A fossil dealer has pleaded guilty to illegally removing a dinosaur skeleton from Mongolia—where the fossils are the property of government—that he tried to auction for $1 million. Eric Prokopi, 38, had been charged with conspiracy, making false statements, and interstate transportation of stolen property. His scheme was discovered by the American Museum of Natural History's chairman of paleontology, who saw the auction listing and became very alarmed.

Dr. Mark A. Norell, the curator and chairman of paleontology at the AMNH, wrote an open letter to Heritage Auctions, which had put a $1 million estimate on the Tyrannosaurus fossil.

It is with great concern that I see Mongolian dinosaur materials listed in the upcoming (May 20) Heritage Auctions Natural History catalogue. For the last 22 years I have excavated specimens Mongolia in conjunction with the Mongolian Academy of Sciences. I have been an author on over 75 scientific papers describing these important specimens. Unfortunately, in my years in the desert I have witnessed ever increasing illegal looting of dinosaur sites, including some of my own excavations. These extremely important fossils are now appearing on the international market.

In the current catalogue Lot 49317 (a skull of Saichania) and Lot 49315 (a mounted Tarbosaurus skeleton) clearly were excavated in Mongolia as this is the only locality in the world where these dinosaurs are known. The copy listed in the catalogue, while not mentioning Mongolia specifically (the locality is listed as Central Asia) repeatedly makes reference to the Gobi Desert and to the fact that other specimens of dinosaurs were collected in Mongolia. As someone who is intimately familiar with these faunas, these specimens were undoubtedly looted from Mongolia. There is no legal mechanism (nor has there been for over 50 years) to remove vertebrate fossil material from Mongolia. These specimens are the patrimony of the Mongolian people and should be in a museum in Mongolia. As a professional paleontologist, am appalled that these illegally collected specimens (with no associated documents regarding provenance) are being sold at auction.

In other words, Prokopi, who is called a "commercial paleontologist," thought no one would question the provenance a rare and 75% complete skeleton in a highly publicized auction.

Prokopi had claimed that the dinosaur came from Great Britain, but yesterday he told a judge, "I forwarded a few shipments of fossils of Mongolian origin from Great Britain to the U.S. that were mislabeled. I imported and transported Mongolian fossils that were exported from Mongolia without the proper permits." He had also listed the dinosaur as being worth $15,000 when importing it!

He agreed to surrender the skeleton, as well as five other dinosaur skeletons, and help authorities investigate fossil smuggling in his plea deal. Prokopi faces up to 17 years in prison; his sentencing is in April.