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Geografía de las extinciones de bivalvos marinos del final del Cretácico
1Department of the Geophysical Sciences, University of Chicago, IL 60637.
Resumen
La extinción masiva de finales del Cretácico afectó a los bivalvos marinos a nivel mundial, sin que se detectaran patrones geográficos. Los aparentes picos de extinción tropical fueron causados por un grupo especializado de bivalvos, los rudistas.
Área de la Ciencia:
- Paleontología Paleontología.
- Biología Marina Biología Marina.
- Geología Geología Geología.
Sus antecedentes:
- El período final del Cretácico fue testigo de un evento significativo de extinción masiva.
- Los bivalvos marinos (Mollusca) son indicadores clave para la comprensión de los patrones de extinción.
Objetivo del estudio:
- Para analizar los patrones geográficos de la extinción masiva de finales del Cretácico en bivalvos marinos.
- Investigar el papel de taxones específicos, como los rudistas, en las intensidades de extinción observadas.
Principales métodos:
- Análisis de 3514 ocurrencias de 340 géneros de bivalvos marinos.
- Examen estadístico de las intensidades de extinción en diferentes latitudes y regiones geográficas.
Principales resultados:
- Las intensidades de extinción fueron uniformemente globales, sin gradientes latitudinales detectables.
- La aparente extinción elevada en las áreas tropicales se debió únicamente a la distribución de rudistas extintos.
- La exclusión de los rudistas reveló intensidades de extinción estadísticamente indistinguibles entre las regiones tropicales y extratropicales.
Conclusiones:
- El evento de extinción masiva de finales del Cretácico exhibió un patrón global en los bivalvos marinos.
- Los rudistas influyeron significativamente en las tasas de extinción regionales percibidas, enmascarando una intensidad de extinción global uniforme.
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