Everything Mesozoic is new again: Jurassic World, the hotly anticipated fourth instalment in the dinosaur-theme-park thriller franchise, has its first official trailer. Due for release on June 12, 2015, the Steven Spielberg-produced film, which has taken a circuitous route to the big screen, is the long-awaited follow-up to 2001’s Jurassic Park III. The film had originally…