Dataset from: Lung evolution in vertebrates and the water-to-land transition

A crucial evolutionary change in vertebrate history was the Palaeozoic (Devonian ~400 million years ago) water-to-land transition, allowed by key morphological and physiological modifications including the acquisition of lungs. Nonetheless, the origin and early evolution of vertebrate lungs remain highly controversial, particularly whether the ancestral state was paired or unpaired. Due to the rarity of fossil soft tissue preservation, lung evolution can only be traced based on the extant phylogenetic bracket. Here we investigate, for the first time, lung morphology in extensive developmental series of key living lunged osteichthyans using synchrotron X-ray microtomography and histology. Our results shed light on the primitive state of vertebrate lungs as unpaired, evolving to be truly paired in the lineage towards the tetrapods. The water-to-land transition confronted profound physiological challenges and paired lungs were decisive for increasing the surface area and the pulmonary comp...

脊椎动物演化史上的一个关键变革是古生代（泥盆纪，约4亿年前）的水陆过渡，这一转变由包括肺的获得在内的关键形态与生理改造所促成。然而，脊椎动物肺的起源与早期演化仍存在极大争议，尤其是其祖先状态为成对还是不成对这一问题。由于化石软组织保存极为罕见，肺的演化只能基于现存系统发育支架（extant phylogenetic bracket）进行追溯。本研究首次利用同步辐射X射线显微断层扫描（synchrotron X-ray microtomography）与组织学技术，对关键现生硬骨有肺鱼类的一系列广泛发育阶段的肺形态展开研究。我们的结果揭示了脊椎动物肺的原始状态为不成对，其在向四足动物演化的谱系中逐渐形成真正的成对结构。水陆过渡面临着深刻的生理挑战，而成对肺对于增加表面积及肺的压缩...