Department of Biology, Pennsylvania State University, University Park, PA 16802, USA.
Evolution. 2013 Jan;67(1):274-80. doi: 10.1111/j.1558-5646.2012.01743.x. Epub 2012 Aug 10.
A recent description and analysis of an imprint fossil from the Carboniferous concluded that it was made by a mayfly landing in sediment at the edge of water. Here, I reanalyze that trace fossil and supply experimental evidence regarding wing traces and behavior. The thorax of the trace maker lacked structures characteristic of mayflies, but closely matches a modern neopteran insect family (Taeniopterygidae, Plecoptera) little changed from Early Permian fossils. Edges of the folded wings of live Taeniopteryx leave marks on sediment closely matching marks in the trace fossil. Faint marks lateral to and beyond the reach of meso- and metathoracic legs match the location where wings of surface-skimming Taeniopteryx stoneflies lightly touch the sediment when these insects skim onto wet ground at shorelines. Dimensions of the thorax of the trace indicate relatively weak flight ability compared to fossils from the Early Permian, making doubtful the hypothesis that the trace maker was flight capable. Ultimately, this fossil best fits a scenario in which a neopteran insect skimmed across the surface of water, then folded its wings. Surface skimming as a precursor to the evolution of flight in insects is supported by this fossil evidence of skimming behavior in a Carboniferous insect.
最近对石炭纪印痕化石的描述和分析得出结论，它是由一只蜉蝣在水边的沉积物中降落时形成的。在这里，我重新分析了那个痕迹化石，并提供了有关翅膀痕迹和行为的实验证据。痕迹制造者的胸部缺乏蜉蝣的特征结构，但与现代新翅目昆虫家族（石蛃目，蜉蝣目）非常相似，这些昆虫自早二叠世化石以来几乎没有变化。活体 Taeniopteryx 折叠翅膀的边缘在沉积物上留下的痕迹与痕迹化石中的痕迹非常匹配。中胸和后胸腿无法触及的侧面和外侧的微弱痕迹与 Taeniopteryx 石蝇掠过水面时翅膀轻轻触及沉积物的位置相匹配，当这些昆虫在岸边滑到湿地上时，它们的翅膀会掠过水面。痕迹的胸部尺寸表明与早二叠世的化石相比，飞行能力相对较弱，这使得该痕迹制造者能够飞行的假设变得值得怀疑。最终，这个化石最符合这样一种情况，即一只新翅目昆虫在水面上掠过，然后折叠翅膀。这种昆虫在石炭纪的掠食行为的化石证据支持了昆虫在飞行进化之前的水面掠食行为的假设。
