Ancient mating song revealed
2 Mar 2012 by Evoluted New Media
The mating song of an extinct cricket that lived 165 million years ago has been bought back to life thanks to an international team of scientists.
Modern-day katydids or bush crickets produce mating calls by stridulation – rubbing a row of teeth on one wing against a plectrum on the other – but how their ancestors produced their song was unknown until researchers from Capital Normal University in Beijing found an exceptionally detailed bushcricket fossil from the Mid Jurassic Period.
The specimen – which came from a previously undiscovered species now named Archaboilus musicus – has such well-preserved wing features that the details of its stridulating organs were clearly visible under an optical microscope.
By comparing the anatomical construction of the fossil’s song apparatus to 59 living bushcrickets species, Dr Fernando Montealgre-Zapata and Professor Daniel Robert from the University of Bristol concluded the animal must have produced musical songs, broadcasting pure, single frequencies.
“This discovery indicates that pure tone communication was already exploited by some animals in the middle Jurassic,” Said Robert. “For Archaboilus, as for living bushcricket species, singing constitutes a key component of mate attraction.”
Robert said singing loud and clear advertises the presence, location and quality of the sing, which the female chooses to respond to or not. The single tone carries further and better, so may attract more females
Montealgre-Zapata followed biomechanical principles he discovered some years ago to determine that A. musicus sang a tone pitched at 6.4kHz, and that every bout of singing lasted 16 milliseconds. This enabled the song itself to be reconstructed.
“Using a low-pitched song, A. muscius was acoustically adapted to long-distance communication in a lightly cluttered environment, such as a Jurassic forest,” said Montealgre-Zapata. “Today, all species of katydids that use musical calls are nocturnal so musical calls in the Jurassic were also most likely an adaption to nocturnal life.”
Montealgre-Zapata says this research – published in Proceedings of the National Academy of Sciences – suggests the evolutionary mechanisms that drove modern bushcrickets to develop ultrasonic signals for sexual pairing and for avoiding the increasingly relevant echolocating predator.
http://www.youtube.com/watch?v=_59f5U4Z4JA
