanerozoic clades. The puzzle remains.

Type
Current Research
Information
Paleobiology , Volume 16 , Issue 1 , Winter 1990 , pp. 94 - 95
Copyright
Copyright © The Paleontological Society 

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References

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