Millions of years ago, dinosaurs walked on loose soil in the Jura. At that time, the climate was humid subtropical. A bit like the one in the Bahamas today.
The Jura was bathed in a warm, shallow sea, with lagoons …
The traces of dinosaurs on the shores then dried up due to the strong sunshine, and solidified. Then they were covered by fine sediments brought in by the sea. Which turned into limestone over time.
This is what allowed the astonishing conservation of these prehistoric footprints, on two sites of the Jura: Loulle and Coisia.
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Among the greatest animals on earth
Loulle’s 1,500 footprints were discovered by chance in 2004. The site was then the subject of major paleontological excavations.
This research revealed the passage of several species of dinosaurs, over a period of several thousand years.
In particular, sauropods, vegetarian dinosaurs, among the largest animals that the earth has known.
The size of their prints testifies to this: 90 cm to 1 m in diameter for the rear legs. The front legs are crescent-shaped or half-moon shaped.
According to scientists’ calculations, these dinosaurs were 25 m long. And weighed between 20 and 30 tons!
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Color traces
Traces of theropods can also be observed in Loulle. Carnivorous dinosaurs walking on their hind legs.
Who left footprints similar to those of birds. In much bigger! With three fingers, the middle finger of which is longer than the others.
The Loulle site has been designed so as not to degrade these fragile footprints. A footbridge allows you to get as close as possible to them, without trampling them. Some of the traces have been colored, to better identify them on the ground.
But be careful, it is forbidden to leave the path and walk in the footsteps of the dinosaurs.
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Dinosaurs were not mountaineers!
A little further south of the department, in Coisia, the dinosaurs also wandered near the sea. And left traces in the mud, which has become limestone.
But the originality of the site is that the footprints are now visible on an almost vertical slab! And yet, “the dinosaurs were not mountaineers!”, As the explanatory panel specifies.
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Amazement and emotion
In fact, the rock was horizontal at the start. Before undergoing a folding which raised the layers on which the dinosaurs walked. This folding, due to the collision of the African and Eurasian continental plates, helped to form the Jura massif.
And there again, amazement and emotion win over the visitor. How to realize that these clearly visible traces were left by prehistoric animals! Dizzying!
These two open-air sites are freely accessible all year round.
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