Dinosaurs first appeared during the Triassic Period, roughly 240–230 million years ago, with most sources clustering their emergence around about 230 million years ago.

Quick Scoop

When did dinosaurs first appear?

Most paleontologists agree that true dinosaurs evolved from earlier reptiles in the Middle to Late Triassic , after the massive Permian–Triassic extinction.

Key points:

  • Earliest definite dinosaurs come from rocks in Argentina and Brazil, dated to about 230 million years ago.
  • These early forms include small, lightly built species such as Eoraptor , a primitive meat‑eater whose skeleton suggests even older, as‑yet‑undiscovered dinosaur ancestors may have existed.
  • Broader geological and fossil evidence places the first dinosaurs sometime between about 243 and 233 million years ago, but 230 million years ago is a widely used benchmark.

In simple terms: dinosaurs show up in the fossil record around 230 million years ago, at the start of their long reign over the Mesozoic world.

TL;DR: Dinosaurs first appeared in the Triassic Period, roughly 230 million years ago, probably in what is now South America.

Information gathered from public forums or data available on the internet and portrayed here.