前寒武纪-寒武纪交界时期发生的从软体动物到介壳动物的变化,是地质记录中最引人注目、最重要而又了解最少的事件之一。关于这一事件(通常被称为寒武纪生物激增或寒武纪辐射(radiation)事件)的起因,一直是众多推测的对象。可能的解释包括:大气氧含量达到临界水平或大气中二氧化碳浓度降低;由于世界范围的海侵形成了新的浅海生态环境;由 The change from molluscs to crustaceans occurring during the Precambrian-Cambrian boundary period is one of the most striking, most important and least understood events in geological records. The causes of this event, often referred to as the Cambrian biological surge or the Cambrian radiation event, have been the subject of many speculations. Possible explanations include: the atmospheric oxygen content reaches a critical level or the concentration of carbon dioxide in the atmosphere decreases; a new shallow marine environment is formed due to worldwide transgression;