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Imagine standing in a forest 165 million years ago. Dinosaurs may have been moving through the vegetation, but they weren’t the only animals making noise. High above the forest floor and among the plants, ancient cricket and katydid relatives were producing calls that may have filled the Jurassic night.

Now, scientists have reconstructed what some of those 165-million-year-old Jurassic insect sounds may have been like.

The research, published in the Proceedings of the National Academy of Sciences, combines fossil evidence with biomechanics, computer simulations, evolutionary analysis and artificial intelligence to recreate a portion of a lost Jurassic soundscape.

The discovery is especially intriguing because at least one of the ancient insects appears to have communicated using ultrasonic frequencies above 20 kilohertz—suggesting that insects were using ultrasound long before the evolution of bats.

A Jurassic Soundscape Hidden in Fossil Wings

Reconstructing sounds from the Jurassic is extremely difficult. Soft tissues and vocal organs rarely survive millions of years, meaning scientists generally cannot determine exactly what extinct animals sounded like.

Insects provide an unusual exception.

Some cricket and katydid relatives produce sound by rubbing specialized structures on their wings against each other. These structures, known as a stridulatory file and plectrum, can sometimes survive in exceptionally preserved fossils.

Those tiny structures effectively act as a biological recording of how an insect produced sound.

The new research examined 20 fossilized ensiferan insects representing nine species from the Jiulongshan Formation in Inner Mongolia, China. The fossils date to approximately 165 million years ago during the Middle Jurassic.

How Scientists Recreated the Ancient Insect Sounds

The researchers couldn’t simply play a fossil wing like an ancient recording.

Instead, they had to work backward from the physical evidence.

The team combined several scientific techniques, including:

• Fossil analysis to measure the insects’ wing structures
• Phylogenetic analysis comparing extinct insects with nearly 100 living species
• Laser Doppler vibrometry to measure vibrations in modern insect wings
• Numerical simulations to model how fossil wings could have vibrated
• Machine learning to estimate characteristics of the ancient insects’ calls

The result is not a literal recording of a Jurassic insect. Instead, it is a scientifically informed reconstruction of what those calls were likely to have sounded like.

That distinction is important: AI didn’t “hear” the Jurassic. It helped researchers use measurable fossil anatomy and modern biological relationships to model the most plausible acoustic signals.

Some Jurassic Insects May Have Used Ultrasound

One of the most surprising discoveries involves the frequency of the insects’ calls.

Many of the reconstructed species appear to have produced relatively pure tones around 5 kilohertz, within the general range of sounds produced by some modern crickets and related insects.

But one species, Sigmaboilus peregrinus, appears to have produced sounds above 20 kHz.

That frequency is generally considered the beginning of the ultrasonic range for humans.

The finding is important because it pushes evidence for insect ultrasonic communication deep into the Jurassic. The researchers argue that ultrasonic signaling existed long before bats appeared in the fossil record during the Eocene.

Bats May Not Have Invented the Ultrasound Arms Race

For years, one possible explanation for the evolution of ultrasonic communication in insects has been the emergence of bats.

Bats use echolocation, which operates at ultrasonic frequencies, and scientists have proposed that insects may have evolved ultrasonic hearing and communication as a response to bat predation.

The new findings complicate that explanation.

If Jurassic insects were already producing ultrasonic calls around 165 million years ago, they were doing so tens of millions of years before bats appeared.

That means bats could not have been the original driver behind all insect ultrasound.

Instead, the researchers suggest that early mammals and other predators may have created evolutionary pressure that encouraged insects to change their acoustic signals.

Why Would an Insect Use Ultrasound?

Sound is useful for communication, but it also creates a problem: predators can hear it.

A male insect calling for a mate has to make its signal noticeable to potential partners without making itself too easy for predators to locate.

High-frequency or ultrasonic signals could have provided one possible solution.

The researchers suggest that some Jurassic insects may have used different frequencies to communicate while reducing the risk of being detected by predators. Different species could also occupy separate acoustic frequencies, reducing interference between their calls.

This could have created an evolutionary arms race between singing insects and animals capable of hearing them.

The Jurassic Forest May Have Been Surprisingly Noisy

The popular image of the Jurassic often focuses on enormous dinosaurs, but the new research provides another perspective.

The forests of the Middle Jurassic may have contained a complex acoustic ecosystem filled with insect calls at different frequencies.

Rather than a silent backdrop for dinosaurs, the ancient landscape may have included multiple layers of sound generated by insects communicating, competing and avoiding predators.

The researchers found substantial diversity in the predicted frequencies and call patterns of the fossil insects. Specialized wing structures and differences in wing size appear to have contributed to that acoustic diversity.

What Did Jurassic Insects Actually Sound Like?

Scientists have previously reconstructed the calls of individual Jurassic insects.

For example, research published in 2012 reconstructed the song of Archaboilus musicus, a 165-million-year-old katydid relative, at approximately 6.4 kHz. The researchers concluded that its musical, pure-tone call was probably used by males to attract females.

The new research goes much further.

Rather than focusing on a single species, scientists reconstructed a broader collection of insects to investigate what an entire ancient soundscape may have been like.

That makes the study particularly exciting for paleontology because it moves beyond asking “What did this extinct animal sound like?”

Scientists can begin asking a much bigger question:

“What did an entire prehistoric ecosystem sound like?”

AI Is Opening a New Door for Paleontology

The study also demonstrates how artificial intelligence and advanced computer modeling are changing fossil research.

Traditionally, paleontologists have relied heavily on bones, teeth, footprints and other physical structures to reconstruct extinct animals.

But increasingly, researchers are looking at how fossils can preserve evidence of behavior.

In this case, microscopic features on insect wings provided clues about communication. Computer models and machine-learning techniques then helped transform those physical clues into predictions about sound.

The researchers’ supplementary dataset includes modeling materials and code associated with the reconstruction.

This approach could eventually be applied to other extinct animals and ecosystems where physical structures preserve clues about movement, communication or sensory abilities.

A New Way to Experience the Age of Dinosaurs

The ability to reconstruct ancient insect calls doesn’t mean scientists can perfectly recreate the entire Jurassic soundscape.

There are still uncertainties. The fossil record is incomplete, and researchers must make assumptions about how extinct structures functioned based on modern relatives and biomechanical models.

Nevertheless, the research provides a remarkable window into an ecosystem that disappeared tens of millions of years before humans existed.

It suggests that sophisticated acoustic communication was already developing among insects during the Jurassic—and that the evolutionary battle between predators and prey may have been shaping hearing and communication systems long before bats entered the picture.

Final Thoughts

The discovery of 165-million-year-old Jurassic insect sounds gives scientists an extraordinary new way to explore Earth’s deep past.

By studying fossilized wings and combining them with laser measurements, evolutionary analysis, computer simulations and AI, researchers have reconstructed likely calls from ancient cricket and katydid relatives.

Most surprisingly, one species appears to have communicated above 20 kHz, providing evidence that ultrasonic insect communication predates bats by tens of millions of years.

The research reminds us that the Jurassic wasn’t simply an age of giant dinosaurs. It was a complex ecosystem filled with countless smaller creatures communicating, hunting and competing.

For the first time, scientists are beginning to turn some of those fossilized clues into sound—and potentially allowing us to hear echoes of a world that vanished 165 million years ago.