MacFarlane, creator of TV's "Family Guy," is to serve as host of the Feb. 24 Oscars ceremony honoring the best in film for 2012.
Thursday will mark the first time since Charlton Heston did it in 1972 that an Oscar show host has participated in the nominations announcement.
Stone starred in the 2011 Best Picture nominee "The Help" and the summer blockbuster "The Amazing Spider-Man." Her other film credits include "Superbad," "Zombieland," "Easy A," "Crazy, Stupid, Love" and "Gangster Squad."
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