A famed paleontologist who discovered the world's best preserved dinosaur has pleaded guilty to stealing fossils from federal land.

Nate Murphy entered the plea Tuesday in U.S. District Court in Great Falls. The 51-year-old is accused of taking more than a dozen dinosaur bones from U.S. Bureau of Land Management land near Malta without a permit.

Under the plea agreement, prosecutors will not seek jail time when he is sentenced July 9.

U.S. Attorney Bill Mercer says he hopes the case will deter others from committing similar crimes.

Murphy says he made a "mistake" in not accurately mapping where fossils were recovered.

Murphy gained fame when he discovered a mummified, 77-million-year-old duckbilled hadrosaur known as Leonardo in 2000.