The enormous femur was dug up in a fossil-rich area in Charente, and dates back 140 million years.
Sauropods are the largest herbivorous dinosaurs known to date — and include diplodocus, brachiosaurus and brontosaurus
They first appeared in the late Triassic Period, but this particular dino is from the Jurassic era.
It was discovered “nestled” in a thick layer of clay by volunteers from the National Museum of Natural History.
The bone itself weighs an incredible 500 kilograms (1,102 pounds) — just heavier than an average modern horse.
And it was discovered alongside a giant pelvis bone hidden within the same layer of clay.
Charente is best known for the town of Cognac — home to the brandy — but it’s also a hotbed for fossils.
Paleontologists have already uncovered around 7,500 bones from the site since 2010.
It’s estimated that these bones are linked to as мคหy as 45 different species of dinosaurs.
But the femur is the biggest bone uncovered from the site so far.
“This femur is huge! And in an exceptional state of conservation,” said Jean-François Tournepiche, Angouleme Museum curator, speaking to The Local.
“It’s very moving,” he added.
Experts believe that the femur likely belonged to a sauropod, which is one of the biggest dinosaurs ever to roam Earth.
Sauropods are identified by their long necks and plant-based diets.