A Florida fossils dealer pleaded guilty to smuggling charges Thursday and agreed to give up a celebrated $1 million dinosaur skeleton seized by the U.S. government earlier this year for its eventual return to Mongolia.

Eric Prokopi, 38, said he would surrender the 70 million-year-old Tyrannosaurus bataar skeleton known as “Ty” and give up any claims to six other dinosaurs and various other bones in a cooperation deal that might win him leniency from charges that carry a potential prison sentence of up to 17 years.