What Caused the Demise of the Dinosaurs?

Do you know how long the dinosaurs live in this earth, well here that answer. The dinosaurs lived about one hundred million years ago they spread out because of the continent the time the continents were together. During that time the climate was warm, there wasn't broad-leave trees, no flower-bearing plants, no ice 

 polar, the moon was closer, the day was longer.

The Argentinosaurus were so enormous because they don't even have predators. and they had more mass and they don't need to run from their predators because of their giant height. The dinosaurs demise because of the mammals became bigger and more competitive, there was drifting, isolated continents touch 

each other, there was a new rival that appear,  there was new diseases spread for the bite of the other animals. Also the climate was getting colder.