Crisis

Industrial Technological Center school and service number 103
"Francisco Javier Mina"

Students
* Luis Eduardo Santes Ortiz
* Nohemi Cruz Juarez

Subject
* English

Teacher:
* Cristina Sandoval

Name of theme:
Third unit project: Dinosaurs: What if ...?

1) Research about 2 most accepted theories about why dinosaurs became extinct

CRISIS FINICRETÁCICA
One ofthe most admitted reasons of this extinction is the impact of a meteorite in the peninsula of Yucatan (Mexico). It does approximately 65 million years, an object of approximately ten kilometres clashed with the coast of the Gulf of Mexico producing a crater that, initially, had between 80-100 kilometres of diameter and from 20 to 40 kilometres of depth.
To a speed of up to 250.000 kilometres perhour, it crossed the atmosphere in a few seconds, generating an earthquake of magnitude 13, one 'tsunami' with waves of up to 90 meters of height and injecting to the atmosphere and to the stratosphere approximately 21.000 cubic kilometres of powder and rock fragments.
When the solid incandescent matter came back to the surface it provoked serious fires. The accumulated powder prevented thearrival of the solar radiation for months, with serious consequences for plants and animals.
The crisis finicretácica supposed the extinction of numerous organisms, both in the terrestrial ecosystems and in the aquatic ones. Nevertheless, not all the dinosaurs went out. The birds, a specialized group provided with wings and pens, they survived the crisis, coming to the present day.
The extinctionsin mass take place as relatively rapid phenomena to the scale of the geological times, which imply the disappearance of a high percentage of species. The fossil record indicates us that diverse extinctions have existed in mass during the last 500 million years of the history of the life.

CLIMATIC CHANGE
A radical climate change does 70 million years can help to explain the changes lived inorder the Cretaceous one and the disappearance of the big dinosaurs, as they seem to reveal a few fossil remains found in the Peruvian Amazonía.
" With this discovery we show what the scientists were coming some time ago proposing, that it was not the meteorite of Yucatan what it extinguished to the species, but the extinction had begun before ", I explain to Efe the director of the PaleontologicalMuseum Meyer-Hönninger de Chiclayo (north of Peru), Klaus Hönninger.
Hönninger refers to the finding of a few fossils found in strata of several rivers of the Peruvian Amazonía, an environment that in the last times it reveals animal, botanical, archaeological secrets and now paleontological.
For precaution, the scientist refuses to reveal the exact location of these studied strata and limitsitself to saying that they are in the basins of the Ucayali and the Huallaga, since it wants to avoid the opportunists' appearance and predators.
The theory most accepted to explain the great extinction of the Cretaceous one was up to the moment the offer for the prize Nobel prize Luis Álvarez, who was defending that the impact does 65 million years of a meteorite in Yucatan (Mexico) provoked theextinction of good part of the fauna and flora that was living the planet and that supposes the step of the age of the big saurios to that of the mammals.
Nevertheless, and as Hönninger indicated, this theory has a weak point: how it explains that before a catastrophe of this type some species should survive while others did they go out?

2) Which theory do you think is the most likely?Explain why in your opinion
I think ..
In the personal thing I believe that both it has something of certainly. Nevertheless, I believe that the most probable was that of the crisis finicretácica, since the meteorite is a logical explanation for the extinction of the dinosaurs, and suppose that the tortoises and crocodiles could survive this event for his shell and his thick skin, this should...