With Fossilized Wings: Scientists Reconstruct Sounds of Insects That Lived 165 Million Years Ago

Amidst the footsteps of dinosaurs and the rustling of ferns, Jurassic forests were not silent; they were filled with the chirps of grasshopper-like insects, some of which emitted sounds beyond human hearing.

According to a study published in the scientific journal PNAS, an international team reconstructed this soundscape from 20 winged fossils representing nine species discovered in the Jiulongshan Formation in Inner Mongolia, China.

These insects produced sounds without vocal cords by rubbing serrated parts of their wings against each other, much like playing a musical instrument.

Researchers therefore examined the number of fine teeth, the distances between them, and the size of the vibrating area, comparing them with the sound-production mechanisms of contemporary insects using laser measurements. They then integrated the results with digital simulations and an artificial intelligence model to estimate the rhythm and pitch of each call.

The models indicated that most species emitted relatively low-pitched pure tones around 5 kilohertz. However, the insect known as “Sigma boylei” may have produced calls between 20 and 22 kilohertz, at or slightly above the upper limit of human hearing.

These frequencies may have helped the insects communicate over long distances, away from other predators, or distinguish their calls amidst the forest’s “choir.” Researchers emphasize that the recordings are not preserved original sounds but rather a plausible scientific reconstruction of what those insects likely produced.