Accepting the award, director and co-writer Inarritu said, "The journey of 'Birdman' started three years ago when I asked Nico, Armando and Alexander to follow me in a crazy idea, and because they are crazy, they did it and we wrote together 'Birdman.' For that, I am … grateful and thankful."
Inarritu also gave kudos to his cast, including
FULL COVERAGE: Oscars 2015
The win represents the first Oscar for each of the four writers, and the first nomination for Giacobone, Dinelaris and Bo. Inarritu had Oscar nominations in two previous years and is also up for director and best picture for "Birdman."
In the original screenplay category, the quartet beat out Wes Anderson for "The Grand Budapest Hotel," Richard Linklater for "Boyhood"; E. Max Frye and
Inarritu's fifth feature film, "Birdman" stars Michael Keaton as a past-his-prime actor grappling with ego and self-doubt while trying to regain his mojo by mounting a Broadway play.
Speaking to The Times when Oscar nominations were announced in January, Giacobone said the film's creative challenges brought out the best in the foursome.
"I think that for a writer, facing a huge question mark all the time — not knowing what that is and trying to learn what that is and trying to learn how to make it — it's very useful," he said. "It's how special things happen at the end."