Between 230-65 Million Years ago, North America was a Dinosaur paradise, with no competition but themselves. They had it all. Little did they know, something soon was about to change that. A tragedy was about to occur that would alter the history for ever.
There were many kinds of Dinosaurs that lived on Earth. For example there were the T-rex, Triceratops, and the pterodactyl. The lived in a mostly hot and humid climate, and all over the world, mostly in North America though, as we have found fossils in these places.
About 65 Million years a meteorite struck the earth and killed the dinosaurs. After just hours after the meteorite stuck dinosaurs became extinct. This tragedy killed 80% of life at the time.
Some examples of Dinosaur fossils being found are in South Dakota Sue Hendrickson, found the largest T-Rex in 1990. Also in Colorado at the University the found a Dinosaur dung that was over 66 Million years old.
We know that the Dinosaurs went extinct because we found many Dinosaur fossil in sedimentary rock. The fossil record shows us that something tragic happened around 65 million years ago, because there were no Dinosaur fossils found in rock that was younger than that. Fossils were found all over mainly in North America.
Mammals survived this catastrophic event and soon began dominating planet earth. We also know that mammals started to evolve over time. We know this because the rock that is less than 65 million years old shows use that mammals started to take over after dinosaurs.