The two-metre long femur, which weighs half a tonne, was found in 140 million-year-old former marshland now in the vineyards around Cognac.
The bone was discovered earlier in the week during excavations at the palaeontological site of Angeac-Charente near Châteauneuf-sur- Charente, southwestern France
The Angeac-Charente excavation site is unique in Europe and 7,500 bones belonging to 45 different dinosaur species have been found there since scientists first began excavating it in 2010.
The thigh bone is thought to have belonged to a sauropod, a herbivorous dinosaur believed to be the largest animal that ever walked the earth.
The femur weighs approximately 500 kilos
Jean-François Tournepiche, curator at the Angouleme Museum, said: “This femur is huge! And in an exceptional state of conservation. It’s very moving.”
The enormous bone probably belonged to a sauropod
Ronan Allain, paleontologist at the Natural History Museum in Paris, added: “We can see the insertions of muscles and tendons, scars.
“This is a very rare find as large pieces tend to collapse on themselves, to fragment.”
The enormous bone probably belonged to a sauropod
Over the last decade, scientists have managed to reconstitute more than 50 percent of a sauropod using several individuals discovered at Angeac.
