Unusually Preserved Benthic Foraminiferal Assemblages from the Lower Triassic Virgin Limestone Member, Moenkopi Formation, Nevada, U.S.A

Authors

• Sara B. Pruss, Smith CollegeFollow
• Teagan E. McGuire, Smith College

Document Type

Article

Publication Date

7-24-2025

Publication Title

Journal of Foraminiferal Research

Abstract

The end-Permian mass extinction, the largest in Earth’s history, was so severe that biotic recovery was delayed for five or more million years. During the Early Triassic, ecosystems were populated by low diversity fauna, and the taphonomy of some fossil groups was reminiscent of Cambrian small shelly-style preservation. Herein we report a new assemblage of benthic foraminifera from the Lower Triassic (Olenekian, Spathian) Virgin Limestone Member, Moenkopi Formation in southern Nevada. Insoluble residues of carbonate samples produced >80 benthic foraminiferal tests, preserved as apatite- and iron oxide-internal molds. Dominant morphological groups include planispiral evolute forms, uniserial forms with round chambers, and uniserial forms with chevron U- and V-shaped chambers that are likely members of the classes Miliolata and Nodosariata. These benthic foraminifera preserved as internal molds have implications for recovery of unknown benthic organisms preserved in unusual ways in Lower Triassic rocks.

Volume

55

Issue

3

First Page

296

Last Page

311

Version

Version of Record

Comments

Open Access article.

Recommended Citation

Pruss, Sara B. and McGuire, Teagan E., "Unusually Preserved Benthic Foraminiferal Assemblages from the Lower Triassic Virgin Limestone Member, Moenkopi Formation, Nevada, U.S.A" (2025). Geosciences: Faculty Publications, Smith College, Northampton, MA.
https://scholarworks.smith.edu/geo_facpubs/230