'Duelling dinosaurs' fossil for auction in New York
15 November 2013 Last updated at 11:33 GMT
Two dinosaurs thought to have been locked in combat when they died are to be auctioned in New York next week.
Thomas Lindgren, of auction house Bonhams described the pair as being "so important to science because of the fact they were found in a context that appears to be they killed each other."
The 17-metre fossilised skeletons were found on a Montana ranch in 2006 and are expected to reach up to $9m (£5.6m).