School of Earth Sciences, University of Bristol, Bristol, UK.
Nat Commun. 2021 May 14;12(1):2796. doi: 10.1038/s41467-021-23169-x.
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 external environmental challenges, and previously dominant herbivores were marginalised by newly emerging forms. Dinosaur dominance was a mix of opportunity following disaster, combined with competitive advantage in their new world.
三叠纪（252-201Ma）标志着地球历史上的一个重大转折点，当时生态系统在毁灭性的二叠纪-三叠纪大灭绝之后进行了重建。随着包括兽孔目动物、似哺乳爬行动物和主龙形类动物在内的多样化组合的生态系统兴衰，食草动物独立进化了多次，导致了一个由恐龙主导的世界。人们认为，恐龙之所以占优势，要么是通过长期对现有类群的竞争取代，要么是在一次或多次灭绝事件后迅速而机会主义地占据主导地位。在这里，我们使用功能形态学和生态学来探索三叠纪和早侏罗世的食草动物形态空间。我们确定了五个主要的食草动物类群（摄取泛化者、取食专业化者、硬壳食者、剪切研磨者和重型口腔处理器），并发现食草动物类群通常通过几乎完全占据不同的类群来避免竞争。主要的生态系统重塑是由外部环境挑战多次引发的，以前占主导地位的食草动物被新出现的形式边缘化了。恐龙的主导地位是灾难后机会的结合，加上它们在新世界中的竞争优势。
