Sonidosaurus

Sonidosaurus is the only sauropod known from the Iren Dabasu Fauna, a group of dinosaurs that lived in the same area.1

Its fossils were found in the same quarry that later yielded the giant bird-like dinosaur Gigantoraptor.1

The hip bone (ilium) of Sonidosaurus had air spaces inside, a feature not common among non-avian dinosaurs.3

Scientists think Sonidosaurus was a mature adult when it died because the bones in its spine were fully fused.3

Sonidosaurus had a mix of old and new features, which makes it tricky for scientists to figure out exactly where it fits on the dinosaur family tree.1

It lived during the Campanian age of the Late Cretaceous, about 83 to 72 million years ago.2