[thejohnconway]

Annoyingly, the wikipedia article was wrong, and mistakenly gave the figures for Quetzalcoatlus in that paragraph. Pteranodon weighed more like 20-30kg (I've edited it).

The constraint on the size of flying animals is launch, not flight. Pterosaurs could get bigger than birds because they used quadrupedal launch, meaning they could use their flight muscles during the initial leap.

[agentwiggles]

I never cease to be amazed how damn _big_ dinosaurs were. The size comparison on the page for Quetzalcoatlus is seriously mind boggling - the thing was almost the size of a small plane!