REANALYSIS AND EXPERIMENTAL EVIDENCE INDICATE THAT THE EARLIEST TRACE FOSSIL OF A WINGED INSECT WAS A SURFACE-SKIMMING NEOPTERAN
Article first published online: 10 AUG 2012
© 2012 The Author. Evolution© 2012 The Society for the Study of Evolution.
Volume 67, Issue 1, pages 274–280, January 2013
How to Cite
Marden, J. H. (2013), REANALYSIS AND EXPERIMENTAL EVIDENCE INDICATE THAT THE EARLIEST TRACE FOSSIL OF A WINGED INSECT WAS A SURFACE-SKIMMING NEOPTERAN. Evolution, 67: 274–280. doi: 10.1111/j.1558-5646.2012.01743.x
- Issue published online: 4 JAN 2013
- Article first published online: 10 AUG 2012
- Accepted manuscript online: 21 JUL 2012 09:06AM EST
- Received: April 13, 2012, Accepted: July 3, 2012
- flight evolution;
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.