Flies and mites are usually pests – except, perhaps, when they’re really old. For the international team of scientists that has found one fly and two mites that lived 230 million years ago trapped in amber droplets, the Triassic critters are an important discovery that will pave the way to a better understanding of insect evolution.
“There was a huge change in the flora and fauna in the Triassic because it was right after one of the most profound mass extinctions in history, at the end of the Permian,” American Museum of Natural History entomologist David Grimaldi said in a press release, referring to the mass-extinction event 252 million years ago that led to the death of 96 percent of marine life and 57 percent of insect families. “It’s an important time to study if you want to know how life evolved.”
To find the bugs, the team excavated miniscule amber droplets from the Dolomite Alps in northeastern Italy. They then examined about 70,000 of the droplets for animals or plants that might be trapped within them, leading them to the remnants of the fly and mites. It was an arduous process, given that each droplet is only between 2 and 6 millimeters long. But it’s one with a big payoff: the three arthropods are 100 million years older than any previously discovered amber-preserved arthropods, though they’re not the oldest bugs ever found. Those fossils date back to the early Cambrian period, about 500 million years ago. The findings are published in the Proceedings of the National Academy of Sciences.
Despite their age, the ancient mites aren’t too different from the mites we have today. “You would think that by going back to the Triassic you’d find a transitional form of gall mite, but no,” Grimaldi said in a press release. “Even 230 million years ago, all of the distinguishing features of this family were there — a long, segmented body; only two pairs of legs instead of the usual four found in mites; unique feather claws.”
Though they’ve endured well, the critters were also very adaptable. While almost all of today’s mites eat flowering plants, the ancient mites probably fed on a conifer from an extinct family – which means they simply shifted their dining habits when flowering plants came along.
Unfortunately, the scientists couldn’t identify the fly specimen because only its antennae remained intact. But NBC News reports that the team is hoping to find more droplets in Europe and North America. It’s surely no small task, given that a search of 70,000 droplets yielded just three specimens this time.