MASS EXTINCTIONS

MASS EXTINCTIONS

After the Cambrian explosion billions of species have existed but 99.9% of them are now extinct,why?The answer is because at this time between Cambrian explosion and present cataclysmic events have done formidable mass extinctions,these mass extinctions are the worst part of our past and could be a part of our future.The first extinction took place 450mya in the Ordovician era,a star exploding and it’s radiation hits the Earth and wiped out 70% of aquatic life on our planet.The next one was the longest,it last for 10 million years,starting 377mya,volcanoes pump out poisonous gasses that fell again in the water as asset rain and kill 65% of life.The next is the mother of extinctions,the Permian extinction,a supervolcano in what is now Siberia erupted and with again asset rain wiped out 95% of life on the planet that looks like the film of 2012.The next is at the end of the Triassic period,a today’s USA volcano erupted,wiped out 80% of life and start the breaking of Pangea.The next you must heard it,it’s the extinction of dinosaurs 65mya,an asteroid 12 miles across slammed in Earth and wiped out 75% of life on Earth.That was the last major extinction in our history.But is 1 question that no one want to hear:Could humanity survived the next extinction?Mass extinctions may hear very bad,but they can change evolution,for our bad or for our good,for example the Ordovician one change the evolution of arthropods with book lungs and give them the ability to breath out of the water the 30% lower oxygen levels.The Devonian extinction give to an amphibian called Ichthyostega legs and lungs to take out of the water,on to dry land.So mass extinctions are not good but not bad,they are something at the centre,yet.

FIRST ORGANISMS ON LAND

FIRST LIFE ON LAND

From the very important and good for me BBC documentary:Walking with Monsters we may thing that the arthropods are the first creatures to went out of the water on to dry land,but this is fault.The first animal to went out of the water is far more in the past unlike the Silurian Brontoscorpios.It was a worm like arthropod that lived 540 million years ago despite the 30% lower oxygen level,is called Aeshia,a strange name for creature.We haven’t to imagine it in life because is a creature that looks like very much to the fossils of Aeshia that live under the cover of darkness in many parts of the tropics inside rotten logs,mostly in Australia and it call as Velvet worm and it’s over like the picture.It’s look like a worm but of course,no worm have legs but is half arthropod,half worm.Aeshia lived in the water and the Velvet worm had lived here for 540 million years and have something that Aeshia might not had,it have tiny holes along it’s flanks,this give it the ability to breathe even the little oxygen that the land had.But it had to change in the next half billion years,unlike it’s half arthropod descendants this creature’s body isn’t covered by an exoskeleton but from soft skin.So that means that their body unsupported by water can’t grow any bigger and they mustn’t dry out for long or they died,they have to stay in damp landscapes.But the scorpions that came later had exoskeleton,so they can live far from water for long without died,the arthropods with this kind of protection they follow the scorpions and went out of the water,so arthropods came more and more out of the water and they became more successful than ever.In the eastern coast of Scotland you may find clues in how successful they became.They are bases of trees that were alive 335 million years ago at a period called Carboniferous,it is the golden age of arthropods.This trees are ancestors of small plants like ferns,but they grew up to 30m at height.They were so many plants that they pump out oxygen and the arthropods got bigger like the 1.5m long Arthropleura,a millipede that feed as well as plants and flesh.Their descendants  today are not bigger than 0.5m long,but they have the 95% of life on land. 

THE MOST HORRIBLE CLAWS

FEARSOME CLAWS

From the dinosaur history we have many questions,I will answer the most strange:Why a giant herbivore need asset of 1,6m claws?At 1948 in the Nemegt Formation in southwestern Mongolia a fossil claw over  long as a human 1,8m tall.Russian paleontologist thought it was the flipper of a giant turtle like reptile,4.5m long,but this were wrong.1970,Anatoly Rozhdestvensky determined that this are claws from a theropod dinosaur.But it thought that it was a dinosaur with the head and body like a Carnosaur and a killing claw on it’s feet like Deinonychosaurs.But finally the correct they named it Therizinosaurus,but it was carnivore?Of course no,it have the claws for protection against predators like Tarbosaurus and packs of Velociraptors.They live in Asia during the late Cretaceous time period,around 83.6-65.5mya.But you probably think that creature have so big claws,it must be a carnivore.No also can be carnivores Triceratops,killing their prey with horns or Stegosaurus using their 1m long spikes on their tales to kill.Therizinosaurus using them not only for protection,they have teeth of a herbivore and claws that can devouring you,so what is that creature?A herbivore or a carnivore,the claws are also using for drag leaves towards their mouths.They move very slow,so they can’t chase prey.But they disappeared 65.5mya along with all the dinosaurs from the meteor strike.But 65 million years later they will be discovered and be a mystery of vertebrate paleontology.

