Just found out how the fossils work.

Anyone willing to trade me the drake fossil with me? In turn, I'll give you the sword exclusive bird fossil for it.

Also is there anyway to know if your trading partner's pokemon is holding the fossil? I don't wanna get fucked.

To clarify.

1 bird fossil for your drake fossil

Unless by any chance you don't want my bird fossil but still want to give a drake fossil

My code is 0408 and my trainer's name is Nathan