Dinosaurs

Dinosaurs Life of the dinosaurs

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Dinosaurs were the dominant vertebrate animals of terrestrial ecosystems for over 160 million years, from the late Triassic period (about 230 years ago) to the end of the Cretaceous period (65 million years ago), when most of them became extinct in the Cretaceous–Tertiary extinction event. The 10,000 living species of birds have been classified as dinosaurs. (I got this news on internet because I don’t know how to start… ^^) Talking about the Dinosaurs, every one of us always imagine to a grant-shape with the violent, the cruel which we could see from science-magazines, internet or films… almost things we know about the Dinosaur is depended on fossils which the scientists tried to finding and dissecting since early 19-century. Do you want to know more some details about dinosaurs and their life…? As, when did the dinosaurs first appear on the Earth? .... The oldest dinosaur types are known from rocks in Argentina and Brazil and they are about 230 million years old. Approximately 540 species have been named. However, recent estimates suggest that about 700 to 900 more dinosaur genera may remain to be discovered. Dinosaur life-spans probably varied in length from tens of years to hundreds of years. Some dinosaurs ate lizards, eggs, or early mammals. Some hunted other dinosaurs or scavenged dead animals. Most, eating plants (but not grass, which hadn't evolved yet).Dinosaur probably communicated with others by both vocally and visually. From a scientific viewpoint, the biggest dinosaur we had known is had sciencenamed Argentinosaurus. Early reconstructions estimated Argentinosaurus at 35 meters in length and perhaps 80 to 100 tons in weight. And the smallest dinosaur is only sized 65cm in length and 5.5kg in weight. Nearly 65 million years passed before people appeared on Earth. The last dinosaur had died out.The reason why the dinosaur were extincted ==>Let’s read this on below.

New words: Dominant : thong tri Vertebrate : dong vat co xuong song Terrestrial (tə'restriəl) : song tren mat dat

Ecosystems (´ekou´sistəm) : he sinh thai Cretaceous–Tertiary extinction event : su tuyen chung o ki Phan trang thu 3 Estimate ('estimit - 'estimeit) : su uoc luong Scavenged : bi thoi rua Vocally: tieng noi Visually: thinh giac Lizard: than lan Mammal: nhung dong vat co vu’ Click to top

The extinction of the dinosaurs

Triassic Era Asteroid

Greenhouse Effect

Stress

Brain Functions

Hitting Asteroids

Supernova

Caterpillers

Ozone

No One really when or how exactly dinosaurs became extinct. Actually there's a few people who claim there still is deep in jungles. With this strange mystery comes many theories on the possible reasons to what happened to stop their species. Click to the top links to read about the different ideas. Some are not very realistic and none are proven, so I leave it to you to decide for yourself to which is the most believable.

Did a giant Asteroid make dinosaurs become extinct? Click to top Click to heading2

Image copyright Astronomy

There is proof that an asteroid Over 9 miles wide stuck the earth on the tip of the Yucatan peninsula, in the Gulf of Mexico . Asteroids happen every now and then today, but a big one would be the size of a basket ball nowadays. A 9 mile long asteroid would change atmosphere all over the world. Massive forest fires would spread through countries, severe storms all over the world, poor air quality, ocean to ocean tidal waves, and probably the worst thing ever: It would eliminate ALL sunlight for longer than 6 months. This would surely kill 70% of all life forms. The only that would survive would be smaller animals hiding out through this destruction. The green house Effect cause of dinosaur extinction? Click to top Click to heading2

If you Are not familiar with the term "Greenhouse Effect" then I'll have to brief you on the subject. This is yet another theory on a possible reason why the dinosaurs became extinct. The definition of the greenhouse effect is as follows: The phenomenon where the earth's atmosphere traps solar radiation, caused by the presence in the atmosphere of gases such as carbon dioxide, water vapor, and methane that allow incoming sunlight to pass through but absorb heat radiated back from the earth's surface. I realize this may be confusing to hear but aside from all of the technical words of the definition it's an easy concept. There is a much more easy way to explain this.

