Marvel Studios kicked its marketing campaign for Ant-Man into gear today with the unveiling of Paul Rudd in costume as well as the first trailer for the film, but perhaps the biggest piece of news is the official Ant-Man script credits. You may remember that Edgar Wright initially developed Ant-Man over the course of several years to direct, writing the screenplay with Joe Cornish. He exited the project over creative differences last spring, but Marvel recovered quickly and had the film in front of cameras by late July with Peyton Reed in the director’s chair. Anchorman and Step Brothers writer/director Adam McKay was hired to do some rewrites on the screenplay, but since many of the action beats had already been planned out with Wright and Cornish’s script—and since there were only a few months between Wright’s departure and the start of filming with a new director—many were curious to see how much of Wright’s script would remain intact.

According to Disney’s press release for the new trailer, the official “screenplay by” credit goes to McKay and Paul Rudd, while Wright and Cornish get a “story by” credit and Wright remains credited as an executive producer. More after the jump.

Rudd told us back at Comic-Con that he and McKay had been working nearly every day for six weeks to rework the screenplay after Wright’s exit. After all, Wright and Cornish were penning the script that Wright was going to direct, and given that he’s a very specific (not to mention immensely talented) filmmaker, it would’ve been tough for any director to come in and execute that screenplay as-is.

In a subsequent interview with Collider, McKay elaborated on how much work he and Rudd did on the script, saying they added a “giant action sequence” and made the film “a little bigger, a little more aggressive, and funnier in places.” Indeed, it appears that McKay and Rudd’s work on the script was significant, as they appear to be ending up as the official screenwriters of this iteration of Ant-Man while the foundation of Wright and Cornish’s story remains.

That story was a pretty ingenious way of tackling the comic book adaptation. While it’s common in the world of comics for multiple characters to take up the titular superhero moniker, Wright and Cornish crafted an Ant-Man film that uses both of the main characters that filled the Ant-Man suit. Michael Douglas plays the superhero originator Hank Pym, while Rudd plays con man Scott Lang, who is taken under the older Pym’s wing and enlisted to wear the suit.

I’m interested to see if I’ll be able to spot Wright’s set pieces in the finished film (an Edgar Wright action sequence is pretty unmistakable), but it sounds like much of the dialogue and story structure may have been altered pretty significantly. I can’t say I didn’t finish the Ant-Man trailer still longing for Wright’s version of the film, but the screenplay credits suggest that this won’t be a Frankenstein’s monster version of Wright and Cornish’s script—this is Marvel’s Ant-Man as written by Rudd and McKay.