What was the largest flying dinosaur?

Of all pterosaurs, the flying reptiles that lived alongside the dinosaurs, the giant Quetzalcoatlus is the largest – in fact it is the largest known flying animal of all time. With a wingspan of up to 15m and a head the size of a car, the Quetzalcoatlus ruled the sky in the Late Cretaceous period (100 to 65 million years ago). It is widely believed that Quetzalcoatlus fed on living dinosaurs, unlike other pterosaurs who preferred fish and dead animals, to fuel its enormous metabolic needs. Despite its incredible size this giant reptile weighed no more than 250 kilograms (550 pounds) due to the hollow bones associated with pterosaurs. The wing of the pterosaur was unique, a large membrane suspended from a hugely expanded fourth finger. Pterosaurs are largely regarded as the first vertebrates to achieve sustainable powered flight, although the largest relied mainly on the wind and gliding to stay in the air.
But can we call pterosaurs flying dinosaurs? There is much contention among palaeontologists as to whether these flying reptiles should be classed as dinosaurs, but the physical similarities are plain to see nonetheless even if they don’t quite fall into the same category.