Trivia: When the Tyrannosaurus Rex walks past the circular shaped waterfall, it lines up perfectly recreating the Jurassic Park movie logo.
Trivia: The shaving cream can held by Dodgson is the very same one seen in Jurassic Park, used by Nedry.
Trivia: Bryce Dallas Howard has stated that the studio pressured her into losing weight for the first two films in the trilogy. When this third film came about, she fought back, and director Colin Trevorrow supported her. Since both Howard and Trevorrow have more clout now due to their success in Hollywood, the studio finally relented and Howard was able to make the movie with her natural body. She said this helped with her stunt work and performance, since she wasn't weak from forced weight loss.
Answer: The live dinosaurs are genetically tweaked recreations, they're not the "pure" dinosaurs of the past, which would still be of great interest. Plus just like any other archaeology or historical study, there's always more to be learned about the past, and a great many people are interested in what the past has to teach us.