Spokeswoman Karla Arrollo says the 1.5-meter (5-foot), remote-controlled dinosaur worth $25,000 disappeared after Friday's performance. Police say they are investigating the alleged theft.
Arrollo says the show - which features 10 species of large, mechanized dinosaurs lumbering across an arena stage - will continue touring.
But organizers had to redesign the first scene, which originally involved a larger dinosaur devouring the baby.
She says organizers have also requested increased security to protect the prehistoric performers when the show opens in Mexico City on Wednesday.