The early Toarcian (Early Jurassic) and the Cenomanian-Turonian (Late Cretaceous) mass extinctions: similarities and contrasts
The early Toarcian (Early Jurassic) and the Cenomanian-Turonian (Late Cretaceous) mass extinctions: similarities and contrasts
复制标题
DOI：
10.1016/s0031-0182(99)00086-3
复制
发表时间：
1999-10-01
影响因子：
3
通讯作者：
Little, CTS
中科院分区：
文献类型：
--
作者：
Harries, PJ;Little, CTS
从不同的尺度和角度来看，早期的托尔西亚(ETO)和塞诺马尼亚-图罗尼亚(C-T)的大灭绝具有可比性。从广泛的角度来看，它们的相似之处包括：在家系和属的水平上几乎相同的灭绝强度，在海平面高位期间广泛沉积的盆地相，整体的温室气候，以及作为重要原因机制的缺氧。这里分析的高分辨率大型无脊椎动物数据，包括地层范围、多样性和丰度，指出了较小规模的相似之处。这两个事件导致了严重的生态破坏，在这两个案例中，生物反应非常相似。栖息在上层水柱中的分类群不受缺氧的影响，包括菊石，以及在ETO中的Belemnites。此外，在灭绝后的环境中，适应低氧条件的附生类群，如Buidhiidys、Posidoniids和Noveramids，在生存间隔期内蓬勃发展。随着条件的改善，生物群变得更加多样化，并逐渐开始类似于灭绝前的生物群。此外，三角洲(13)C曲线预测了生存间隔的结束，并表明以碳同位素漂移为特征的时期代表着破坏的环境条件。这表明，增量(13)C有可能作为一种工具，用于确定其他大规模物种灭绝的再种群模式和时间。(C)1999 Elsevier Science B.V.保留所有权利。
The early Toarcian (eTo) and Cenomanian-Turonian (C-T) mass extinctions are comparable from a wide range of scales and perspectives. From a broad standpoint, their similarities include: virtually identical extinction intensity at the familial and generic levels, widespread basinal facies deposited during sea-level highstands, an overall greenhouse climate, and anoxia as an important causal mechanism. The high-resolution, macroinvertebrate data analyzed here, consisting of stratigraphic ranges, diversity and abundance, point to smaller-scale similarities. The two events resulted in significant ecological disruption and, in both cases, the biotic responses were very similar. Taxa inhabiting the upper water column were unaffected by anoxia and included ammonites and, in the eTo, belemnites. In addition, epifaunal taxa adapted to low-oxygen conditions, such as the buchiids, posidoniids and inoceramids, flourished in the post-extinction environment during the survival interval. As conditions ameliorated, the biota became more diverse and gradually began to resemble pre-extinction biotas. Furthermore, the delta(13)C curves predict the end of the survival interval and suggest that the period characterized by carbon isotope excursions represent disrupted environmental conditions. This points to the potential application of delta(13)C as a tool for determining the repopulation modes and timing for other mass extinctions. (C) 1999 Elsevier Science B.V. All rights reserved.