Did all dinosaurs lay eggs?

All dinosaurs laid eggs, which were fertilized through sexual reproduction between a male and a female. There is evidence that some species of dinosaurs cared for their young during incubation and after hatching.

Scientists have long asserted that dinosaurs are the ancestors of modern birds, and like modern birds, female dinosaurs laid eggs after mating with a male. Following incubation, during which time the eggs may or may not have received direct parental care through body warmth and protection, scientists have found evidence that – depending on the species – the hatchlings could either remain with the parents or leave the nest to fend for themselves.