User blog comment:Kogath/Monster Hunter: World Discussion/@comment-25083735-20191105005322/@comment-25933225-20191107153600

I found some concept art that gives Lao full wings (look for «Lao Shan Lung concept art on  Google Image).

Tho it doesn't really prove anything, if we were to consider concept art then Lagiacrus is a fish because one of the concept arts depicts it as a big-muraine-like fish. I still think Lao having wings in the past as very unlikely considering its morphology, even if I don't totally wipe out this possibility.