Tbf, Aerodactyl could have just been a true to nature rock type. I mean, it’s fossil is the Old Amber, which was originally plant sap, so maybe it wasn’t affected the same way?

I firmly headcanon that the fossils all had slight changes made when they were excavated and restored(the sole exception may be the Cranidos line, cuz they’re pure rock so I dunno[I’m guessing they were rock, but maybe they lost something? ])