Cambrian explosion condensed: High-precision geochronology of the lower Wood Canyon Formation, Nevada.
Proc Natl Acad Sci U S A
; 120(30): e2301478120, 2023 07 25.
Article
em En
| MEDLINE
| ID: mdl-37459545
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.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Madeira
/
Evolução Biológica
Tipo de estudo:
Prognostic_studies
Limite:
Animals
País como assunto:
America do norte
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article