The Origin of the Universe

Most of the scientists think that the Universe started from a "singularity" more than 15,000 million years ago, the starting point was so small that it can't be imagined. It contained all the elements of the Universe (matter, energy, time, and space) Once it made an explosion that it is very difficult to imagine.

The causes of the first explosion known as "Big Bang" are unknown to the scientists. It happened about 15,000 million years ago and they don't know if something existed before it, or even more, if there was a "before". It is thought that the" black holes" are like this "singularity", but they contain a tiny quantity of Universe.

It is also possible that the black holes could be formed by collapsed stars of such a density and gravitational force that absolutely nothing, even the light can escape from them. The scientists speculate that due to the "Big Bang" as an energy fire, the Universe is even in expansion.

The Origin of the Solar System

About 4,800 million years ago on the borders of our galaxy, the Milky Way (only one in 100,000 million), a cosmic powder cloud began to group into a turning disk attracted by its own gravitational force. As the disk was forming, the force of gravity compacted a great gas cloud in the center of the force, the hydrogen atoms began to fuse, causing a nuclear reaction that gave place to the Sun itself Nine new gas accumulations, turning round the sun became planets, one of them was the Earth. The nearest to the Sun, (Mercury, Venus, Earth, and Mars) became small rocky planets. The other ones (Jupiter, Saturn, Neptune and Uranus) were covered by big gas accumulations. When the Earth was formed, it was impossible to live on it. It was very hot, and it had no oxygen at all to allow life. A very long period of time was necessary for it to be prepared to house animals and plants.

The Origin of Life

Museo Argentino de Ciencias Naturales

The Earth is about 4,600 million years old. Along the first 1,000 million years the poisonous gases, coming from volcanoes and the lack of an atmosphere and of oceans didn't allow any kind of a life. By that time there was only one continental mass known as "Pangea".

After millions of years, the Earth surface got colder and solidified. When this fact happened very big quantities of poisonous gases and water vapor were expelled from the Earth heart creating the first atmosphere. Life was impossible there because there was no oxygen, there were volcanic eruptions and lava lakes later on, the water vapor began to condensate and it fell down as rain. Along millions of years it rained constantly on the planet, giving place to the seas and oceans.

3,500 million years ago, the first unicellular organisms without nucleus were originated. More complex ones appeared million of years later. The plants with several cells, and the animals originated 700 million years ago. Among those primitive organisms we can mention Braquiodopods, mollusks, Arthropods with external skeleton, corals, sea urchins and fishes. Later on, after an evolutionary and adaptation process, the sea species developed into river and lake ones. About 370 million years ago the amphibious ventured into the terrestrial life.

Geological Eras (click here to see chart)

All the changes produced in the planet (even the nowadays ones), the same as its ruling life, are marked by ages, (eras), periods and epochs. The Precambrian Period went along the first 4,000 million years, during the same the Fanerozoic Period that means "abundant life" went along the last 570 million years. The last one is divided into three ages the Paleozoic (from 570 to 245 million years), the Mesozoic (from 245 to 65 million years) and the Cenozoic that went along the last 65 million years.

Museo de Ciencias Naturales de La Plata

PALEOZOIC ERA

The seas belonging to the Devon period (408 to 360 million years) were inhabited by a lot of groups of invertebrates. The corals played a very important role as reef makers, but there were also some forms of solitary life. The Braquiodopods diversified themselves presenting a great variety of forms corresponding to different ways of life.

There were Gasteropods, Cephalopods, Nautiloideus and Amonoideus. Among the Equinoderms the best represented group were the Crinoideus. The Trilobites had diminished, and the Graptolites were declining.

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MESOZOIC ERA

The Mesozoic Era (Middle Life) also known as "Secondary Life" or the "Reptiles Era" lasted along 185 million years. It is divided into three periods: Triassic (between 245 and 208 million years), Jurassic (between 208 and 144 million years), and Cretaceous (between 144 to 65 million years).

Approximately 300 million years ago, the Gondwana super Continent, and the Northern Continents (Eurasia and North America) collapsed giving place to Pangea, a continental mass going from Pole to Pole, surrounded by the Pantalacic Ocean, at the same time the Tethys Ocean appeared. It was the Mediterranean Sea predecessor.

