Department of Earth Sciences, University of Southern California, Los Angeles, CA, USA.
Geobiology. 2012 Jan;10(1):3-24. doi: 10.1111/j.1472-4669.2011.00305.x. Epub 2011 Nov 4.
Widespread development of microbialites characterizes the substrate and ecological response during the aftermath of two of the 'big five' mass extinctions of the Phanerozoic. This study reviews the microbial response recorded by macroscopic microbial structures to these events to examine how extinction mechanism may be linked to the style of microbialite development. Two main styles of response are recognized: (i) the expansion of microbialites into environments not previously occupied during the pre-extinction interval and (ii) increases in microbialite abundance and attainment of ecological dominance within environments occupied prior to the extinction. The Late Devonian biotic crisis contributed toward the decimation of platform margin reef taxa and was followed by increases in microbialite abundance in Famennian and earliest Carboniferous platform interior, margin, and slope settings. The end-Permian event records the suppression of infaunal activity and an elimination of metazoan-dominated reefs. The aftermath of this mass extinction is characterized by the expansion of microbialites into new environments including offshore and nearshore ramp, platform interior, and slope settings. The mass extinctions at the end of the Triassic and Cretaceous have not yet been associated with a macroscopic microbial response, although one has been suggested for the end-Ordovician event. The case for microbialites behaving as 'disaster forms' in the aftermath of mass extinctions accurately describes the response following the Late Devonian and end-Permian events, and this may be because each is marked by the reduction of reef communities in addition to a suppression of bioturbation related to the development of shallow-water anoxia.
微生物岩的广泛发育是显生宙五次大灭绝事件后基质和生态响应的特征。本研究通过宏观微生物结构记录的微生物响应来检验灭绝机制与微生物岩发育方式之间的联系，对这两个事件的微生物响应进行了综述。识别出两种主要的响应方式：（i）微生物岩扩展到灭绝前间隔期间未占据的环境中，以及（ii）微生物岩丰度增加并在灭绝前占据的环境中获得生态优势。晚泥盆世生物危机导致了台地边缘礁生物灭绝，随后在法门阶和早石炭世台地内部、边缘和斜坡环境中微生物岩丰度增加。二叠纪末灭绝事件记录了底栖动物活动的抑制和以后生动物为主的礁的消除。这次大灭绝的后果是微生物岩扩展到新的环境中，包括近海和近岸缓坡、台地内部和斜坡环境。三叠纪末和白垩纪末的大灭绝尚未与宏观微生物响应相关联，尽管有人认为奥陶纪末事件存在这种关联。微生物岩在大灭绝后的“灾难形式”行为的说法准确地描述了晚泥盆世和二叠纪末事件之后的响应，这可能是因为每次事件都以除了生物扰动抑制之外，还以礁群落的减少为标志，这与浅水缺氧的发展有关。
