Although there's been a lot of speculation about who the villain might be in Joss Whedon's adaptation of The Avengers -- The Hulk? Loki? -- there's been very little indication who Earth's Mightiest Heroes will face in Marvel's 2012 tentpole. Until now, that is.

In its report about Marvel's decision to shoot the film in New Mexico, the state's largest newspaper, the Albuquerque Journal, reveals "The Avengers' script will blend Iron Man, Thor and Captain America: The First Avenger story lines as the Avengers battle with two alien races, the Skrulls and the Kree."AICN, which has a scan of the newspaper page -- the online version of the article is hidden behind the Journal's paywall -- notes there's no attribution for what amounts to a pretty big scoop. So there's always a chance the reporter relied on Internet scuttlebutt rather than information from official sources.

Whatever the case, a Kree-Skrull conflict certainly would make for an intriguing scenario on a grand, cosmic scale.

Most fans of superhero comics are at least somewhat familiar with the militaristic Kree and the shapefshifting Skrulls, two alien races whose histories are intertwined with the major players in the Marvel Universe. "The Kree-Skrull War," a storyline that ran through The Avengers from June 1971 to March 1972, detailed the heroes' efforts to defend the Earth against the intergalactic conflict.

As Screen Rant points out, the Kree-Skrull rumors are nothing new, dating back to at least Comic-Con International 2009, when the shapeshifters were first mentioned as potential villains for The Avengers. They were bolstered in May by reports that Kevin Pennington, a young actor who's been mentioned in connection with numerous Marvel roles -- among them, Captain Marvel/Mar-Vell, a key character in "The Kree-Skrull War" -- had signed a three-picture deal with the studio.

The Skrulls and the Kree have been featured prominently in such recent Marvel comics crossovers as "Secret Invasion" and "War of Kings." The Skrulls also were reimagined in the publisher's Ultimate line as the Chitauri, alien shapeshifters who financed the Nazis in an attempt to conquer Earth. They were eventually defeated by the Ultimates.

In related news, a rumor that sprang up last week that Firefly's Alan Tudyk will play Ant-Man in The Avengers and in Edgar Wright's long-gestating Ant-Man appears to be false. "News to me," the writer-director tells Cinematical.

The Avengers, which stars Robert Downey Jr., Chris Evans, Chris Hemsworth, Mark Ruffalo, Scarlett Johansson, Jeremy Renner, Samuel L. Jackson, Don Cheadle and Clark Gregg, begins filming in April. It opens on May 4, 2012.