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Cambrian explosion condensed: High-precision geochronology of the lower Wood Canyon Formation, Nevada.

ABSTRACT: The geologically rapid appearance of fossils of modern animal phyla within Cambrian strata is a defining characteristic of the history of life on Earth. However, temporal calibration of the base of the Cambrian Period remains uncertain within millions of years, which has resulted in mounting challenges to the concept of a discrete Cambrian explosion. We present precise zircon U-Pb dates for the lower Wood Canyon Formation, Nevada. These data demonstrate the base of the Cambrian Period, as defined by both ichnofossil biostratigraphy and carbon isotope chemostratigraphy, was younger than 533 Mya, at least 6 My later than currently recognized. This new geochronology condenses previous age models for the Nemakit-Daldynian (early Cambrian) and, integrated with global records, demonstrates an explosive tempo to the early radiation of modern animal phyla.

SUBMITTER: Nelson LL

PROVIDER: S-EPMC10372641 | biostudies-literature | 2023 Jul

REPOSITORIES: biostudies-literature

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Cambrian explosion condensed: High-precision geochronology of the lower Wood Canyon Formation, Nevada.

Nelson Lyle L LL Crowley James L JL Smith Emily F EF Schwartz Darin M DM Hodgin Eben B EB Schmitz Mark D MD

Proceedings of the National Academy of Sciences of the United States of America 20230717 30

The geologically rapid appearance of fossils of modern animal phyla within Cambrian strata is a defining characteristic of the history of life on Earth. However, temporal calibration of the base of the Cambrian Period remains uncertain within millions of years, which has resulted in mounting challenges to the concept of a discrete Cambrian explosion. We present precise zircon U-Pb dates for the lower Wood Canyon Formation, Nevada. These data demonstrate the base of the Cambrian Period, as define ...[more]

PMID: 37459545

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