Researchers reconstruct insect sounds from 165 million years ago

An international research team, including biologists from the University of Graz and Capital Normal University, has successfully reconstructed the acoustic environment of the Middle Jurassic period, approximately 165 million years ago. By analyzing 20 fossils of nine different species of katydids found in Inner Mongolia, China, researchers used morphological analysis, mechanical simulations, and AI-supported modeling to recreate their mating calls.

The study reveals that the Jurassic soundscape was highly diverse. While five species produced pure, low-frequency tones between 5 kHz and 7 kHz, others produced higher frequencies. Most significantly, the research confirms that certain insect species were already communicating via ultrasound, with frequencies reaching up to 20.5 kHz. This discovery proves that ultrasonic communication existed over 100 million years before the evolution of bats, challenging previous theories that such communication evolved specifically as a response to bat predation.

The researchers suggest that the use of narrow-spectrum “pure tones” may have been an evolutionary adaptation to evade predators, as the middle-ear structures of early Jurassic mammals were likely less capable of pinpointing the location of such specific sounds.