“Dr. Alan Grant: [finding egg shells] Oh my God. Do you know what this is? This is a dinosaur egg. The dinosaurs are breeding. Tim: But Grandpa said all the dinosaurs were girls. Dr. Alan Grant: Amphibian DNA. Lex: What's that? Dr. Alan Grant: Well, on the tour, the film said they used frog DNA to fi…”
— Michael Crichton, David Koepp, Dr. Alan Grant, Sam Neill, imdb.com