If there is a heavy amount of carbon Dioxide in the atmosphere than there is a chance of a greenhouse effect because the carbon dioxide acts like a cloud around the earth and magnifies heat from the sun to the earth. Now this "cloud" is like a blanket and keeps that heat in. The heat has nowhere to go and eventually the earth goes through a faze of higher temperatures. This will create a rise in temperature for the oceans as well. This is a phenomenon change of the environment because this does happen then the ice caps at the artic will start to melt. In the artic there is thousands of miles of pure ice because of the sub-zero temperatures that is there. With the oceans overheating and the atmosphere being at very hot these miles of mountains of ice will melt which will surely make the water levels skyrocket. Changes are half of land will be flooded. In time the melted ice will cool down the planet and the earth will stabilize to the way it was before the greenhouse effect has happened and everything will clear up. This is not something that happens in a day. This is a stage of the world that takes probably over 1000 years from the beginning to the end. After that, we got the earth which is basically a big huge ocean for the most part of it. Actually even today the Gov't is worried that this phenomenon will occur. Ever since the 70's scientists have been mentioning that the ice caps are melting and the earth is currently experiencing a climate change. Of course you don't have to worry about this tonight because like I said before, if it is happening then you won't notice for a decade. Ok, so you understand a bit about the greenhouse effect but how does that come into par with dinosaurs being extent? Well, volcano's create a mass amount of carbon dioxide and if there's a huge outbreak then there is a high chance to trigger a greenhouse effect. But the way the world is now, this isn't going to happen. There simply isn't enough active volcano's around to do this. Volcano activity in the 2000's are not high at all. I couldn't even tell you were or when the last one was. In order to find the time when there was enough volcano activity you would actually have to travel back in time to around 230 million years ago. The cretaceous time which was the last era of dinosaurs right before they became extinct. During the cretaceous era there was major volcano activity. Scientists and Paleontologists claim that during this last prehistoric timeline there was so many volcano's that the world was defaced by them. To them knowing this is simple. When they dig up dinosaurs the ground level of the Triassic and Jurassic period the bones where with dirt, soil, a little bit of clay, and other normal ground. But when they found dinosaur fossils from the cretaceous time there was always special evidence of volcano's in the ground nearby. It could've been a special common mineral that volcano's produce, high levels of sodium, or volcanic rock. So, now you know why everytime you see a dinosaur picture there is a volcano blowing up in the background. Were dinosaurs just not smart enough? Click to top Click to heading2

It's common knowledge that the saying "the strong survive" means that the best life form will stay alive will the weak with struggle or not survive. Through the 2 hundred years of people researching and finding dinosaur remains to them its common knowledge that 99% of dinosaurs had a very small brain. They can tell by the skull fossils and how much space is left for the brain inside as well as certain body features that many dinosaurs had. Most dinosaurs were cold blooded like lizards of today and cold blooded creatures often have been known to be accustom to automatic bodies functions and not decision making unlike mammals and animal do use their brain even as far as problem solving and thinking ahead. If this is true than dinosaurs could be easily endangered to the world evolving because of their inability to cope with it. Therefore they couldn't compete with more efficient life forms and could've been slowly dying off and being endangered and eventually becoming extinct. Asteroid hitting each other made dinosaurs become extinct? Click to top Click to heading2

A joint U.S.-Czech team from Southwest Research Institute (SwRI) and Charles University in Prague suggests that the parent object of asteroid(298) Baptistina disrupted when it was hit by another large asteroid, creating numerous large fragments that would later create the Chicxulub crater on the Yucatan Peninsula as well as the prominent Tycho crater found on the Moon. The team of researchers, including Dr. William Bottke (SwRI), Dr. David Vokrouhlicky ( Charles University , Prague ) and Dr. David Nesvorny (SwRI), combined observations with several different numerical simulations to investigate the Baptistina disruption event and its aftermath. A particular focus of their work was how Baptistina fragments affected the Earth and Moon. At approximately 170 kilometers in diameter and having characteristics similar to carbonaceous chondrite meteorites, the Baptistina parent body resided in the innermost region of the asteroid belt when it was hit by another asteroid estimated to be 60 kilometers in diameter. This catastrophic impact produced what is now known as the Baptistina asteroid family, a cluster of asteroid fragments with similar orbits. According to the team's modeling work, this family originally included approximately 300 bodies larger than 10 kilometers and 140,000 bodies larger than 1 kilometer. Once created, the newly formed fragments' orbits began to slowly evolve due to thermal forces produced when they absorbed sunlight and re-radiated the energy away as heat. According to Bottke, "By carefully modeling these effects and the distance traveled by different-sized fragments from the location of the original collision, we determined that the Baptistina breakup took place 160 million years ago, give or take 20 million years." The gradual spreading of the family caused many fragments to drift into a nearby "dynamical superhighway" where they could escape the main asteroid belt and be delivered to orbits that cross Earth's path. The team's computations suggest that about 20

