Niche partitioning shaped herbivore macroevolution through the early Mesozoic dataset

The Triassic (252–201 Ma) marks a major punctuation in Earth history, when ecosystems rebuilt themselves following the devastating Permian-Triassic mass extinction. Herbivory evolved independently several times as ecosystems comprising diverse assemblages of therapsids, parareptiles and archosauromorphs rose and fell, leading to a world dominated by dinosaurs. It was assumed that dinosaurs prevailed either through long-term competitive replacement of the incumbent clades or rapidly and opportunistically following one or more extinction events. Here we use functional morphology and ecology to explore herbivore morphospace through the Triassic and Early Jurassic. We identify five main herbivore guilds (ingestion generalists, prehension specialists, durophagous specialists, shearing pulpers, and heavy oral processors), and find that herbivore clades generally avoided competition by almost exclusively occupying different guilds. Major ecosystem remodelling was triggered multiple times by ex...

三叠纪（Triassic，2.52亿至2.01亿年前）是地球历史上的重要分界节点，彼时生态系统在毁灭性的二叠纪-三叠纪大灭绝事件（Permian-Triassic mass extinction）后完成重建。植食习性多次独立演化，由兽孔目（therapsids）、副爬行动物（parareptiles）与主龙形类（archosauromorphs）组成的多样类群群落兴衰更迭，最终造就了恐龙主导的世界。此前学界普遍认为，恐龙的称霸要么通过长期竞争性替代占据主导地位的原有类群，要么在一次或多次灭绝事件后快速抓住机遇实现崛起。本研究借助功能形态学（functional morphology）与生态学方法，探究了三叠纪至早侏罗世的植食动物形态空间（herbivore morphospace）。我们识别出五大主要植食动物功能群（guilds）：摄食泛化者（ingestion generalists）、取食特化者（prehension specialists）、硬食特化者（durophagous specialists）、剪切研磨者（shearing pulpers）与强口腔加工者（heavy oral processors），并发现植食类群几乎仅通过占据不同功能群来避免竞争。多次由外部因素触发了生态系统的重大重塑……