Dinosaur fossil footprint. Fossil trace of a footprint left by a theropod dinosaur from the Late Jurassic (145 to 160 million years ago). This fossil is part of the Dinoplagne site in Plagne, in the Ain department of France. This is the longest set of dinosaur fossil tracks in the world, extending for 155 metres. The name Odysseus was given to the sauropod dinosaur leaving the tracks. It is thought it weighed 50 tons and was 30 metres in length, walking at about 1 kilometre per hour. The name Marcel was given to a theropod dinosaur that left this single footprint crossing the sauropod track. The tracks were discovered in April 2009. Photographed in July 2011.