Ordovician-silurian Extinction:

440 million years ago
Small marine organisms died out.

Devonian Extinction:

365 million years ago
Many tropical marine species went extinct.

Permian-triassic Extinction:

250 million years ago
The largest mass extinction event in Earth's history affected a range of species, including many vertebrates.

Triassic-jurassic Extinction:

210 million years ago
The extinction of other vertebrate species on land allowed dinosaurs to flourish.

Cretaceous-tertiary Extinction:

65 Million Years Ago
The extinction wiped out some 50 percent of plants and animals.

The set of geographical features that we can contemplate on the earth's surface, such as mountains, slopes, valleys and plateaus, constitute the relief
.
External geological agents can be passive or active:

Passives:

they produce the disintegration of the rock, but they do not mobilize these fragments. They are atmospheric agents: temperature, humidity, oxygen, etc.

Active:

capable of fragmenting a rock and mobilizing the fragments.
They are:

Water. It works in various ways:

Rain: it wears down the ground and tears off small fragments, which are washed away.
Surface continental waters that, in the form of torrents, rivers, etc. They act with different intensity.

The internal geological agents are the internal forces of the planet that cause the deformation of the earth's crust. The most important are:

Volcanoes:
Fissures in the earth's crust that reach deep areas, through which magma is expelled: a mixture of molten materials with variable amounts of water, gases and small solid fragments of rock.

Earthquakes or sixths :
they are sudden movements of the surface layers of the Earth, produced by the fracture and displacement of large rock masses inside the crust

A wide range of animals and plants suddenly became extinct, from small marine organisms to large dinosaurs.

Species go extinct all the time. Scientists estimate that at least 99.9 percent of all species of plants and animals that ever lived are now extinct. Therefore, the disappearance of dinosaurs around 65 million years ago would not be especially noteworthy, except for the fact that about 50 percent of all plants and animals live at the same time they also went extinct in what scientists call a mass. extinction

The word fossil comes from the Latin fossĭlis, which in turn derives from the verb fodere, which means 'to excavate'.

Fossils are generally found in sedimentary rocks. For a fossil to form, the organism must go through a physical-chemical process called fossilization. This process petrifies the organism after it is buried and conserves it for a long time in the earth's crust.

The importance of fossil findings and their study is that they serve to reconstruct the natural history of the world, collecting data and clues of the organisms that exist in remote times, such as the finding of dinosaur fossils.

Tectonic plates are fragments of the lithosphere, made up of the upper part of the upper mantle and the earth's crust, that behave as a strong, relatively cold and rigid layer. The lithospheric plates are thinnest in the oceans, where their thickness varies from a few kilometers in the mid-ocean ridges to 100 kilometers in the deep ocean basins.