This specimen is downright famous. Like one of the prehistoric horses, it has already been featured on a postage stamp. Moreover, in 1993, the original fossil was even taken into outer space on board the Space Shuttle Columbia. With a wing span of 25 to 30 centimeters, the bat Palaeochiropteryx tupaiodon, which this specimen represents, is the smallest, but also the most numerous bat at Messel. Computer-tomographic images of the inner ear show that the Messel bats were already capable of hearing ultrasound and thus were able to orient themselves in total darkness, just like their modern relatives.