This… is the most confusing message I’ve ever gotten but I’ll try to answer it to the best of my ability…? I know it’s related to this post but I don’t know why you’re asking me about jaw bones specifically and why they would grow legs… anyhow –

I think generally speaking, many animals that have a jaw bone would also be able to grow legs or something that closely resembles legs. If you count fins and other appendages, sure, then jaws would definitely grow legs, I don’t know why that makes me a dumbass though. I’m not a zoologist so I’m unsure about certain invertebrates like worms that might (??) have jaws or jaw-like mouth areas but definitely no legs… 

So bottom line – yes, “jaws might grow legs in certain cases” – did… did that help?