The Earth was formed according to many researchers and scientists for about 15 billion years ago by "the big bang" before the cosmos was basically nothing except a large dense matter clump, when "the big bang" came so formed the huge hydrogen clouds that were thrown out in different directions and the cosmos began to utvidagas with a speed of 500 km / s, the universe and all planets, galaxies, solar systems and stars had begun to form and one of the planets that would be formed called Earth.
Earth and primeval times (Precambrian)
Earth is about 4.7 billion years old, it is located at an ideal distance from the sun that makes it never gets too hot and never too cold, except at the poles that are never entirely directed towards the sun. Just when the earth was formed, it was omöljigt for life to begin, the earth had neither sunlight or oxygen. Volcanoes on the Earth's crust spat out vast amounts of hydrogen sulfide, koldoioxid and especially water vapor that came down just as quickly as it came up because it rained and thundered it very much in the earth's beginning. But after a while made it possible for life on earth it was begun combined together various topics nucleic acids, proteins and carbohydrates thanks to the emergence of new combinations of molecules. They first organisms that formed lacked cell wall and got their energy by chemical means through so-called Chemosynthesis. For about 4 billion years ago began the volcanic eruptions and the rain decrease and therefore gave sunbeams chance to reach Earth. Some who could utilize it where they live cells in the water as they became the first cells with korofyll and could utnttja solar energy in photosynthesis. Through their photosynthesis now had the earth been able to be more free oxygen, but it would still take about 3.4 billion years before any animals arose.
One can say that the earth's development is divided into four eras, prehistoric, ancient, medieval and present. I will now tell you a little about the ages antiquity onwards and explain a bit what animals and plants arising under them.
Forntiden lasted between 600- 225 million years ago, that was when they most species began to unfold. Forntiden is divided into 6 smaller ages and it begins with the earliest era called Cambrian started at 600 million years ago and hears at 500 million years ago, the other five ages called the Ordovician, Silurian, Devon, Krabon and Perm.
Cambrian 600- 500 million years ago
The biggest event in the Cambrian is that life in the water began in earnest, the marine wildlife not only increased but vareleserna started getting skeleton also which was not possible because there was almost no oxygen in the air. Now that they had received the bone then it was possible for them to leave fossil remains and the researchers have analyzed and researched further, but did not come up with any logical solution why the animals suddenly began to produce hard parts, ie the skeleton. This remarkable event is called the "Cambrian explosion". But how could the wildlife in the water start? In the beginning (primeval) so the air was completely oxygen-free but it has slowly risen to them 21% which we are accustomed, and the air has become more and more pure from large volcanic clouds and sunlight have found their way to Earth. When the sunlight came algae began to develop in grunadare water and animals that previously were fueled by synthetic means began to adapt and develop into algae eaters. And when the oxygen is increased to its normal level so the animals could develop a skeleton and become seafood eg trilobites that you have found some fossils from. A brief summary of the Cambrian period could be that the earth has developed oxygen and let in sunlight so they marine animals can develop and get a skeleton, than no animals on land.
Ordovician 500- 440 million years ago
During the Cambrian so formed vast oceans and there was not as much land to live on, but during the Ordovician so drew large amounts of water back and large amounts of the continents became the country. But during the mid-Ordovician so would a new transgression start, the water stigde again and it became smaller country, yet more land than at the beginning of the Ordovician. The large country change provided the foundation for the life that formed in the mid-Silurian time, but in the Ordovician, it's still just the water that goes to live in. Scientists have found fossils from the Ordovician period and they show that the species that lived then was mainly developed invertebrate fish eg bryozoder, echinoider, gastropods, and trilobites which is the animal that you found most fossils from. During this time, it had Still felt not developed any plants or animals on land so therefore they were marine animals in high need of new algae and other food because developed algae and and made it possible for animals to live under the surface for a few more 100 millions of years. The biggest event during the Ordovician was to fish occurred and that the water decreased so that fishermen can later develop their fins to feet and breathing through the mouth instead of gills and then also able to start a life above the surface.
