Palaeontologists from Beijing, Bristol and Bonn discovered the distinctions in arm or leg growth through a combination of biomechanical research and bone histology. known as the ‘parrot dinosaur’ – lived through a massive growth spurt in their legs, while the advancement of their arms slowed.
Resources:
http://www.telegraph.co.uk/science/dinosaurs/10147794/Dinosaurs-crawled-like-toddlers.html