about 450 million years ago

450 million years ago

Cladoselache

Other than birds, however, there is no scientific evidence that any dinosaurs, such as Tyrannosaurus, Velociraptor, Apatosaurus, Stegosaurus, or Triceratops, are still alive. These, and all other non-avian dinosaurs became extinct at least 65 million years ago at the end of the Cretaceous Period.

Dinos on the move The researchers looked at what happened when Pangea (sometimes spelled Pangaea) broke up into smaller continents in the Triassic period, which is when dinosaurs first evolved. In other words, dinosaur families cropped up on continents even when they were completely separate from their original areas.

No! After the dinosaurs died out, nearly 65 million years passed before people appeared on Earth. However, small mammals (including shrew-sized primates) were alive at the time of the dinosaurs.

They had hollow bones, didn’t chew their food, they had incredibly long necks, and likely possessed huge stomachs. These traits are theorized to be key in how they attained their enormous size.

The Dinosaurs’ Changing World The Earth had heavy vegetation near costs, lakes, and rivers, but desert in its interior. During the Jurassic Period, the continents gradually broke apart. The world was warm, moist, and full of green plants. During the Cretaceous Period, most of the continents had separated.

First Dinosaurs. Approximately 230 million years ago, during the Triassic Period, the dinosaurs appeared, evolved from the reptiles. Plateosaurus was one of the first large plant-eating dinosaurs, a relative of the much larger sauropods.

Dinosaurs (TV series)