There was a sea level fall, and masses of land blocked the oceanic currents from north to south. The scientists say that this fact together with the meteorites impacts and the lava coming from Siberia could have caused, the biggest extinction phenomenon that happened on Earth, about 250 million years ago. The surviving reptiles colonized Pangea, giving place later on to the dinosaurs, among other animals.

Along the Mesozoic Era the drifting of the Continents could have evolved as follows:

a) In the Late Triassic (about 280 million years ago) Pangea began to be divided into three parts, Eurasia-North America, Africa-South America, and Antarctica-Australia-India. The Pacific Ocean, together with other seas that appeared by the time, allowed that the sea currents coming from Ecuador reached the poles causing like that better climatic conditions along the whole planet, which helped to the appearance of the dinosaurs life.

b) At the end of the Jurassic (about 144 million years) the Atlantic Ocean appeared. The Pacific Ocean became more defined, and the Tethys Ocean conformed a marine current of global character. As a result, several evolutionary isolated niches began to develop along the continents.

c) At the end of the Cretaceous (65 million years) the continents were approximately conformed as they are nowadays. In India there were a lot of volcanic eruptions. At the same time, at the Yucatán Peninsula in Mexico Gulf a comet could have impacted, leaving awful consequences to planetary level. There were a lot of storms, Tsunamis (giant sea waves), and forests and jungles fires. The volcanic and cosmic powder, in addition to the smoke, caused the Earth darkness and the dinosaurs and ammonites extinction.

"Bosques Jurásicos", by the artist Jorge Blanco - Museo Argentino de Ciencias Naturales

The dinosaurs appeared along the Late Triassic, reaching a great development during the Jurassic. When they disappeared the Cenozoic Era began. More than 65 million years were still missing for the first human beings appearance. 6,500 civilizations of 10,000 years each one must should happen to see the first biped, with human being appearance, walking erected by two feet through the prairies. Going on with this example, and regarding the Carl Sagan´s brilliant idea, if we would make the 15,000 million years from the Big Ban, equivalent to a 365 days year, our civilization of 10,000 years would represent no more than the last 20 seconds of the 11:59:40 p.m. on December 31st, of the hypothetic Cosmic Calendar. Christ's birth would have happened in the last 4 seconds! That is to say, that our wonderful civilization of about 10,000 years would be no more than ……"a moment at the night of times".

Click here to see December at the Cosmic Calendar

Click here to see 31th December at the Cosmic Calendar

The alive species in their evolutionary process, adapted themselves to the geographic and climatic changes. When there was only one continent, there were very big areas having a dry climate because there were neither oceanic winds, nor enough rain.

400 million years ago, the continents began to move, so big mountain ranges appeared. The seawaters left empty spaces, and the vegetables coming from the seaweeds began to adapt to the new environment, developing roots, stems and leaves. On the new watersides, a lot of insects, water species, and mites appeared.

300 million years ago, the reptiles grouped to the Arcosaurian, which adopted several forms, such as the terrestrial crocodiles, and the quadruped hunters. They were Tecodonts because each one of their teeth was inserted into a deep hole known as alveolus.

Under the Arcosaurus category were the animals that put all the sole foot on the ground when they walked About 240 million years later the first dinosaurs appeared. They had a very well marked difference between their front and back limbs. As time passed they afforded an evolutionary process, and they became the first reptiles that did not crawl. But when the continents got separated about 60 million years ago, the climatic conditions changed. During the Jurassic a lot of places were covered by seawater and the winds brought the winds to the regions. Along the Cretaceous, the continents and the climate were similar to the present ones.

According to the information of several sources, during the Triassic the different species changed in several ways: the Lesothosaurus became drowsy along the dry periods, other dinosaurs would have had quills through which the morning dew would descend to keep them cool.

Along the Cretaceous, when the vegetation became abundant, the long necked sauropods would be replaced by herbivorous dinosaurs.

During the last period of the dinosaurs life there was a lot of volcanic activity. The lava destroyed everything, and a poisonous gas cloud contributed to cause the massive death of animals and vegetables. At the same time that the dinosaurs began to extinguish the continents took their current disposition. Australia and the Antarctica separated from South America. India joined to Asia forming the Himalayan mountain range. North America, South America and Europe settled into their current positions. So, the animal and vegetable life began to develop in different ways.

