Scientists just heard a cricket sing after 165 million years

Scientists have reconstructed the chirps of insects that lived 165 million years ago, and at least one of those calls would have been too high-pitched for any human to hear. A team led in part by Thorin Jonsson, a bioacoustician at the University of Graz in Austria, studied 20 fossilized Jurassic insects found in Inner Mongolia, China, their wings still intact after all this time. The remains belong to nine species related to crickets and katydids. Crickets do not sing so much as play an instrument, rubbing ridged body parts together in a process called stridulation. The researchers counted the tiny teeth on each fossil wing, ran laser scans of modern insects, and fed the shapes into an A.I. model that predicted each call. Most landed around five kilohertz, clear chirps rather than buzzes. One katydid relative, Sigmaboilus peregrinus, reached 22 kilohertz, an ultrasonic pitch, and it lived millions of years before the first bats. "The world during the Jurassic Period was acoustically far richer and more diverse than previously thought," Jonsson said.