It has been said that Wayne got him the "Gunsmoke role." That it was offered to Wayne, but he turned it down. I think I remember Arness having a part in Island in the Sky," a darn good Wayne flick.
Aye! ...You know John Wayne, never did, any SciFi films, just think about it...Christer Lee, Walter Pigeon, Bogey, Alec Guinness and many fine actors...Daffy Duck/Bugs did, too..."Put 'em up, or I'll vaporize ya'..ya' da@n Alien." :D