The Archeopteryx - here an illustration by John Doncaster - ...
Read out The archaeopteryx, a bird of prey, had a similar level of hearing as the emus that lives today: it is best to hear frequencies of around 2, 000 hertz, scientists in the United Kingdom, Germany and the USA found out in an analysis. The researchers analyzed computed tomography of the inner ear of 59 reptiles and birds that still live today, and used it to develop a model that allows conclusions to be drawn about the animal's hearing. This model they applied to extinct species such as the primitive bird Archeopteryx. The scientists had 59 animal skulls in their study? from crocodiles to lizards and turtles to birds like owls, pigeons and emus? examined in a three-dimensional and high-resolution computed tomography. From the pictures, the researchers determined the length of the helix? the bony part of the inner ear, which harbors the actual hearing organ with the fine hair cells, which convert mechanical vibrations into nerve signals.

The researchers were able to observe a linear relationship between the length of this helical flight and the frequency range in which the animals' hearing is most sensitive. Applied to the hearing aid of the more than 140 million years old Archeopteryx it was found that the original bird heard frequencies between 600 and 3, 400 Hertz, with the maximum of hearing at about 2, 000 Hertz. Thus, the Archeopteryx heard about as good as the Emu, which is among the less sensitive listeners among today's birds.

Since hearing also affects social life and vice versa, it may be possible to draw conclusions about the way of life of these primitive birds with the help of these results, the researchers speculate. Species that form large social groups have a more complicated communication about sounds, and this in turn is related to hearing, explains Paul Barrett, one of the scientists involved.

Stig Walsh (Museum of Natural History, London) et al .: Proceedings of the Royal Society B, online pre-publication, DOI: 10.1098 / rspb.2008.1390 ​​ddp / Ulrich Dewald ad


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