Silurian 440- 395 million years ago
During the late Ordovician became began the third Ice Age and it will keep itself well into the Silurian. Since large parts of the country lay in the ice so was the development of plants difficult and the waters subsided and the larger wave of transgression was over, a time that was not enough water on earth. But the vast continental drifter as the water began to rise samtididgt as the ice slowly but surely began to melt, and the earth would again have its normal water level. When the water is re stigde and mighty rivers were created so they started earlier fishermen to develop some species of freshwater fish could live in the water's edge near land, the most famous freshwater fish that scientists know where Jaymoytius developed sometime around 400 million years ago. While the fish began to evolve into land animals began nature to get started with a few primitive plants that appeared in the late Silurian time, one of them these plants were Cooksonia, it is a plant that resembles cactus and who managed the climate on Earth during Silur time. One can say that the most important events of the Silurian time was that the ice smällte away and gave the fish and the plants chance to develop a little further into the country and not just looking the ocean.
Devon 395- 345 million years ago
Devon, or fishermen and ferns time is perhaps the time when life evolved the most. Freshwater fish began to evolve into amphibians, amphibians, or that scientists would say, and amphibians utveclades right on that front fins were feet and gills became the country adapted breathing. but they were Still felt very dependent on the sea and ate almost the only algae, one of the first amphibians evolved was Ichtyostega, it had fish body with feet and breathed through his mouth. It is not without reason they call Devon time of ferns time, the plants evolved quite significantly during that time and it was mainly ferns to come forward. Vascular plants began began to colonize large areas of land, they first plants that arrived were leaves and uprooted plants later in Devon time would evolve into ferns and Clubmoss which in turn would begin to create them first forests. But it was not only on land development went ahead during the Devon period but also in the sea where freshwater fish are developed at an enormous speed from being chinless creatures that swam around on the ground and ate algae to fish with jaws eg sharks and bony fish to less eg Dinichtys which was the first shark was developed. Grapotoliterna could not handle change but died out while the sea began to create the first few coral reefs through spongy stromatoporoideerna. During the Devonian period also began the giant sea gränlsade between Europe and North America to disappear, and when they both continents collided so had the Pangea supercontinent began to form.
Carbon 345- 280 million years ago
During the mid-Carboniferous then came the fourth glaciation in Earth's existence, and almost the entire half of the southern soil half lay in the ice while the northern half, which consisted mainly of Europe and North America had a behaglit climate that resulted in sea level height and formed large amounts of gundhav along the coasts. It made so that large marshes formed along the coasts, they were then quickly kolloniserade of them tropical forests which have actually had established themselves on the earth. When the swamps were taken over by the forests so formed huge stock of peat which is then buried beneath the forest and would eventually become carbon. It was formed vast amounts of coal and it is mainly why it is called Carboniferous, several large coal mines are left then Krabon time and they will probably last a good while before they run out. During the Carboniferous so they started the first insects to evolve in huge forests, it was mainly spiders and dragonflies that came and they were bigger than insects today, a mayfly could for example have a wingspan of 75 cm. Amphibians began more and more to develop into reptiles and reptiles larger plants jättelummer and giant horsetail began to grow in the forests so that it began to resemble a real tropical forest. Some amphibians developed in the late Carbon time is Hylonornus and Eryops. During the late Carboniferous so smällte the fourth Ice Age removed and giant continent Gondwana (Gondwana consisted of South America, Africa, Australia, Antarctica and India) began to slowly move up towards the ruling northern parts of the world to finally form Pangea.
