Those arms are looking pretty sweet. As for the legs, I'm not sure with the specifics, but from my work with dragons I could offer a few general suggestions. Honestly, the rear legs that you built on your dragons look like they would translate nicely into Dinosaurs with a little bit of re-proportioning.
I will be honest, I know NOTHING about building legs for dinosaurs. Or lizards. Or anything natural for that matter. If it was a Mech, then I would be able to help. But excellent work, this is amazing and so fluid!