'Dueling Dinosaurs' to sell at NYC auction

'Dueling Dinosaurs' skeletons to be auctioned in NYC for estimated $7M to $9M

Dueling Dinosaurs Auction

In this Thursday, Nov. 14, 2013, photo, the lower leg 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)

Dueling Dinosaurs Auction

In this Thursday, Nov. 14, 2013, photo, a model that recreates the position that two dinosaurs were discovered in 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)

Dueling Dinosaurs Auction

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. (AP Photo/Seth Wenig)

Dueling Dinosaurs Auction

In this Thursday, Nov. 14, 2013, photo, the jaw and skull of a nanotyrannus lancensis 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)

Dueling Dinosaurs Auction

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)

Dueling Dinosaurs Auction

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)

Dueling Dinosaurs Auction

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)

Dueling Dinosaurs Auction

In this Thursday, Nov. 14, 2013, photo, Claws of the nanotyrannus lancensis are 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)

Dueling Dinosaurs Auction

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)

Dueling Dinosaurs Auction

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)

NEW YORK (AP) -- Two fossilized dinosaur skeletons found on a U.S. ranch in 2006 are going on the auction block in New York City. They're expected to bring between $7 million and $9 million.

The nearly complete skeletons are described as the "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 sellers believe one may be a close relative of Tyrannosaurus rex. The other may be a new species similar to Triceratops.

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