The sick dinosaur Dr. Ellie Sattler examines in Jurassic Park is a Triceratops.
The scene occurs during the visitors’ tour of the island, when a Triceratops is found suffering from repeated bouts of illness. Ellie investigates its enclosure and examines dung samples while trying to determine what is making the animal sick. The moment demonstrates her expertise as a paleobotanist and advances the film’s wider theme that the park’s artificial ecosystem is not fully understood or controlled.
In the film, the characters suspect that the dinosaur may have been eating poisonous plants, including lilac berries. The sequence also includes the memorable detail that the animal becomes ill every six weeks. The Triceratops is a four-legged, three-horned herbivore, unlike the long-necked Brachiosaurus seen earlier or the armored Stegosaurus associated with later franchise appearances. The practical creature effects and close-up interaction make this one of the film’s most recognizable scientific investigation scenes.