Slashdot Mirror
Oldest Fossilised Winged Insect Yet Discovered
tr0llb4rt0 writes "The Scientific American reports on an article in Nature (paid subscription required for full text) on how the fossilised mouth parts of an insect discovered in Scotland in 1928 has turned out to be the oldest winged insect yet discovered, pushing back the age of the earliest appearance of winged insects nearly 80 million years.
Previos fossils of winged insects have dated to around 330 million years and scientist believe this new discovery lived between 408 and 438 million years ago. "
The article is pretty sketchy on details, so here's something that will help a little. Now here's the most important part from that article, "Rhyniognatha could have had wings, say the authors, but this is impossible to confirm since the wings themselves are missing."
How can they tell that these mandibles are from a winged insect when there are no wings fossilized?
Winged insects and silverfish (the closest realtice of the winged insects) share several advanced traits. One is how the mandible attaches to the head capsule. This type of mandible attaches by two point and is called 'dicondylic'.
The fossil mandibles are clearly dicondylic, and are also of a type not known from silverfish at all. They are of a broad chewing type more associated with 'higher' insects such as grasshoppers or cockroaches. Since there are no wings, they can't be abolutely sure if this was a winged insect or an unknown wingless insect more closely related to winged insects that to silverfish.
When discussing organisms at the genus level and up, you usually find that looks of seemingly unrelated characteristics are found together. Iirc from my zoology classes a decade-plus ago, mouthparts are pretty variable in insects, so it's not that unlikely that going an insect could be identified as a flyer from just the mouth parts.
Of course, since all fossils are fakes, this discussion is probably moot:)
"Bugger this, I want a better world." - Jenny Sparks