文章基本信息

标题：New Age of Fishes initiated by the Cretaceous−Paleogene mass extinction
本地全文：下载
作者：Elizabeth C. Sibert ; Richard D. Norris
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2015
卷号：112
期号：28
页码：8537-8542
DOI：10.1073/pnas.1504985112
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceRay-finned fishes are the most diverse and ecologically dominant group of vertebrates on the planet. Previous molecular phylogenies and paleontological studies have shown that modern ray-finned fishes (crown teleosts) radiated sometime in the Late Cretaceous or early Paleogene. Our data suggest that crown teleosts came into their current dominant ecological role in pelagic ecosystems immediately following the Cretaceous-Paleogene mass extinction 66 million years ago by filling newly vacated ecological niches and marking the beginning of an "age of ray-finned fishes." Our study is, to our knowledge, the first geographically comprehensive, high-resolution study of marine vertebrate communities across the extinction. Ray-finned fishes (Actinopterygii) comprise nearly half of all modern vertebrate diversity, and are an ecologically and numerically dominant megafauna in most aquatic environments. Crown teleost fishes diversified relatively recently, during the Late Cretaceous and early Paleogene, although the exact timing and cause of their radiation and rise to ecological dominance is poorly constrained. Here we use microfossil teeth and shark dermal scales (ichthyoliths) preserved in deep-sea sediments to study the changes in the pelagic fish community in the latest Cretaceous and early Paleogene. We find that the Cretaceous-Paleogene (K/Pg) extinction event marked a profound change in the structure of ichthyolith communities around the globe: Whereas shark denticles outnumber ray-finned fish teeth in Cretaceous deep-sea sediments around the world, there is a dramatic increase in the proportion of ray-finned fish teeth to shark denticles in the Paleocene. There is also an increase in size and numerical abundance of ray-finned fish teeth at the boundary. These changes are sustained through at least the first 24 million years of the Cenozoic. This new fish community structure began at the K/Pg mass extinction, suggesting the extinction event played an important role in initiating the modern "age of fishes."
关键词：Cretaceous−Paleogene boundary ; ichthyoliths ; fossil fish ; age of fishes ; mass extinction