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CENOZOIC ERA

Along the Tertiary the sea covered several regions of the Argentinean territory. About 50 to 20 million years ago, the "Patagoniense" Sea was full of a fauna completely different to the one of about 10 to 4 million years ago that characterized to the "Entreriense" Sea in the north of Argentina. Many of the species that inhabited those seas are still alive but others have been extinguished.

THEORIES ABOUT THE EXTINCTION OF THE DINOSAURS

There are different theories about it.

Fundación Epson Argentina

The big meteorite impact

This theory says that the dinosaurs' extinction was caused by the impact of a big meteorite on the Earth surface, that added to the volcanic eruptions would have caused powder clouds that avoided the sun light on Earth. An iridium layer can be watched on the rock stratum in which the dinosaurs disappeared. This would prove this theory because the meteorites contain this element. One of them of about 8 to 12 km diameter would have crashed against the Earth. Its crater has never been found, however some people say that it exists near Yucatán Peninsula in Mexico.

At present, some scientists from 6 countries would be preparing to look for it. The wave that could have caused such a meteorite if it would have fallen into the sea would have had hundreds of meters high. Surely, its impact would have caused the whole planet shaking. It is estimated that once, each 70 to 100 million years, there is a possibility that a big meteorite crashes against the Earth surface causing a planetary catastrophe, according to the astronomer Shoemaker.

Fundación Epson Argentina

To have an idea of the destructive power of these meteorites, we can mention that about 50,000 years ago an iron and nickel asteroid impacted against the Earth at a speed of 5 km/second in the Arizona Desert USA, leaving as a mark, a crater of about 1 km diameter (1,185 meters) and 170 meters depth. It released energy 1,000 times higher than the one of the nuclear bomb on Hiroshima in August 1945.

Climatic changes

It is another theory that says that the climatic changes were caused by the continents separation. As new mountain ranges appeared, the temperatures descended giving place to new plants species. As the dinosaurs had cold blood (this is been discussed nowadays, because some scientists say that they had hot blood.) they couldn't have stood the sudden climatic changes.

Glacier Era

This theory says that with the coming of the snow and the frozen of the river's water, it was impossible for the dinosaurs to live .The dry hot areas disappeared, so, it was impossible to emigrate, and they could have died due to starving and cold.

Something else about the dinosaurs

Up to now, more than 400 different species of dinosaurs are known. Its remains can be found in Mongolia, the African deserts, Canada, China, Australia, USA, and in South America. About 70 different species of dinosaurs have been found in Argentina. It is about 10% of the world's total amount.

They are called according to the discoverer's name, or to some special characteristic, or by the geographic location
As an example, "Carnotaurus Sastrei", was called like that, because of the Sastre family, Giganotosaurus "south giant" in Latin, Argentinosaurus Huinculensis because of Plaza Huincul. The end of the name is always a Greek or Latin word, the decision depends on the paleontologist.

It is estimated that a fossilization was produced each a thousand dinosaurs, according to the time it could exist a fossil each 10,000 ones. It is impossible to distinguish between males and females, though of course, they are different.

The Patagonikus were one of the quickest, they were 1.5 meters long and they could run about 60km/h. The carnivorous ones had fragile jaws and plain teeth similar to a knife. The jaws of the herbivorous were massive, with robust teeth and smooth edges. .

A lot of animals such as: turtles, crocodiles, small mammals, Pterosaurian, snakes, fishes, and insects, lived side by side with the dinosaurs. But we can say that their aspect was different than the nowadays ones.

They were affected by illnesses such as arthrosis or bone tumors, and some fossils had broken bones too. They also suffered from teeth infections. After their massive extinction, a carnivorous group survived, they became the current birds.

Other species such as the Therapsids, and the Cotilosaurus, reptiles of about 4 meters long, disappeared by the end of the Paleozoic Era.

The dinosaurs' color is unknown, since it would be determined by organic components that were lost during the fossilization process. It is believed the giant dinosaurs lived about a century, and the smaller ones about 15 years

National Law 9080

It says that the fossils remains found in Argentina can not be sold. The dinosaurs' bones sale is strictly forbidden. This law is regulated by the decree 1921.