Terrestrial vertebrates from near the Triassic-Jurassic boundary in Portugal: excavation, geological context, and faunal change

在三叠纪/侏罗纪（TJ）边界附近发生的大规模灭绝（约100万年）。200 Ma）是地球历史上的“五大”大规模死亡之一。动物区系的变化涉及几乎所有现存的主要四足动物群（如哺乳动物、蜥蜴、海龟、鳄鱼和Lissampibians）以及恐龙和翼龙的起源。了解三叠纪末的大灭绝对于了解中生代脊椎动物的进化和现代脊椎动物群的起源至关重要。然而，我们的理解是目前有限的事实，很少有地质序列保存四足动物化石与TJ边界密切相关。为了更好地了解陆地上的三叠纪末事件，迫切需要发现和仔细记录跨越TJ边界的四足动物地质单元。我们建议在葡萄牙南部（阿尔加维）的重要TJ边界路段的第一次全面研究。这些部分是独特的保存脊椎动物骨床在几米的玄武岩熔岩流，标志着TJ边界。我们的目标是研究导致灭绝的脊椎动物区系变化，从而对这一事件的动态产生新的见解。

The mass extinction that occurred close to the Triassic/Jurassic (TJ) boundary (ca. 200 Ma) ranks among the “big five” mass die-offs in Earth history. Faunal change involved the origins of nearly all of the major living tetrapod groups (e.g. mammals, lizards, turtles, crocodilians, and lissamphibians), as well as dinosaurs and pterosaurs. An understanding of the end-Triassic mass extinction is crucial to understanding both Mesozoic vertebrate evolution and the origins of the modern vertebrate fauna. However, our understanding is currently limited by the fact that few geological sequences preserve tetrapod fossils in close association with the TJ boundary. In order to better understand the end-Triassic event on land, the discovery and careful documentation of tetrapod-bearing geological units that span the TJ boundary is urgently required. We propose the first comprehensive study of important TJ boundary sections in southern Portugal (Algarve). These sections are unique in preserving vertebrate bone-beds within a few metres of the basaltic lava flows that mark the TJ boundary. We aim to characterise vertebrate faunal change leading up the extinction, yielding new insights into the dynamics of this event.