How to translate text using browser tools
2 July 2024 DEAD CLADE WALKING: THE PERSISTENCE OF ARCHAEOCYATHUS IN THE AFTERMATH OF EARLY CAMBRIAN REEF EXTINCTION IN THE WESTERN UNITED STATES
Sara B. Pruss, Grace Karbowski, Andrey Yu Zhuravlev, Mark Webster, Emily F. Smith
Author Affiliations +
Abstract

Archaeocyaths, the first metazoan reef builders of the Phanerozoic, faced their ultimate demise during early Cambrian Age 4 but the exact timing of their local extinctions varied globally. In this study, we report archaeocyaths in strata that overlie the last robust archaeocyathan reefs of the western United States (Laurentian Cordillera). These are found in small microbial mounds in the upper unit of the Mule Spring Limestone near Split Mountain, Clayton Ridge, Nevada, as well as in storm beds in the Thimble Limestone Member of the Carrara Formation in Echo Canyon of the Funeral Mountains, Death Valley, California. Thin-section analysis revealed the presence of modular archaeocyaths, with Archaeocyathus being the only genus present. The small microbial mounds of the lowermost upper unit of the Mule Spring Limestone preserve frame-building Archaeocyathus in situ, a few meters above the well-known Bristolia beds of the Mule Spring Limestone. As some of the youngest known archaeocyaths of the western US, these occurrences represent the last gasp of archaeocyaths in the early Cambrian of Laurentia and one of the latest occurrences globally of archaeocyaths. We thus interpret Archaeocyathus in these units as an example of a dead clade walking—some of the last true archaeocyaths that locally persisted into the later Age 4 Cambrian following the disappearance of diverse archaeocyath reefs in western Laurentia. These last archaeocyath communities exhibited low diversity and disparity before the total extirpation of this reef-building hypercalcified sponge and their ecosystem.

Sara B. Pruss, Grace Karbowski, Andrey Yu Zhuravlev, Mark Webster, and Emily F. Smith "DEAD CLADE WALKING: THE PERSISTENCE OF ARCHAEOCYATHUS IN THE AFTERMATH OF EARLY CAMBRIAN REEF EXTINCTION IN THE WESTERN UNITED STATES," PALAIOS 39(6), 210-224, (2 July 2024). https://doi.org/10.2110/palo.2024.005
Received: 14 February 2024; Accepted: 10 May 2024; Published: 2 July 2024
JOURNAL ARTICLE
15 PAGES

This article is only available to subscribers.
It is not available for individual sale.
+ SAVE TO MY LIBRARY

RIGHTS & PERMISSIONS
Get copyright permission
Back to Top