THE GROUND IS MOVING

CONTINENTAL DRIFT

Until 1800 it was thought that the continents any time in the history of Earth were on their today’s positions but then Alexander von Humboldt saw that the S.American eastern coast was fit perfectly with the western coast of Africa,in 1800 he chartographed them to get stuck together.So we know that the continents are moving,the tectonic plates were formed some 3 billion years ago.Then they move and change the face of the planet every day,for example the Atlantic ocean is opening just about our fingernails grow.Australia is moving north faster than every other land mass.450 million years ago a supercontinent Gondwana was formed by S.America,Africa,S.Europe,Australia and Antarctica,the other continents are small land masses near the equator.377 million years ago Antarctica,Africa and S.America are formed still Gondwana the other continents are islands all over the equator.250 million years ago all the continents are stuck together in the biggest continent that ever existed,Pangea.200 million years ago Pangea started to break off, N.America spitted from the supercontinent and started to move on.90 million years B.C. all the continents [except Europe and Asia]are alone in the bigger than today oceans.30 million years ago the continent are just a few miles from their today’s sits.Finally today are as we see them but how the world will like in 5,100 or 200 million years from now?The answer will write in some of the next articles.

A MYSTERIOUS PERIOD

CARBONIFEROUS PERIOD

The fish and once all the kind of invertebrates ruled the seas,the sky by birds and once reptiles and land by mammals and once all vertebrates.But is one question:have ever insects rule the earth?The answer is yes,at a time period called the carboniferous era that started 358mya and ended 298mya.Our story starts with the end of the Devonian era,when our ancestors start to look like more reptilian than amphibian.The plant life start to grow unstoppable,so our cold-blooded ancestors lose size because the climate became wetter and colder.But why the insects ruled at that time,it’s because the oxygen levels began to rise and the insects grow to gigantic sizes.The climate became much wetter and tropical so the amphibians lived in the swamps that were very hot and didn’t lose but take more size.The 50m tall may look like trees but they are actually relatives of ferns.Our 50cm long lizard ancestor called Petrolacosaurus is an easy target for many predators like Mesothelea spider,which  is at the size of a human head,she hide on her underground burrow and when sense prey,strike or the Arthropleura,a 3m long millipede that is omnivore,it ate 1 tonne of vegetation a year and when catch spiders,1m long scorpions and reptiles.it berried it’s shelf alive and when something go under it pop and catch it.The carboniferous era ended with a mass extinction,high oxygen levels mean that everything burns quickly,a storm burn almost all the swamp forests in the world and push oxygen levels down,wipedout all the giant insects and gave to the reptiles the chance of life,in the next period called the Permian the reptiles will rule the land,but in the end of this era 95% of life will be wiped out.

A LIFE EXPLOSION

THE CAMBRIAN EXPLOSION

The Cambrian explosion, wasn’t a explosion of a bomb,but an slow explosion of life that took place 542 million years ago in all around the world,but what happened,why life became so complex in just a few million years?This time we will see.Before the Cambrian period was the most mysterious period in the Earth’s history,the Ediacaran era,all we know about this period came from the Ediacara hills in Australia.But 550 million years ago volcanic activity warm the climate and pulled SO₂ in the oceans and killed almost all the creatures.But 8 million years later the Cambrian explosion took place.-542mya:Nothing yet lives on land except a 10cm worm with legs,but in the oceans it’s a different story.Much creatures lived in the water like Opabinia,the first big predator Anomalacaris,Wiwaxia a primitive snail and our ancestor a 2cm fish called Pikaia,the first animal with a spine.The most of this creatures are Trilobites,there are over 20.000 kinds of them until all of them became extinct 250 million years ago.But why the organisms became in just a few million years so complex?The answer is because right before the life became so complex a global ice age ‘’Snowball Earth’’melted and some microscopic single cells that survived it start to stick together.Oxygen levels were already high in the water so the cells stick together and formed animals.By the time they grow bigger and larger until the Cambrian explosion when the creatures became more big and complex as never before,this event that never happened after it and will never happen again.He laid the evolution of every living or extinct creature today including me and you.

EVOLUTION OF BIRDS

EVOLUTION OF BIRDS

We think that birds evolved from flying dinosaurs that lived in china during the early Cretaceous period,this is wrong.This dinosaurs disappeared 65mya,so how they evolved?The story starts back in the Jurassic with a creature called Ornitholestes,a 2m carnivore that that hunt lizards and mammals and scavenge on eggs.But he have something,the reason that is the ancestor of all birds.His hands are crushed,like all birds today when they landed.His hands became more crushed and at the behind side of them,feathers have evolved for the first time in dinosaurs.In their shadows the gliding dinosaurs evolved but they will vanish.65.5mya:All around the world small theropod dinosaurs have evolved,like Deinonychus in N.America,Velociraptors in Mongolia and the most related to birds,the Alaskan Troodons in Alaska.All of them have feathers and with their large brains they survived the extinction to come and leave behind the small bird like dinosaurs that lived only in China.But right after the dinosaurs they didn’t evolved to modern birds,to 2-3m tall birds that can’t fly but ruled the Earth,the 2m tall birds called Gastornis evolved finally to modern birds from lose size and their wing’s suffuse.But this birds rule every continent except S.America,a very alone and have unique animals continent.Here 3m tall terror birds rule this continent until the saber tooth cats came from N.America and vanished them.Today the birds are as we see them,some are great aerial predators like the falcon,the eagle,scavengers like vulture,some of them live as great swimmers like the penguins or some of them can’t fly like the ostrich.The biggest wingspan is held by the Marabou Stork’s,is over 4m in wingspan and is live now on Africa,meny birds will come,some will can’t fly other may can fly,until as all creatures disappeared.