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In this Thursday, Nov. 14, 2013, photo, Clayton Phipps points out some features of the nanotyrannus lancensis he discovered while the fossils are on display in New York. Two fossilized dinosaur skeletons found on a Montana ranch in 2006 are coming up for sale in New York City. The nearly complete skeletons are billed as the Montana Dueling Dinosaurs.
NEW YORK—Two fossilized dinosaur skeletons found on a Montana ranch in 2006 are going on the auction block in New York City. They're expected to fetch between $7 million and $9 million.

The nearly complete skeletons are billed as the "Montana Dueling Dinosaurs." The sellers say the dinosaurs—one a plant eater, the other a meat eater—appear to be locked in mortal combat.

They're being sold as one lot at Bonhams auction house on Tuesday.

The skeletons were discovered by a fossil hunter on a neighbor's ranch in an area where dinosaurs once roamed.

The sellers believe one may be a close relative of Tyrannosaurus rex. The other may be a new species similar to Triceratops.

In this Thursday, Nov. 14, 2013, photo, Clayton Phipps poses for a picture with one of the two "dueling dinosaurs" he discovered in New York. Two
In this Thursday, Nov. 14, 2013, photo, Clayton Phipps poses for a picture with one of the two "dueling dinosaurs" he discovered in New York. Two fossilized dinosaur skeletons found on a Montana ranch in 2006 are coming up for sale in New York City. The nearly complete skeletons are billed as the Montana Dueling Dinosaurs. ((AP Photo/Seth Wenig))

They hope a philanthropist buys them and donates them to a public institution.

In this Thursday, Nov. 14, 2013, photo, fossilized skin with hexagonal segments was discovered with the skeleton of a ceratopsian which is on display in
In this Thursday, Nov. 14, 2013, photo, fossilized skin with hexagonal segments was discovered with the skeleton of a ceratopsian which is on display in New York. Two fossilized dinosaur skeletons found on a Montana ranch in 2006 are coming up for sale in New York City. The nearly complete skeletons are billed as the Montana Dueling Dinosaurs. ((AP Photo/Seth Wenig))

In this Thursday, Nov. 14, 2013, photo, the skull of a ceratopsian is displayed in New York. Two fossilized dinosaur skeletons found on a Montana ranch in
In this Thursday, Nov. 14, 2013, photo, the skull of a ceratopsian is displayed in New York. Two fossilized dinosaur skeletons found on a Montana ranch in 2006 are coming up for sale in New York City. The nearly complete skeletons are billed as the Montana Dueling Dinosaurs. ((AP Photo/Seth Wenig))

In this Thursday, Nov. 14, 2013, photo a nanotyrannus lancensis fossil is displayed in New York, Thursday, Nov. 14, 2013. Two fossilized dinosaur skeletons
In this Thursday, Nov. 14, 2013, photo a nanotyrannus lancensis fossil is displayed in New York, Thursday, Nov. 14, 2013. Two fossilized dinosaur skeletons found on a Montana ranch in 2006 are coming up for sale in New York City. The nearly complete skeletons are billed as the Montana Dueling Dinosaurs. ((AP Photo/Seth Wenig))

In this Aug. 19, 2006 photo provided by Bonham’s, people work around two fossilized dinosaur skeletons found on a Montana ranch. The "Montana
In this Aug. 19, 2006 photo provided by Bonham's, people work around two fossilized dinosaur skeletons found on a Montana ranch. The "Montana Dueling Dinosaurs" will be auctioned by Bonhams next week. ((AP Photo/CK Preparations, Bonhams))