For the past week, cast members of Marvel Studios' impending "Avengers: Age of Ultron" have unveiled solo character posters on their respective Twitter accounts. Tuesday morning saw Chris Evans debut a poster via tweet starring his character, Captain America.

And here's the rest of the posters released so far -- all six main cast Avengers are accounted for, along with Nick Fury, but any of Ultron (James Spader), Scarlet Witch (Elizabeth Olsen), Quicksilver (Aaron Taylor-Johnson), Vision (Paul Bettany) or Maria Hill (Cobie Smulders) could be next.

Written and directed by Joss Whedon, "Avengers: Age of Ultron" is scheduled for release on May 1.