Refined ages of marine fossils clarify the timing of diversification and extinction events Discussions about the quality of the fossil record frequently focus on completeness—that is, the proportion of species that existed for which scientists have fossil samples. An equally important aspect of quality is how finely the ages of fossils and durations of major evolutionary events can be resolved. Paleontologists and other biologists typically date fossils using the general ages of the chronostratigraphic units assigned to the rock strata yielding the fossils. For example, if a fossiliferous bed comes from the Rhuddanian Gasworks Sandstone, then the ages assigned to the fossils are usually 443.8 to 440.8 million years. On page 272 of this issue, Fan et al. (1) report on their use of constrained optimization (CONOP) (2) in biochronological analyses of fossil-bearing layers containing 11,000+ marine invertebrate species from 3000+ sections of sedimentary rocks, which constrain ages to a fraction of that range.

中文翻译：

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古生代化石的高分辨率年代测定

海洋化石的精确年龄澄清了多样化和灭绝事件的时间 关于化石记录质量的讨论经常关注完整性——即科学家拥有化石样本的存在物种的比例。质量的一个同样重要的方面是化石的年龄和主要进化事件的持续时间可以得到多么精细的解决。古生物学家和其他生物学家通常使用分配给产生化石的岩层的年代地层单位的一般年龄来确定化石的年代。例如，如果含化石的床来自 Ruddanian Gasworks 砂岩，则分配给化石的年龄通常为 443.8 至 440.8 百万年。在本期第 272 页，Fan 等人。