Perm 280- 225 million years ago
During the latter part of the Perm time it was only China and some small islands which had not acceded to the giant continent Pangea. When Pangaea was formed as raised topography with few meters of the composite crust over the continent continued to press during off even though you did not get anybody anywhere, it was also due to the water dropped because they middle oceanic ridges pressed down by the huge land mass, so Pangea was formed not without consequences. Many organisms living in them warm shallow seas died out when flood waters receded, but it gave them great forests a perfect opportunity to expand even more. A small portion of the ice age, which was formed during the Carboniferous period remained at Gondwana when they collided with Europe and North America, but it ended pretty fast when it came to the warmer climate in the north. Pangea had a landmass that stretched almost from the south pole to the north pole. One time in Perm time so began the reptilians have dominance over the amphibians on land, reptiles began to take over the country were descendants of amphibians and had their weaknesses, but at the end of Perm began reptiles to evolve into mammals reptiles that became dominant over the amphibians and Also they last reptiles, an example of a reptile that developed in the late Perm is Dimetrodon. In the forest it began also to develop more and more, from Perm time so take the first conifer up in the forests and multiply very quickly. There will also be a fröormbunke and ormbunksväxterna becoming more common across the continent. In the sea developed not so much more than fish and bendjuren gets bigger and all other carnivores show up in the waters. A anna very important thing that happened was that almost 30% of all plant and animal families died out at the end of Perm time, especially hard hit was the judgment of marine families who suffered because of them powerful water elevation differences. But how plants and animals on land died out is one thing that puzzles and surprises many, actually there is no logical explanation but most believe it is the merger of Pangea to do, that something happened then that no one can really explain.
The Middle Ages (Mesozoic)
so ... there was some facts about the past and what has happened over 400 millions years of development. I will soon initiate the writing of the Third Age, the Middle Ages. The Middle Ages lasted between the years 225-65 million years ago and if I get to choose what age that is most interesting as it will without hesitation Middle Ages. The Middle Ages is divided into three smaller ages, Triassic, Jurassic and Cretaceous.
Trias 225- 200 million years ago
Along with Jurassic and Cretaceous so called middle ages for the big reptilian age and it was precisely what it was, in the early Triassic so, the procedure reptiles that ruled and there had been no new species of insects such as grasshoppers.
Dinosaurs would only come a time into the Triassic and take over but so far it was they who had less control.
They first true mammals began to come in the middle of the Triassic in the form of small mouse-like animals that had evolved from mammals reptiles.
The first reptile that looked like a crocodile had also arrived, it was called Rutiodon.
It was about as big as today's krrokodiler but would Chalk develop into 15-meter reptile that had a head of 2 meters.
Many new corals appeared in the early Triassic and replaced all the species that died out in the Perm later time.
It also came ammonites resembling shells though they were larger and had a fluted shell instead of volutes smooth.
Dom plants that developed during the Triassic was mainly ferns, but there was also a new plant called Bennettit, it reminded pineapple but was about 1.5 meters high.
It was only in the late Triassic as those first dinosaurs were seen on earth.
Then it was mainly Plateosaurus and Fabrosaurus who were ancestors to them later mighty Diplodocus and Tyrannosaurus.
If you tiittar of continental drift as low continents almost stationary, except that China began to approach Pangea, and that judgment smaller islands began to merge himself into larger islands.
Jura 200- 135 million years ago
Jura is usually called the first dinosaur era, even if they first came in the Triassic, it was during the Jurassic dinosaur that development really began. During the Jura began the compact supercontinent Pangea to show signs of fragmentation and it would be a little further into the age, Pangea would shatter into smaller continents during the Cretaceous and the Teritäriska time would attract more and more of them places they lie on today . When Pangea broke up as they came in the middle oceanic ridges up again and pushed up the water so that the water covered the entire 25% of the Earth's total land mass. During the Jurassic so developed some of them känadaste dinosaurs example, Stegosaurus, Diplodocus, which was herbivores, but there was also a carnivore at the name Allosaurus that could be up to 9 feet long. during the Jurassic so developed the first bird, it was called Archaeopteryx and had a wingspan of about 2 meters, it had feathers and teeth and was a fully developed mammals. Even in the water so went development forward, among other things, they came first turtles and various crocodile species entered. Mammalian development is in full swing started well, they varmycket small but began to resemble our mustelids more and more. Conifers, ferns and horsetails plants covered large areas of land in the form of forests and flora dominerda total through their huge development, they first angiosperms may also have been present during the Jurassic, but keeping still insist that they came first in the early Cretaceous. Large parts of the forest ended up as coal, although not as important as the coal was formed during the Carboniferous, but significant for the continuation of life on earth. has been found skeletons of giant Diplodocus in several places in the world, one out of them is found in Denmark. The greatest known skeleton of a Diplodocus is 27 meters long and weighed probably around 40 to 50 kg, so when it went so got the permission to have three bones in the ground all the time or it would fall together by its own enormous weight. Another important piece of bone from the Jura that you found is a tooth from an Allosaurus. The tooth is about 140 million years old and is about 12 cm long, the tooth is also lot of small sharp teeth to byterna could more easily chewed. What is interesting with the big fear lizards is that they are the ancestors of our birds, if you look at almost any dinosaur Either way, it was developed to sprina on two legs and using his arms to almost nothing more than to protect themselves with the battle. Several new insect species emerged during the Jurassic, eg Earwig and caddis came first in the late Jurassic. The lizards began to develop wings and then in Chalk start flying them too, right now did they confine themselves to jump from trees and glide, much like our flying squirrel so they had wings Mellen front and hind legs and still looked like lizards, squirrel looks of course not look like a lizard ...
