美国丹佛自然与科学博物馆T. R. Lyson等研究人员发现了白垩纪到古近纪大灭绝后生物恢复的化石记录。这一研究成果于10月24日在线发表于《科学》。

研究人员报道了美国科罗拉多州的一个经过时间校准的地层剖面，其中包含哺乳动物、爬行动物和植物的异常完整的化石，并阐明了在白垩纪到古生物大灭绝（KPgE）后的鲜为人知的前一百万年中，生物恢复的动因和速度。

在KPgE发生后约10万年（ka），哺乳动物分类学丰富度翻了一番，最大哺乳动物体重增加到接近KPgE发生前的水平。在KPgE后约300 ka时，最大哺乳动物体重和饮食微环境分化水平增加了三倍，并伴随着直立花卉物种丰富度的增加。KPgE后约700 ka出现了其他大型哺乳动物，这与豆科（Leguminosae）的首次出现相吻合。

这些同时发生的植物和哺乳动物起源以及体重变化与变暖间隔相吻合，表明气候影响了KPgE后生物的恢复。

附：英文原文

Title: Exceptional continental record of biotic recovery after the Cretaceous–Paleogene mass extinction

Author: T. R. Lyson, I. M. Miller, A. D. Bercovici, K. Weissenburger, A. J. Fuentes, W. C. Clyde, J. W. Hagadorn, M. J. Butrim, K. R. Johnson, R. F. Fleming, R. S. Barclay, S. A. Maccracken, B. Lloyd, G. P. Wilson, D. W. Krause, S. G. B. Chester

Issue&Volume: 2019/10/24

Abstract: We report a time-calibrated stratigraphic section in Colorado that contains unusually complete fossils of mammals, reptiles, and plants, and elucidates the drivers and tempo of biotic recovery during the poorly known first million years after the Cretaceous–Paleogene mass extinction (KPgE). Within ~100 thousand years (ka) post-KPgE, mammalian taxonomic richness doubled and maximum mammalian body mass increased to near pre-KPgE levels. A three-fold increase in maximum mammalian body mass and dietary niche specialization occurred at ~300 ka post-KPgE, concomitant with increased megafloral standing species richness. The appearance of additional large mammals occurred by ~700 ka post-KPgE, coincident with the first appearance of Leguminosae (bean family). These concurrent plant and mammal originations and body mass shifts coincide with warming intervals, suggesting climate influenced post-KPgE biotic recovery.

DOI: 10.1126/science.aay2268

Source: https://science.sciencemag.org/content/early/2019/10/23/science.aay2268