Yang Nan, Ren Dong, Béthoux Olivier
College of Life Sciences, Capital Normal University, 105 Xisanhuanbeilu, Haidian District, Beijing 100048, People's Republic of China.
CR2P (Centre de Recherche en Paléontologie-Paris), MNHN, CNRS, Sorbonne Université, 57 rue Cuvier, CP48, 75005 Paris, France.
R Soc Open Sci. 2023 Oct 4;10(10):230904. doi: 10.1098/rsos.230904. eCollection 2023 Oct.
During its 320 Myr evolution, dragon- and damselfly (Odonata) wing morphology underwent intense modifications. The resulting diversity prompted comparative analyses focusing on phylogeny. However, homoplasy proved to plague wing-related characters. Concurrently, limited benefits were obtained from considering fossil taxa, similarly impacted. Herein, we investigate two aspects particularly affected by convergence, namely the acquisition of vein-like structuring elements derived from regular cross-venation, termed conamina; and the evolution of butter knife wing shape. Conamen implementation is found to be consistently linked with vein curvature sharpening, itself generating potential breaking points. Conamina therefore likely evolved to address wing integrity issues during ever-more-demanding flight performance. Moreover, an existing conamen is likely to trigger the acquisition of further, associated conamina. As for butter knife shape, previously documented in the extinct Archizygoptera and among damselflies, we report a new, 315 Ma occurrence with the rare species gen. et sp. nov. (family Haidilaozhenidae fam. nov.), from the Xiaheyan locality (China). The repeated acquisition of butter knife-shaped wing can be related to slow speed flight and, in turn, predator avoidance. In both cases of iterated regularities, the unique 'network-and-membrane' wing design proper to insects is found to compose a strong, constraining factor.
在其3.2亿年的演化过程中，蜻蜓目（包括蜻蜓和豆娘）的翅膀形态经历了剧烈的变化。由此产生的多样性促使人们进行了以系统发育为重点的比较分析。然而，同源性被证明困扰着与翅膀相关的特征。同时，考虑同样受到影响的化石类群所获得的益处有限。在此，我们研究了受趋同影响特别大的两个方面，即从规则的交叉脉序衍生而来的脉状结构元素（称为共脉）的获得；以及餐刀形翅膀的演化。我们发现共脉的形成与翅脉曲率变锐始终相关，而翅脉曲率变锐本身会产生潜在的断裂点。因此，共脉可能是为了解决在要求越来越高的飞行性能过程中的翅膀完整性问题而演化出来的。此外，现有的共脉可能会引发更多相关共脉的形成。至于餐刀形翅膀，之前在已灭绝的原蜻蜓目和豆娘中已有记载，我们报告了一个新的、距今3.15亿年的例子，来自中国下河沿地区的罕见物种（新属新种，海底捞针科，新科）。餐刀形翅膀的反复出现可能与慢速飞行有关，进而与躲避捕食者有关。在这两种反复出现的规律性情况中，昆虫特有的独特“网络和膜”翅膀设计被发现构成了一个强大的限制因素。
