Extinct dinosaurs

What really made the dinosaurs back back then make them extinct cause I'm starting not to believe that a comet killed them all. What did?

it wasnt a comet
it wasnt a flood
and it wasnt any god
scientists still dont know the exact answer to this question
so its impossible to give a correct answer
but one of the most proveable reasons why most of them died would be a change in temperature
this would have caused most of them to die, leaving a lot of carnivours with no food, so theyd die, and would make a lot of plants die, so the herbavours that were left would have died as well
but some of them like crocodiles did survive, and there still around today
some prehistoric animals and plants from the dinosaur age did survive and evolved a bit or a lot and we have them or there ancestors today
so whatever killed them didnt kill all of them

it was mainly an iceage, starvation, volcanos that erupted killing several species.

global warming has everything to do with the weather by the way

your right scientist don't know for sure, but most agree that a meteor was the 'trigger' for the end of the dinosaurs. Some people think that the dust and debris from it clouded the earth, killing most plants, that kills herbivores that kills carnivores. some think the dust and debris trapped gases and turned the earth to an oven.

There were other mass extinctions besides the one that killed the dinosaurs.

The Ordovician-Silurian extinction event - 440-450 million years ago, killed about 85% of all species

The Devonian extinction - 360-375 million years ago, about 70% of all species went extinct

The Permian-Triassic extinction - about 251 million years ago, about 96% of all marine species and 70% of land species went extinct

And of course the Cretaceous-Tertiary extinction - about 65 million years ago, about 75% of all species went extinct including the dinosaurs

Among a couple other extinction events: http://www.newworldencyclopedia.org/entry/Mass_extinction

Also here are some other examples of what may cause extinction events.

A comet is not what would have killed all dinosaurs but the effect an impact may have, the evidence for it is in the geologic record.

Impacts can be simulated, on much smaller scales of course, by scientists to get an idea of the effect that they may have.

Not to mention the direct observation we got from Jupiter's collision with comet fragments (travling at 60 km/s)
Jupiter's gravity caused the comet to break up into fragments up to about 2 km across and even still the collisions left explosions that were nearly the size of Earth (generally speaking)

The scars left by the impacts were easily visible and persisted for many months.