The footprints measure up to 1.25m and date from the Jurassic period 168 to 166 million years ago. Some are very well preserved, showing marks of the fingers, foot pads and claws. This shape of footprints was previously unknown, so the scientists have named the dinosaurs Occitanopodus, after the region of Occitanie.
They walked on all-fours and were sauropods, similar to brontosaurus or diplodocus. They may have measured up to 30m long and weighed up to 50 tonnes.
Exploring their environment
The studies conducted in the cave 500m beneath the limestone plateau of the Causse Méjean in the Lozère show that the sauropods lived in a coastal environment and left their footprints on the edge of a lagoon, near a conifer forest. The prints have been left exposed after soft rocks beneath were hollowed out by acidic rains to form what is called a karstic cave.
Palaeontologist and Burgundy university lecturer Jean-David Moreau told Connexion: “Usually, we find dinosaur footprints of 20-30cm. From an international perspective, it is the first time that footprints of sauropods have been found in a natural cavity. And it is the first time we have discovered this type of footprint in Middle Jurassic deposits in France.”
The palaeontologists, from the Association Paléontologique des Hauts Plateaux du Languedoc (APHPL), have been studying the site with researchers from the Laboratoire Biogéosciences of Burgundy university since 2015. The Grands Causses region, where they were found, has yielded many dinosaur footprints over the last century.