Pterothoracic structures of the minute ptiliid Nephanes titan were examined and described in detail. Effects of miniaturization and the phylogenetic and functional background are discussed. Apomorphies shared with Hydraenidae are the large metascutal shield, the fringe of setae along the posterior edge of the wings, and the fusion of the mesoventrite with the mesanepisternum. Autapomorphies of Ptiliidae are the highly modified feather-like wings, the strongly elongated alacristae, the loss of the mesotrochantin, the enlarged metathoracic pleural wing joint, and the simplification of the direct flight musculature. Most phylogenetically relevant features are linked with miniaturization, especially the modifications of the wings and skeleton, for instance the reduced wing membrane or the simplified metanotum without distinct notal wing processes. Ptiliids show flight characteristics that distinctly differ from what is known in other insects, such as an unusually high amplitude of beats of the elytra, and a unique trajectory of wing return movements, as well as the presence of upper and lower claps. A comparison of cross-sections of ptiliid principal flight muscles with those of larger staphyliniform beetles suggests that muscles of the tiniest beetles are relatively smaller. This may reflect the higher aerodynamic efficiency of ptiliid feather wings compared to the common membranous wings found in other groups.

中文翻译：

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最小的甲虫之一的运动装置-Nephanes titan（鞘翅目，P科）的胸部骨骼肌系统。

检查并详细描述了微小上睑Nephanes titan的翼胸结构。讨论了微型化的影响以及系统发育和功能背景。与Hydraenidae共享的无性生殖是大型的后盾形盾构，沿翅膀后缘的刚毛边缘，以及中胚轴与间皮膜的融合。t科的亚型包括高度修饰的羽毛状翅膀，强烈伸长的乳酸菌，中膜降钙素的丧失，胸壁胸膜后翼联合增大以及直航肌肉组织的简化。系统发育上最相关的特征与小型化有关，尤其是机翼和骨骼的修饰，例如，没有明显的公称翼突的简化的机翼膜或简化的胸骨。蝶形虫的飞行特征与其他昆虫的飞行特征明显不同，例如鞘翅目动物的节拍异常高振幅，机翼返回运动的独特轨迹以及上下拍手的存在。翼状主要飞行肌肉的横截面与较大的葡萄状甲虫的横截面的比较表明，最小的甲虫的肌肉相对较小。这可能反映出与其他组中常见的膜状翅相比，上翅翅翅的空气动力学效率更高。翼状主要飞行肌肉的横截面与较大的葡萄状甲虫的横截面的比较表明，最小的甲虫的肌肉相对较小。这可能反映出与其他组中常见的膜状翅相比，上翅翅翅的空气动力学效率更高。翼状主要飞行肌肉的横截面与较大的葡萄状甲虫的横截面的比较表明，最小的甲虫的肌肉相对较小。这可能反映出与其他组中常见的膜状翅相比，上翅翅翅的空气动力学效率更高。