• There was 165 million years ago

The reproduction of the singing, the insect was used to attract females, was made possible by the discovery in China of the fossil of a copy

London, England (06/FEB/2012).-the Colombian Fernando Montealegre Zapata, academic at the school of Biological Sciences English at Bristol University, has been recreated for the first time the song of a cricket that existed ago 165 million years ago, in the Jurassic period.

The details of that experiment, that has allowed to discover new details of the evolution of crickets, are published today in the American scientific journal “Proceedings of the National Academy of Sciences” (PNAS).

Playback singing, that the insect (like current crickets) used to attract females, was made possible by the discovery in China of the fossil of a specimen in perfect condition dating back to the Jurassic period.

“I had never worked with fossils and it has been an exciting experience,” he told Efe Montealegre, world expert in Biomechanics of the sounds in insects.

The fossil, discovered by a group of paleontologists led by Junjie Gu, Chinese University of Peking, and named “Archaboilus musicus”, is a predecessor species of crickets today known as “catídidos”, who live in the bushes.

The catídidos differ from other crickets because they have asymmetric wings and produce songs with ultrasound, targeting female specifically attuned to that channel, to elude predators such as bats, says the expert.

Another family of crickets, found at ground level, has symmetrical wings and they are much more noisy for the human ear, with musical songs at low frequencies.

Crickets of all kinds emit his singing with a zest a lime with dientecillos in the top right with the left lower wing.

To recreate the sound of the fossil, the Colombian expert, together with his colleague in Bristol Robert Daniel, studied its morphological characteristics, which differ from the current catídidos that its wings were symmetrical at this time and he had instruments estriduladores (of sound production) across its surface.

“Knowing the morphology of the fossil, I went to the crickets of tree existing, the closest, who sing in high frequency, and I took a curve calibration for sixty existing species, computing the frequency at which each species sings,” he explained.

Through mathematical calculations and with reference to a current catídidos located in Madagascar, he concluded that the insect was producing “music songs with the issuing of unique and pure frequencies”.

Thus he managed to reproduce the supposed singing of the Jurassic cricket, with a tone at a rate of 6.4 kHz in which each unit of sound lasts approximately 16 milliseconds.

“In the age of the fossil was no bats, which is why the Archaboilus should sing more repeatedly than species now”, make it at intervals and with different intensity to mislead those predators, told Efe.

In the process of reproduction of the tone is found out many things about this primitive species, said Montealegre.

It was concluded, for example, that this animal was probably nocturnal, and the ear of the female had to be very already developed at that time to locate the male in an environment which, supposedly, was very noisy.

Although 165 million years ago there was no bat – predators of the current catídidos-, had another predator that could possibly capture the frequency of that primordial grillo, an insectivorous mammal called morganucodón.

According to experts, with the arrival of bats around 65 million years ago, the tree crickets were adapted and began to develop ultrasonic, while also appears the asymmetry of the wings.