The evolution of insect flight as documented in the fossil record

翅膀的出现是昆虫进化过程中最引人注目的新奇事物之一，这种进化发生在数亿年前。最古老的有翼昆虫化石（翼龙目）大约有3.2亿年的历史。另外，大约4亿年前的化石碎片表明，在那个时候翼虫物种已经存在了。尽管如此，或者也许正是因为如此漫长的进化史，我们仍然不清楚昆虫的飞行装置是如何以及何时起源的。到目前为止，即使对现存的翼门动物进行了广泛的调查，也不能回答有关事件顺序的基本问题，特别是在昆虫飞行进化的早期。例如，翅膀起源于昆虫身体的哪个部位尚不清楚，翼门亚群之间的系统发育关系仍未得到解决。对于现存的翼目，如蜉蝣目、齿翅目和新翅目，包括它们的化石成员来说，这是正确的，但对于已经灭绝的古生代的古翅目、大翅目、透翅目和大翅目来说，更是如此。为了更好地理解昆虫飞行器官的进化过程以及昆虫的一般进化过程，我们将研究所有翼纲高等分类群的古生代化石，这些化石显示了翅膀脉络之外的飞行器官的重要部分，如通常复杂的翼关节和胸部。我们将研究来自几个石炭纪和二叠纪化石遗址的标本，例如，Hagen-Vorhalle（德国），Commentry（法国），Mazon Creek（美国），Sosnowiec（波兰），Tshekarda（俄罗斯），使用显微镜以及高分辨率x射线断层扫描，3d表面扫描（摄影）和扫描电子显微镜。对获得的数据进行比较分析，再加上关于现存翼鱼的资料，将能够重建翼鱼及其亚群的飞行装置的祖先状态。这将大大扩展我们对昆虫进化的认识和理解，昆虫是迄今为止所有生物中物种数量最多的群体。

The appearance of wings is one the most spectacular novelties in insect evolution that took place already hundreds millions of years ago. The oldest unequivocal fossils of winged insects (Pterygota) are ca. 320 million years old. Other, ca. 400 million year old, fragmentary fossils indicate that already at that time pterygote species existed. Despite of, or perhaps because of, this very long evolutionary history, it is still not clear how and when exactly the flight apparatus of insects originated. Even extensive investigations in the extant Pterygota could not, so far, answer basic questions on the sequence of events, especially during the early time of the evolution of insect flight. For example, it is not clear from which parts of the insect body the wings originated and the phylogenetic relationships among the subgroups of Pterygota are still largely unresolved. This is true for the extant pterygotes like Ephemeroptera, Odonata and Neoptera including their fossil members, but also and especially for the extinct Palaeozoic Palaeodictyoptera, Diaphanopterodea, Permothemistida and Megasecoptera.To gain a better understanding of the processes during the evolution of the flight apparatus of the insects as well as of the evolution of insects in general, we will study Palaeozoic fossils from all higher taxa of Pterygota that show important parts of the flight apparatus beyond the venation of the wings, like the often complex wing joint and the thorax. We will investigate specimens from several Carboniferous and Permian fossil sites like, e.g., Hagen-Vorhalle (Germany), Commentry (France), Mazon Creek (USA), Sosnowiec (Poland), Tshekarda (Russia) with microscopy as well as with high resolution X-ray tomography, 3D-surface scanning (photogrammerty) and scanning electron microscopy. The comparative analysis of the acquired data, together with information on extant pterygotes, will allow for the reconstruction of the ancestral states of the flight apparatus of Pterygota as well as its subgroups. This will substantially extend our knowledge and understanding of the evolution of the insects, the group that by far comprises the largest number of species among all organisms.