 In March 2001, "Jurassic Park III" director Joe Johnston said he and executive producer Steven Spielberg had discussed a story idea for a fourth "Jurassic Park" film, which Johnston was not interested in directing.In May 2001, Spielberg had Amblin Entertainment commence development of ideas for "Jurassic Park IV", which he planned to produce.Late in "Jurassic Park III"s production, Spielberg devised a story idea he believed should have been used for the third film.