Reconstruction of Jurassic insect acoustics

An international research team has reconstructed the acoustic environment of the Middle Jurassic period, approximately 165 million years ago, by analyzing fossilized wings from nine species of ensiferan insects found in the Jiulongshan Formation in Inner Mongolia, China.

Using morphological analysis, mechanical simulations, and AI-supported modeling, scientists studied the mechanism of stridulation—where insects rub ridges against a scraper on another wing—to recreate mating calls. The findings reveal a diverse Jurassic soundscape featuring both low-frequency tones and ultrasonic communication.

Notably, the research confirms that certain species utilized frequencies reaching up to 20.5 kHz. This discovery indicates that ultrasonic communication existed over 100 million years before the evolution of bats, challenging theories that such communication evolved primarily as a response to bat predation. Researchers suggest the use of narrow-spectrum ‘pure tones’ may have been an adaptation to evade predators, as early Jurassic mammals likely lacked the middle-ear structures required to pinpoint such specific sounds.