You are thinking of diffrent things. The big bang was a giant explosion that allowed all the dust and debris from that to come together to form earth. Billions of years later was the dinosaurs thing
an asteroid hitting the earth, drought, volcanoes, disease, or rising sea levels
dinosaurs are extinct not endangered
About 65 million years ago a giant asteroid hit the Earth in today's Mexico. It caused many climate changes, which killed the dinosaurs.
Scientists usually refer to this as an asteroid, not a comet. It's the asteroid that caused the Chicxulub crater.
The dinosaurs all died out. A major catastrophe, probably an asteroid impact, caused their extinction.
A crater did not take out the dinosaurs..... But the crater caused by the asteroid that took out the dinosaurs is about 180 km (110 miles) in diameter.
mexaco
Dinosaurs became extinct 65 million years ago, at the end of the Cretaceous period.
Based on the popular theory that the dinosaurs went extinct due to the impact of a large asteroid, scientists think that the asteroid caused large amounts of debris to fly into the atmosphere, blocking out the sun. This caused global temperatures to drop, thus freezing the plants. In addition, without the sun the plants could not carry on photosynthesis, which caused them to die.
crocodiles lived because they lived in water and crocodiles had amour plates on it's back
There was an asteroid impact in the Yucatan Peninsula, about 65 million years ago, which caused global catastrophe for the existing species of the time.
About 65 million years ago was the Cretaceous-Paleongene excintion event, likely caused by a combination of an asteroid impact and a surge in volcanic activity. A number of groups of animals went extinct including ammonites, pterosaurs, plesiosaurs, and dinosaurs.