Warner Bros. and Unique Features are revving up development on “Alien Zoo,” tapping Brian Nathanson to rewrite the high-concept family comedy.The film, which will be live action with CGI, will be produced by Unique’s Bob Shaye, Michael Lynne and Dylan Sellers. “Alien Zoo,” based on an original idea by Sellers, combines “Jurassic Park” with aliens. Joe Stillman, whose credits include the first two “Shrek” films and “Percy Jackson and the Lightning Thief,” was signed last year to pen the first draft. Nathanson’s credits include “The Occasionally Interesting Anti-Adventures of an Unnamed Girl” for Disney and “The Many Deaths of Barnaby James” for Appian Way and Warners. He’s repped by CAA and Benderspink.