Why certain dinosaurs survived ?

There are several theories but they all are common to one thing. A number of factors provoked alterations in the climate and in the nature.
But even today there are still no certainties.
Several theories that can explain it:

1 - one big meteorite collided with the planet earth that was able to provoke an immense cloud of dust. With no light from the sun the plants died and so animals.
This is the most common explanation and one that can determine why climate changed so radically.

2 - plate tectonic movements generated earthquakes, tsunamis and accelerated the activity of volcanoes during a long period. This also provokes clouds of smoke, toxic gas and formation of new territories and alteration of the nature.

3 - one of biblical inspiration tells of floods during a long period. They changed the nature scenery and the level of the oceans. It is credible that this it could have happened because alterations on the nature influence directly the climate.

4 - the theory of milankovitch wich explains that the axle of rotation of the planet earth suffers light diversions from 4000 to 4000 years, sufficient to provoke alterations in the climate due to the alteration of the angle of solar incidence and wich coincides to the periods of cooling or heating in the planet.

5 - the last factor that influenced the survival of some sorts of animals was ... luck. With the new scenery the animals have to choose new territories where foods were abounding. Some of them had been enclosed in a sterile and others have luck because they found good places.

All the alterations produced in the nature put on trial the capacity of adaptation of all animals. But why some species survived and others not? Those who had the capacity of dislocation for beyond the terrestrial mode managed to exceed this big obstacle, the others disappeared. Both the turtles and the crocodiles (with prehistoric origin) are animals well adapted to the land and water. And this was a trick for the survival of those species. Many animals were enclosed in islands and new territories, without any food and any capacity to move in the water or on air to found new territories with food. The crocodiles managed to adapt well to the new scenery, they developed a tail and a hybrid system of breathing. Also some insects and birds managed to survive because they can move on the air.

So those animals who had the capability to adapt to new situations managed to survive.
Some animals still today cover large distances like their ancestral predecessors from the times in which these alterations took place in planet earth like a memory that is in their genes and raisin from generation to generation.

The climatic alterations are originated by several natural factors and are succeeded in regular cycles by thousands of years. That proves the theory of Milankovitch cycles and it not seems to me that the alarmism on the " global warming" or in the "climatic changes" with human origin could be rational. It is completely ridiculous to affirm that CO2 is a public enemy or a toxic gas.