Taking a fossil from a site or collection without proper permission is, in effect. stealing. The recent explosion in prices paid for the best fossil specimens has meant that cases of 'fossil-rustling' have tripled in the past 20 years. One of the most infamous is the so-called Maxberg torso specimen of Archaeopteryx, one of only seven or so fossils of this earliest known bird. The only specimen to be held as part of a private collection (in Pappenheim, Germany). the Maxberg mysteriously disappeared following the death of its owner Eduard Opitsch in 1991. Despite police investigations it has not been found and is now believed to have been privately sold.