Dinosaur chase scene reconstructed
3 April 2014 Last updated at 08:19 BST
Scientists have digitally reconstructed the scene of a dinosaur chase - preserved in the mud of an ancient river bed in Texas.
The tracks were left by two dinosaurs more than 110 million years ago.
Seventy years ago, the whole trackaway was removed from the river bed and divided into blocks, which were moved to different locations for study.
Some of these blocks have been lost, but researchers have now used old photographs to reconstruct it.
Here, lead researcher Peter Falkingham from the Royal Veterinary College, London, explains what the digital model has revealed.
Footage courtesy of Peter Falkingham/RVC