Actor Nicolas Cage has agreed to return the skull of a Tyrannosaurus bataar he purchased—as an anonymous buyer—from a luxury natural history auction in 2007. The skull turns out to have been stolen from the Gobi Desert in Mongolia. Cage bought the skull from the I.M. Chait Gallery in Beverly Hills and was contacted by the Department of Homeland Security last year. The actor has agreed to turn the skull over to its rightful nation.

Preet Bharara, a U.S. attorney in Manhattan, filed a civil forfeiture complaint last week in order to take possession of the stolen skill. The lawsuit does not name Cage or accuse him of any wrongdoing, and he voluntarily agreed to give up the skull. He did receive a certificate of authenticity with his purchase, but the I.M. Chait Gallery had purchased and sold an illegally-obtained dinosaur skeleton from paleontologist Eric Prokopi, notorious seller of such artifacts. The skull is authentic, yes—but it is in the wrong land.

The gallery is also not accused of any wrongdoing, and Prokopi has helped prosecutors recover at least 17 other fossils as part of his guilty plea.

“Cultural artifacts such as this bataar skull represent a part of Mongolian natural cultural heritage,” says a special agent the Bharara’s office, Glenn Sorge. “[This skull] belongs to the people of Mongolia. These priceless antiquities are not souvenirs to be sold to private collectors or hobbyists.”

Cage is himself an avid collector of many things including cars and comic books; he outbid fellow actor Leonardo DiCaprio for the bataar skull. He sold a like-new copy of Action Comics No. 1, the comic book that includes the very first appearance of Superman, for $2.1 million.

However, it is important that the skull is returned to Mongolia, and not just because of its cultural significance, but because of its scientific potential. Illegal sales of dinosaur artifacts worry historians and paleontologists because they make it harder to learn about dinosaurs and how they lived.

“We’re losing science, we’re losing education, we’re losing valuable specimens,” says Kevin Padian, a paleontologist at the University of California.

A relative of the widely-recognized Tyrannosaurs rex, the bataar lived 70 million years ago. Remains of the species have as yet only been discovered in Mongolia, where at least 12 fossils, including three entire bataar skeletons, have been found.