Chalk 135- 65 million years ago
Chalk, which comes from the word creta is perhaps the most faschinernade era of them all. During the Cretaceous could land encounter 12-meter predators and herbivores which is the ancestor of the rhinos, Triceratops, it was 11 feet long and had a large neck shield and three sharp horns. In the water there was 10 feet long Dinosaurs and 4 meters long turtles. Chalk was a very important era for the plants, among other things, so they started first flowers appear and several new species of trees such as oak and poplar also began to appear in judgment tropical forests. Dom worst water masses that remained from the Jura has now receded and Pangea is soon completely fragmented, Africa has started to drop and drag to the south, while North America starts pulling westward. It was chalk that was the big reptiles time, but it was also during Chalk that almost every creeping thing would die out, more specifically, for about 70 million years ago. Scientists can only conclude that it happened the same phenomenon here that at the end of Perm time. But it can be caused by many things, for example, rapid cooling, the salty sea, the sweet sea, the fragmentation of the continents, increased cosmic radiation, or that it was temporary reversals in the Earth's magnetic field. Anyway died about 75% of all animal and plant life on earth. Before this incident began mammals to evolve more and more and at the end of the Cretaceous there was doglike mammals on earth along with those giant horror lizards. During the Cretaceous became finally the lizards developed to pterosaurs and had wings that could have the wingspan of an impressive 15½ feet. These Pterosaurs named Pteranodon and Quetzalcoatlus and unfortunately so stressed judgment in the strange incident at the end of the Cretaceous. During the Cretaceous, it was no so many new insects but one of those who came were bee, it was about 5 times larger then than it is now.
Newer time (Cenozoic)
That was what happened during the Third Age, the Middle Ages. Now it only remains an era left and it is the Cenozoic or modern times as it is called. The more recent period extending from 65 million years ago to the present, it is divided into two eras, Teritär and Quaternary.
Teritär 65- 1.8 million years ago
Teritär is the first of the two earliest eras, Teritär and Quaternary usually called the mammalian era and it's mostly because when the dinosaurs died out as the road was completely free to take over the Earth. At the beginning of Teritär so was the mammals pretty primitive, but they developed very quickly and at the end of Teritär so had the first human-ape evolved in northern Africa. As for Pangea so most people continents on the way to their natural places, but for North America took a little longer after that they still had a good location up in the heat next to Europe and it would take another few million years before the North released in earnest and looking up its normal position. In the mid and late Teritär so evolved mammals are very fast and it became whales, elephants and many new rodents and deer-like animals came while the youngest orimitiva mammals died out during late Teritär, later, almost to the border of the karts so developed the first few mammals that resembled cats, horses and pigs, if you look at the water so it went on to make up for the loss in chalk by creating new coral and new species larger squid and seaweed. At insect and plant the front so could not progress in any top speed but what happened was above all that körbärsträd and termites began its life here on earth.
Quaternary 1.8 million years tendon Present
It is often said that the Quaternary began at the beginning of the current ice age. In the middle of Quaternary so let North America from Europe and China retreated down to the east and all continents came in their standard locations. During the Quaternary so evolved monkey man from being half ape and half-human to more human and in late Quaternary we have become normal. As for the mammals so they have momentum set to unfold and Bildt several new races while others have died out, for example, mammoths. during the mid-Quaternary so came the first butterfly and hens began to develop more and more. The climate and water level Stabilisers and becomes the water level that we have now.based on 43 ratings EARTH DEVELOPMENT,