Winged Insects Appear Surprisingly Ancient
Perkins, S., Science News
New analyses of a fossil ignored for decades in a British museum suggest that winged insects may have emerged as early as 400 million years ago, tens of millions of years before scientists expected.
The fossil had been excavated near Rhynie, Scotland, and was first described in the late 1920s. While specimens from related species that were preserved intact at the same site have attracted more scientific notice, this microscopic remnant of an ancient insect's head received only a cursory examination and a name--Rhyniognatha hirsti--before it fell into obscurity.
Rhyniognatha's chewing mouthparts, or mandibles, are robust and triangular, and they sport toothlike projections, says David A. Grimaldi of the American Museum of Natural History in New York. He and his colleague Michael S. Engel of the University of Kansas in Lawrence describe the fossil in the Feb. 12 Nature.
Each 0.1-millimeter-long mandible was attached to the creature's head at two hinge points rather than one. This feature, which increases an insect's chewing power, is found today only in silverfish among insects that have no wings and in many winged insects, including dragonflies.
Unfortunately, the Rhyniognatha specimen doesn't include the body segment to which the wings would have been attached. …