Evolutionary rates of mid-Permian tetrapods from South Africa and the role of temporal resolution in turnover reconstruction

The Main Karoo Basin of South Africa contains a near-continuous sequence of continental deposition spanning 45 million years from the middle Permian to the Early Jurassic. The terrestrial vertebrates of this sequence provide a high-resolution stratigraphic record of regional origination and extinction, especially for the middle–late Permian. Until now, data have only been surveyed at coarse stratigraphic resolution using methods that are biased by non-uniform sampling rates, limiting our understanding of the dynamics of diversification through this important time period. High-resolution data now cross the mid-to-late Permian transition; to these we apply robust methods (gap-filler and modified gap-filler rates) for the inference of patterns of species richness, origination rates and extinction rates to a subset of 1321 securely-identified fossil occurrences resolved to approximately 50 metre stratigraphic intervals. This dataset provides an approximate time resolution of 0.3-0.6 million...南非卡鲁主盆地（Main Karoo Basin）赋存一套近乎连续的陆相沉积序列，时限从中二叠世至早侏罗世，跨度达4500万年。该序列产出的陆生脊椎动物化石，为区域物种起源与灭绝事件提供了高分辨率的地层记录，尤其在中二叠世至晚二叠世时段表现突出。此前相关研究仅采用粗分辨率地层采样方案，且采样方法受非均匀采样率偏差的影响，极大限制了学界对这一重要地质时期内生物多样化动态过程的认知。当前，研究已获取跨越中二叠世-晚二叠世过渡界面的高分辨率数据；我们针对其中经可靠鉴定的1321个化石产出点子集，采用稳健的分析方法（间隙填充法（gap-filler）与修正间隙填充速率法），以约50米的地层间隔为分辨率约束，以此推断物种丰富度、起源速率与灭绝速率的变化模式。本数据集的时间分辨率约为0.3-0.6百万年……