DreamWorks' Wild West adventure Cowboys & Aliens will have to find someone else to wield a six-shooter, because Robert Downey Jr. has dismounted from his horse. According to The LA Times, Downey Jr. has has to drop out of the DreamWorks film due to schedule conflicts.
While he hasn't officially signed onto anything, it's rumored to be a conflict with a Sherlock Holmes sequel. Or maybe he just needs a break -- I mean, two franchises plus The Avenger and its spin-offs? Maybe he drew the line at a third. Too bad. He looks so good in hats!

Cowboys & Aliens still boasts one half of the Iron Man duo, as Jon Favreau remains in the director's chair. The hunt is currently on the hunt for a manly actor who can replace Downey Jr. The film is a potential franchise for any one brave enough to grab the reins and play Zeke Jackson, leader of the anti-alien revolt. All those who failed to get in The Green Lantern or Thor might want to call up Favreau and DreamWorks, because once you're in a Favreau comic adaptation, you're untouchably awesome.

Production is tentatively set to begin this year for a release in summer 2011. In the meantime, you can still read Cowboys & Aliens online and cast your vote for Zeke Jackson in the comments. DreamWorks could use the help.