A well-preserved fossil of two dinosaurs locked in a deadly battle is expected to go for $7 million to $9 million at auction later this year, but the sale is already brewing controversy.



The Cretaceous combatants in the fossilized duel are Nanotyrannus lancensis, a tiny Tyrannosaurus rex, and Chasmosaurine ceratopsian, a close relative of the Triceratops. Both stood about 8 feet (2.4 meters) tall, measured between 25 and 35 feet (7.6 to 10.6 meters) long and suffered fatal wounds in the fight. The Chasmosaurine skull is pierced with Nanotyrannus teeth and the Nanotyrannus skull and chest seem to have been kicked in.

In announcing the Nov. 19 sale, the auction house, Bonhams, said the dinosaurs "may hold the key to answering one of the most puzzling questions for paleontologists today" — whether Nanotyrannus represents a separate genus or just a T. rex juvenile. [Paleo-Art: Dinosaurs Come to Life in Stunning Illustrations]

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"The Nanotyrannus involved in the 'Dueling Dinos' is only the second example ever found, and by far the most complete, offering the best hope to date of answering this pressing scientific question," Bonhams said in a press statement.

The fossil could be purchased by a museum or by a private individual who loans it to an institution, but it's not a guarantee that it will end up in the hands of scientists, and many paleontologists object to the sale and collection of such specimens.

Earlier this year, the fossilized skeleton of an Asian relative of T. rex known as Tarbosaurus bataar was returned to Mongolia after it showed up on the auction block (by way of the black market) and sparked an international custody battle. Unlike the Mongolia case, the dinosaur bones up for sale at Bonhams were found on private land in the United States and legally excavated by fossil prospectors. Clayton Phipps, a fossil hunter who calls himself Dino Cowboy, discovered the dinosaurs on his neighbor's land in the Hell Creek formation Montana in 2006, the New York Times reported.

Some scientists argue that high prices may encourage fossil-looting on federal lands and in places like Mongolia. They also worry that hurried excavations by commercial hunters threaten to destroy important, but less glamorous, contextual evidence, according to the Times. Jack Horner, a dinosaur paleontologist at Montana State University, was quoted as saying he considered the fossil headed for auction "worthless" since it was not collected as a scientific specimen.

Meanwhile, fossil hunters argue that they find specimens that would have otherwise been unknown to scientists or left to deteriorate. A fossil dealer involved with the "Dueling Dinos," Peter Larson of the Black Hills Institute of Geological Research, told the Times that Phipps excavated the fossils to the highest standard, saying, "I would put our skills up against any museum."

Follow Megan Gannon on Twitter and Google+.Follow us @livescience, Facebook and Google+. Original article on LiveScience.com.



