Biologists have recreated the real sound of Jurassic period forests for the first time

An international team of biologists has recreated the soundscape of Jurassic-period forests that existed 165 million years ago. The researchers published audio recordings of the chirping of nine extinct insect species in the journal Proceedings of the National Academy of Sciences, as reported by The New York Times.

The scientists, led by Jun-Jie Gu, a professor of entomology at Sichuan Agricultural University, studied fossilized remains of ancestors of crickets and grasshoppers found in Inner Mongolia in China. The ancient insects produced sounds by rubbing their wings against each other. To accurately reproduce their chirping, the biologists used laser Doppler vibrometry and high-speed cameras to analyze modern relatives of these species. The resulting data were fed into a computer model with machine learning algorithms, which calculated the sound based on the physical parameters of the fossilized wings.

It was discovered that one of the species, named Sigmaboilus peregrinus, emitted ultrasonic signals beyond the range of human hearing. This discovery refutes the popular theory that insects developed ultrasound as a defense against bats. Bats appeared on Earth approximately 100 million years after these ancient species went extinct. According to the study's authors, the insects created their own acoustic niches so that their signals would not blend with the chirping of their kin, and also avoided attracting the attention of early mammals.

For a long time, paleontologists were unable to accurately recreate the sounds of dinosaurs, since the soft tissues of their vocal organs are rarely preserved in geological strata. In popular culture, for example in the film "Jurassic Park," the voices of ancient reptiles were entirely invented by artists. This new study has for the first time provided the scientific community with a reliable acoustic landscape of that era, based on actual fossil materials.

The recreated sounds have already found practical application: for several years, the researchers assisted the creators of the Netflix documentary miniseries "Life on Our Planet" so that the producers could use the most accurate and realistic soundtrack possible in the project.