Sprawling fantasy series getting film adaptation…. Deadline has learned that suits over at Warner Bros have scored the screen rights to American-Irish author Anne McCaffrey’s best-selling fantasy series ‘Dragonriders of Pern,’ with plans for a film franchise. The 22-book series, first published in 1968, is set in a pre-industrial society and focus on “an elite group of warriors who take to the skies on the backs of giant, fire-breathing dragons with telepathic powers. They try to save the exotic planet of Pern from a terrifying airborne menace — a rain of deadly spores that comes with the orbit of the Red Star.” Drew Crevello and Julia Spiro will oversee development for the studio. No screenwriter is currently attached.