Above, the fossilized teeth running along the katydid’s left and right wings
that researchers used to reconstruct the creature’s call.
Well-preserved fossils can tell paleontologists myriad things, such as what color feathers dinosaurs had, how ancient spiders evolved, and what kind of microbes were around 3 billion years ago. The latest such revelation is rather whimsical, as well as being scientifically interesting. Scientists have been able to reconstruct the chirping of a Jurassic ancestor of modern katydids by examining the wings of an exquisitely preserved fossil specimen.
Katydids create their song by scraping one wing across the other, running a hard ridge of tiny teeth, like those on a comb, across the ridge on the opposite wing. The research team examined the size and shape of the teeth on the wings of Archaboilus musicus, as the Jurassic specimen is called, to come up with an estimate of the frequency of the sound that such scraping would have produced. They found that the resulting chirping would have fallen at 6.4 kilohertz, within the range of normal human hearing.
So, if you ever get the chance to travel back 165 million years, keep your ears pricked. You might hear something that sounds like this:
Image and video courtesy of Gu et al, PNAS