Chapter 1: About Dinosaurs
Many many years ago there were many Dinosaurs were present in the world. Dinosaurs are land dwelling reptiles that lives million of years ago all over the world. They ranged in size and shape from as small as a chicken to larger than as an aeroplane. They had a larger variety of physical features of wings , plates , horns , spikes , scales . Some variety of dinosaurs: Aardonyx, Abelisauras ,Achillobator
Achelosauras , Acrocanthosauras , etc.
There were some Dinosaurs who were hunting other dinosaurs for their food and some dinosaurs who was eating leaves of trees , grass , bushes , etc.
In earlier some dinosaurs were chasing other dinosaurs for their food. In the chase some dinosaurs were fell from the mountains and died .
Dinosaurs were first appeared during the Triassic period , between the 243 and 233.23 millions ago , although the exact origin and timing of the evolution of dinosaurs is the subject of active reach .
They became the dominant terrestrial vertibrates after the Triassic Jurassic extinction event 201.3 million years ago ; their dominance continued through out the Jurassic and Cretaceous periods. The fossil record demonstrates that birds are modern feathered dinosaurs, having evolved from earlier theropods during the Late Jurassic epoch.
As such, birds were the only dinosaur lineage to survive the Cretaceous Paleogne extinction event approximately 66 million years ago. Dinosaurs can therefore be divided into avian dinosaurs, or birds; and non-avian dinosaurs, which are all dinosaurs other than birds.
The Cretaceous - Territory extinction event, or the K-T event, is the name given to the die - off of the dinosaurs and other species that took place some 65.5 million years ago . For many years, paleontologist believed this event was caused by climate and geological changes that interrupted the dinosaurs' food supply.
However, in the 1980s' father-and-son scientists Luis (1911-88) and Walter Alvarez (1940-) discovered in the geological record a distinct layer of iridium - an element found in abundance only in space - that corresponds to the precise time the dinosaurs died.
This suggests that a comet, asteroid or meteor impact event may have caused the extinction of the dinosaurs. In 1990s, scientists located the massive Chicxulub Crater at the tip of Mexico's Yucatan Peninsula, which dates to the period in question.
Thanks for reading..