Dinosaurs lived on Earth for over 160 million years.
They appeared about 240 million years ago and became extinct about 66 million years ago.
This time is called Mesozoic Era and began about 250 million years ago and ended 65 million years ago. It’s also called the “Era of reptiles” or the “Age of dinosaurs.”
If you’re wondering why the Mesozoic Era lasted longer than the dinosaurs, keep in mind that it took millions of years until the first dinosaurs appeared.
The Mesozoic Era was a time between two extinction events. The first happened about 252 million years ago and wiped out half of all species, including most plants. But, of course, dinosaurs didn’t exist back then.
They evolved a few million years later from reptiles who survived the extinction event.
Dinosaurs evolved from reptiles who survived an extinction event
Lagerpeton is the name of a reptile with dinosaur-like characteristics and lived 236–234 million years ago. It could walk on two legs (this is called bipedal) and had a size of 25 – 70 cm (10 – 27.5 inches).
Not much is known about Lagerpeon because even if fossils exist, they are found in bad conditions. However, it’s thought to be one of the first dinosaurs, even if these reptiles are not classified as dinosaurs.
Dinosaurs lived during three periods: Triassic, Jurassic, and Cretaceous.
The Mesozoic Era, the era of dinosaurs, had 3 different periods and ended about 66 million years with a bang – when an asteroid hit the Earth once again and wiped out all nonavian dinosaurs and most other species.
Each period lasted about 50-60 million years.
- The Triassic period began 250 million years ago and ended 200 million years ago.
- The Jurassic period began 200 million years ago and ended 145 million years ago.
- The Cretaceous period began 145 million years ago and ended about 66 million years ago.
Not all dinosaurs existed during the same period. For example, the Jurassic period gained fame because of the movie “Jurassic Park” during the 90s, but most of the dinosaurs shown in the film weren’t from the Jurassic period.
Tyrannosaurus Rex, Triceratops, and Velociraptor lived during the Late Cretaceous period.
Brachiosaurus (giant dinosaurs with long necks), Dilophosaurus, and Stegosaurus lived during the Jurassic period.
All dinosaurs became extinct 66 million years ago. The extinction had an impact on other species, such as ammonites and large marine reptiles as well.
Before the Mesozoic Era, there was a period called the Paleozoic Era, which lasted from about 570 million years ago until 240 million years ago. During this period, fish evolved into early amphibians who could live on land and dominate the world. The Paleozoic Era ended with a mass extinction about 252 million years ago. A meteorite impact is thought to have caused this event, but it’s unclear what happened exactly.
During the Paleozoic Era, there were no dinosaurs or other groups of reptiles like crocodiles and lizards.
The first mammals evolved during the Triassic period. The most famous fossils from this period are the first dinosaur fossils.
The bones of the first dinosaurs were found in England and Germany, but they weren’t recognized as such at that time. They were discovered during coal mining operations and thought to be large bones of extinct elephants or other mammals.
Long story short:
Dinosaurs lived on Earth for over 160 million years, during which they evolved into many different species and came in all shapes and sizes. They first appeared about 240 million years ago, became extinct around 66 million years ago, and modern humans did not appear until only 200,000 years ago.