Rainbow Wings by Olmagon on DeviantArt (original) (raw)

307 million years ago during the late Carboniferous period among the branches of an ancient forest in what is now France, a small primitive spider just barely over a centimeter in legspan known as Palaeothele montceauensis gets temporarily dazzled and confused by the sudden multi-colored lights shining at it. A titanopteran insect called Theiatitan azari spreads its brilliantly-colored wings, each almost 3 centimeters long, as it prepares to take off into the Carboniferous skies. The spider will be fine, luckily for it the predatory large insect flew off before noticing it.

First drawing made for Prehistoric Flyers Week (mobile.twitter.com/EDGEinthewi…, the usual YouTube announcement video isn't here yet so that Twitter post must do for now). When one thinks of prehistoric flying animals, the pterosaurs are probably the first that come to mind (though an average guy without much paleontology knowledge probably knows them as inaccurate-looking "pterodactyls"). While the pterosaurs were the first vertebrates to develop powered flight, the insects had evolved wings and flight long before the Triassic period (when the first pterosaur lived), with the oldest confirmed specimen of a flying insect dating to the Carboniferous period, so for over 70 million years insects would've been the only animals in the air.

One extinct order of insects was Titanoptera, with species having lived mostly during the Permian and Triassic periods, but the oldest known titanopteran lived during the Carboniferous. Described from a fossil specimen of a wing found in France, Theiatitan lived 50 million years before the next oldest known Titanopteran and is currently the only one known from the Carboniferous, showing this order evolved earlier than once thought. The titanopterans may resemble modern mantises with their similar raptorial forelimbs, and they were similarly carnivorous and would have lived similar ambush predator lifestyles, but this extinct group is actually more closely related to crickets and grasshoppers. The one known wing is a bit under 3 centimeters long so I estimate the whole insect would be around the size of an Asian giant hornet. While that's quite large by modern insect standards, it was nothing compared to the biggest Carboniferous insects like the dragonfly relative Meganeura which had a wingspan rivaling a seagull. The largest titanopterans were also much bigger, like Gigatitan from the Triassic of Kyrgyzstan which had a wingspan over 35 centimeters. Gigatitan is also the best-known titanopteran, with its well-preserved remains giving a good idea of what these insects looked like.

The one single wing from Theiatitan has been researched quite well and reveals that the animal's wing was quite likely able to produce flashes of colored light in flight similar to the damselflies of the family Chlorocyphidae, retracting light through them and producing brilliant colors (though exactly what these colors were remains unknown). In those damselflies the light flashes are used for sexual display and to warn away rivals, which the titanopteran may have done as well. Other structures of the same wing also suggests Theiatitan could have used its wings to produce sound via crepitation in a way similar to its closest living relatives, grasshoppers and crickets. It seems very likely that this creature, and probably many other titanopterans, would have used their wings as communication and display structures, and Theiatitan is currently the oldest known animal to have wings that serve for communication. Quite fitting that the insect is named after Theia, a Titan in Greek mythology and the Goddess that gave jewels and gold their brilliance and shine.

As for Palaeothele, it is a primitive species of extinct spider in the Mesothelae suborder, the oldest extant suborder of spiders that today includes the tube-dwelling spiders of the Liphistiidae family. Originally named Eothele, that name was later found to already be used by a brachiopod so it was changed. And before anyone starts thinking of making a Walking With Monsters remake using this in place of their meothelae spider which was a outdated Megarachne, I'm just gonna mention that Palaeothele was tiny, with a main body length of 5 millimeters, and the full legs pan would be just over a centimeter, so it wouldn't be hunting primitive amniotes (if anything it would be prey for them).

First Theiatitan on DA too!