1. Triassic Period (252-201 million years ago):

1. Dinosaurs first evolved from reptiles during the Triassic period when Earth’s landmass was one supercontinent, Pangaea. These early dinosaurs were generally small and bipedal, like Coelophysis.
2. Jurassic Period (201-145 million years ago):

1. During the Jurassic period, dinosaurs diversified and became the dominant land animals. As Pangaea split apart, new environments supported a wide range of species, including giant herbivores like Brachiosaurus and armored dinosaurs like Stegosaurus. 3.Cretaceous Period (145-66 million years ago):

1. The Cretaceous period saw the peak of dinosaur diversity with species like Tyrannosaurus rex, Triceratops, and Velociraptor. Flowering plants began to emerge, and the continents continued to drift into their modern positions. This period ended with one of the most significant mass extinction events in Earth’s history.
2. Extinction (66 million years ago):

1. The Cretaceous-Paleogene (K-Pg) extinction event was triggered by a combination of factors. A massive asteroid impact near modern-day Mexico caused global wildfires, tsunamis, and threw vast amounts of debris into the atmosphere, blocking sunlight and disrupting ecosystems. Additionally, volcanic eruptions in the Deccan Traps released gases that contributed to climate change. These events led to the extinction of 75% of Earth’s species, including all non-avian dinosaurs.
2. Survivors:

1. Birds, which evolved from small theropod dinosaurs, were among the few species to survive this mass extinction. These avian dinosaurs continue to live today, while the rest of the dinosaurs disappeared, giving rise to mammals as the dominant species.

This version offers a more detailed but still concise overview of dinosaur history, including their extinction.