Here is an insect wing. The veins of insect wings form closed cells whose patterns can be used to identify the insect. The type of insect this wing belonged to is not known. Based on the fossil record, insects developed wings sometime between 400 and 320 million years ago. How and why they did is not known. Note some iridescence on parts of the wing. The length of the wing is 7.9 mm.
Equipment used: Canon EOS Rebel T5i with a standard zoom lens (EF-S 18-55 mm) on a 49 mm long extension tube.