A group of scientists lead by American Museum of Natural History curator David Grimaldi has published their discovery of two amber-encased, 230-million-year-old insects from the Dolomite mountains in the Proceedings of the National Academy of Sciences.
Dating back to the Triassic period, the era of early dinosaurs and the mega-continent Pangea, the newly uncovered mites are 100 million years older than the oldest amber-encased insects known to the world before this discovery.
Out of 70.000 2-to-6mm droplets of amber from outcroppings in the Dolomite mountains, excavated by Eugenio Ragazzi and Guido Roghi of the University of Padua, three droplets were found to contain two mites and a portion of a fly.
Arthropods, a group encompassing spiders, flies, and other joint-legged insects, first evolved 250 million years ago, after one of the most devastating extinction periods in earth's history. Amber fossilisation, which has preserved the two new mite specimens in great detail, allows scientists to examine the earliest forms of arthropods.
Though the recently-discovered specimens have two fewer legs and modified mouths, they are otherwise identical to modern gall mites, found in bubbles on plant leaves. The fact that these very early examples of arthropod evolution are so similar to modern mites has challenged scientific notions of the gradual progression of evolution.
