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Selectivity of end-Cretaceous marine bivalve extinctions
1Department of Geophysical Sciences, University of Chicago, IL 60637, USA.
Science (New York, N.Y.)
|April 21, 1995
Summary
Marine bivalves faced the end-Cretaceous mass extinction without bias for life position or size. Geographic distribution, not feeding mode, significantly impacted survival rates.
Area of Science:
- Paleontology
- Marine Biology
- Extinction Events
Background:
- The Cretaceous-Tertiary (K-T) extinction event profoundly impacted marine ecosystems.
- Understanding factors influencing genus survival during mass extinctions is crucial for evolutionary biology.
Purpose of the Study:
- To investigate selectivity patterns in marine bivalve genera during the end-Cretaceous mass extinction.
- To determine if life position, body size, or feeding mode influenced extinction intensity.
Main Methods:
- Analysis of marine bivalve genera extinction intensities.
- Comparison of extinction rates based on life position (burrowing vs. exposed).
- Assessment of extinction patterns related to body size, bathymetric distribution, and geographic range.
Main Results:
- No significant selectivity was observed for life position, body size, or bathymetric range.
- Deposit-feeders showed lower extinction than suspension-feeders, but this was driven by specific clades (Nuculoida, Lucinoidea).
- Geographically widespread genera exhibited significantly lower extinction intensities compared to narrowly distributed genera.
Conclusions:
- Survivorship during the K-T mass extinction was not determined by life position, body size, or feeding mode alone.
- Geographic distribution emerged as a key factor for genus survival during this major extinction event.
- Biotic factors promoting survival in non-catastrophic times may be ineffective during mass extinctions.
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