小柯机器人

美国弗吉尼亚理工大学Christopher T. Griffin等研究人员发现，非洲最古老的恐龙揭示恐龙分布的早期抑制。2022年8月31日，国际知名学术期刊《自然》在线发表了这一成果。

研究人员报告了来自津巴布韦的一个新的卡尼期集合体（其中包括非洲最古老确定的恐龙），包括一个几乎完整的长足动物Mbiresaurus raathi gen. et sp.nov.的骨架。这个集合体与其他含有恐龙的卡尼期集合体相似，表明一个类似的脊椎动物群在高纬度的澳洲盘古大陆上活动。第一批恐龙的分布与古纬度相关的气候障碍有关，恐龙向超大陆其他地区的扩散被推迟到这些障碍放松的时候，这表明气候控制影响了持续到今天的陆地动物群的最初组成。

据介绍，塑造中生代和新生代陆地生态系统的脊椎动物谱系起源于三叠纪盘古大陆。到了三叠纪晚期（卡尼期阶段，约2.35亿年前），世界性的"灾难动物群"已经让位于超级大陆上的高度地方性集合体。检验这种地方性的建立的速度和方式是具有挑战性的，在晚三叠世期间，在整个盘古大陆上几乎没有分散的地理障碍。相反，古地理气候带，而不是大陆边界，被认为控制了分布。在这个高地方性的时期，恐龙开始散布，因此提供了一个机会来检验这种生物地理模式的时间和驱动因素。增加取样可以检验这一预测：如果恐龙最初是在古地理学驱动的地方性扩散，那么与南美和印度的恐龙相似的组合（包括最早的恐龙）应该出现在非洲中南部的卡尼期的沉积中。

附：英文原文

Title: Africa’s oldest dinosaurs reveal early suppression of dinosaur distribution

Author: Griffin, Christopher T., Wynd, Brenen M., Munyikwa, Darlington, Broderick, Tim J., Zondo, Michel, Tolan, Stephen, Langer, Max C., Nesbitt, Sterling J., Taruvinga, Hazel R.

Issue&Volume: 2022-08-31

Abstract: The vertebrate lineages that would shape Mesozoic and Cenozoic terrestrial ecosystems originated across Triassic Pangaea1,2,3,4,5,6,7,8,9,10,11. By the Late Triassic (Carnian stage, ~235 million years ago), cosmopolitan ‘disaster faunas’ (refs. 12,13,14) had given way to highly endemic assemblages12,13 on the supercontinent. Testing the tempo and mode of the establishment of this endemism is challenging—there were few geographic barriers to dispersal across Pangaea during the Late Triassic. Instead, palaeolatitudinal climate belts, and not continental boundaries, are proposed to have controlled distribution15,16,17,18. During this time of high endemism, dinosaurs began to disperse and thus offer an opportunity to test the timing and drivers of this biogeographic pattern. Increased sampling can test this prediction: if dinosaurs initially dispersed under palaeolatitudinal-driven endemism, then an assemblage similar to those of South America4,19,20,21 and India19,22—including the earliest dinosaurs—should be present in Carnian deposits in south-central Africa. Here we report a new Carnian assemblage from Zimbabwe that includes Africa’s oldest definitive dinosaurs, including a nearly complete skeleton of the sauropodomorph Mbiresaurus raathi gen. et sp. nov. This assemblage resembles other dinosaur-bearing Carnian assemblages, suggesting that a similar vertebrate fauna ranged high-latitude austral Pangaea. The distribution of the first dinosaurs is correlated with palaeolatitude-linked climatic barriers, and dinosaurian dispersal to the rest of the supercontinent was delayed until these barriers relaxed, suggesting that climatic controls influenced the initial composition of the terrestrial faunas that persist to this day.

DOI: 10.1038/s41586-022-05133-x

Source: https://www.nature.com/articles/s41586-022-05133-x

Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
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