The Mesozoic Island

In the '80s, a show about dinosaurs called: "The Mesozoic Island", was a hit and had as main characters four animals, Mr. Rex, a tyrannosaur, Bob a Triceratops, Susie, a pteranodon and Billy, a semiaquatic reptile.  Years later in 2005, Jeff is called by a major film production company to enter the old film set where the series was shot, to collect some pieces and relics of the series that were probably left there. He accepts the job and goes to the place where he discovers a horrible secret and has to survive murderous monsters.