Dinosaur extinction is also known as the Cretaceous-Paleogene extinction event. Until now, the extinction of these species still comes as a mystery to scientists. However, most hypothesis point to climate change as being the dominant explanation. Remember that during these times the earth is still not that habitable for species to survive. Coupled with volcanic eruptions, and asteroid and meteorite bombardment, the atmosphere becomes occupied with various greenhouse gases intoxicating not only dinosaurs but all other species on earth. Plants, which are the major source of food, wilted and died, especially those that were not able to adapt to the extreme conditions. Those that were able to evolve or mutate may perhaps had significant decline in productivity. When the food chain collapse, it's effect accumulates from the primary up to the apex consumer. Thus, food shortage amongst species also become apparent.