> No, pterosaurs had wings built out of hand bones, and hands develop their size early in vertebrates. Therefore if you've got the right proportions to fly as a

> No, pterosaurs had wings built out of hand bones, and hands develop their size early in vertebrates. Therefore if you've got the right proportions to fly as a grownup, you should be able to as a kid. Whether that was right to birth is still debated, but certainly they could fly from being young. You've got the GP's question exactly backwards - they aren't questioning whether the juveniles could fly, only the adults. If you develop the full hand size early in life, and that supports flying with 20kg of mass, a 15kg juvenile is going to have a much better time of things than a 50kg adult. (Numbers pulled out of my ass, I'm not sure what the actual ones would be)