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Resurrection of Dormant Daphnia magna: Protocol and Applications

Resurrection of Dormant Daphnia magna: Protocol and Applications

Published on: January 19, 2018

Evidence from ammonoids and conodonts for multiple Early Triassic mass extinctions.

Steven M Stanley¹

¹Department of Geology and Geophysics, University of Hawaii, Honolulu, HI 96822, USA. stevenst@hawaii.edu

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

|September 2, 2009

Summary

Early Triassic marine crises caused mass extinctions in ammonoids and conodonts. These resilient taxa, however, rapidly recovered, unlike less-studied marine groups.

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Area of Science:

Paleontology
Marine Biology
Geochemistry

Background:

Ammonoids and conodonts exhibit high origination/extinction rates, making them sensitive to environmental shifts.
Global environmental crises, particularly carbon isotopic excursions, intensify extinction rates.
Early Triassic negative carbon isotopic excursions mirrored Permian mass extinction events.

Observation:

Ammonoids and conodonts experienced significant mass extinctions during three Early Triassic negative carbon isotopic excursions.
These taxa demonstrated rapid rediversification between extinction events, consistent with their high origination rates.
Other marine taxa with lower origination rates were less impacted but remain poorly studied.

Findings:

High origination/extinction rate taxa like ammonoids and conodonts are vulnerable to global crises but recover quickly.
Early Triassic crises led to mass extinctions in ammonoids and conodonts, similar to Permian events.
Less-studied marine taxa with low origination rates showed modest diversity changes, obscured in the fossil record.

Implications:

The study highlights the differential impact of mass extinctions on marine taxa based on their intrinsic rates of origination and extinction.
Understanding ammonoid and conodont recovery provides insights into ecosystem resilience after environmental crises.
Further research on less-studied taxa is needed to fully comprehend the scope of Early Triassic marine life responses to global change.