percent of the surviving multi-kilometer-sized fragments in the Baptistina family were lost in this fashion, with about 2 percent of those objects going on to strike the Earth, a pronounced increase in the number of large asteroids striking Earth. Support for these conclusions comes from the impact history of the Earth and Moon, both of which show evidence of a two-fold increase in the formation rate of large craters over the last 100 to 150 million years. As described by Nesvorny, "The Baptistina bombardment produced a prolonged surge in the impact flux that peaked roughly 100 million years ago. This matches up pretty well with what is known about the impact record." Bottke adds, "We are in the tail end of this shower now. Our simulations suggest that about 20 percent of the present-day, near-Earth asteroid population can be traced back to the Baptistina family." The team then investigated the origins of the 180 kilometer diameter Chicxulub crater, which has been strongly linked to the extinction of the dinosaurs 65 million years ago. Studies of sediment samples and a meteorite from this time period indicate that the Chicxulub impactor had a carbonaceous chondrite composition much like the well-known primitive meteorite Murchison. This composition is enough to rule out many potential impactors but not those from the Baptistina family. Using this information in their simulations, the team found a 90 percent probability that the object that formed the Chicxulub crater was a refugee from the Baptistina family. These simulations also showed there was a 70 percent probability that the lunar crater Tycho, an 85 kilometer crater that formed 108 million years ago, was also produced by a large Baptistina fragment. Tycho is notable for its large size, young age and its prominent rays that extend as far as 1,500 kilometers across the Moon. Vokrouhlicky says, "The probability is smaller than in the case of the Chicxulub crater because nothing is yet known about the nature of the Tycho impactor." This study demonstrates that the collisional and dynamical evolution the main asteroid belt may have significant implications for understanding the geological and biological history of Earth. As Bottke says, "It is likely that more breakup events in the asteroid belt are connected in some fashion to events on the Earth, Moon and other planets. The hunt is on!" The article, "An asteroid breakup 160 Myr ago as the probable source of the K/T impactor," was published in the Sept. 6 issue of Nature Caterpillers the cause of no food for dinosaurs?

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This theory is actually pretty funny to me. I'm not even sure who exactly came up with the idea, but it's a little hard to believe. There was many different types of caterpillars when dinosaurs roamed the earth. Many where much larger than today. It's believed that they were just like insects and reproduced in vast amounts. There is proof that they have gone through several stages of evolution during the cretaceous period. Scientists pose that its very possible that caterpillars could have exhausted the plant life creating a high demand for food to all of the herbivores that habited the world back then. the conclusion is that the herbivores became extinct and the carnivores were soon to follow. The idea of caterpillars being the cause of the extinction of dinosaurs is a far cry from the truth though. Most people don't believe that this has happened. Did the Ozone Layer destroy all of the dinosaurs? Click to top Click to heading2

The sun is the natural source to all life. Without it there cannot be life. But the sun is so powerful that it does create dangerous substances such as the most common ultraviolet rays. Ultraviolet rays create a small amount of radiation which is harmful to all living organisms. It also is known to cause cancer as well, which is fatal. The best way to protect yourself is simply to stay in the shade. Hair and clothes also provide a lot of protection as well. This is where the ozone layer comes into effect to fend off these hazardous and dangerous rays. The ozone layer is like a protective shield against these rays. It blocks most of the harmful energy that the sun sends to the surface of the earth. The ozone layer is roughly 1 ½ miles high in the atmosphere and is transparent to the naked eye. This ozone layer can be damaged by pollution and it's common to hear from scientists that automobiles and big industries are causing damage to the ozone layer. Of course there wasn't cars in the Triassic, Jurassic, and Cretaceous period so ozone should've been in perfect condition during these huge reptiles roamed the earth. Actually there is one natural disaster that can damage the ozone layer really bad. Volcano's. Dinosaur diggers have found that when they dig up dinosaur fossils that are dated from the Cretaceous period they also find a lot of volcano rock in the same area. This is very common, but only for the Cretaceous period. Knowing that, dinosaur researchers were able to assume that during that time they was many outbreaks of volcano's. When a volcano erupted it not only sprays millions of gallons of hot lava, but also a mass of a certain chemical called Hydrochloric acid. This poisonous gas can deface the ozone layer. One volcano would do much harm but scientists know that during the Cretaceous period there was not only one, but mass amounts of aggressive behavior by volcano's around the world.

Most Dinosaurs did not have fur, and many were known not to be like crocodiles laying in water all of the time. This is proven by the way that their bodies are shaped. So we know that they ran around land and if the ozone layer broke apart than cancer is free to spread throughout the world. This would be the beginning of dinosaurs dying off. As for other creatures such as mammals, most of them have fur which does provide enough protection that enough could've survived to get through the ozone damage until it repairs. If you check out other Dinosaur extinction theories you'd realize that many are linked to volcano's because of the proof of that timeline and the loads of volcano rock material found at the same ground level as the latest found dinosaur fossils. The Supernova Exploding Star cause of dinosaur extinction?

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Some Scientists think that a Supernova is to blame for dinosaur Extinction. Although, there is not even an inch of evidence to this theory they simple say its very possible. A Supernova is a Star that explodes and sends a shockwave of the amount of energy of radiation that the Sun creates at an estimate of about 20 billion years. So, in simple words a supernova destroys everything in its path and anything far enough out of the path to not get the explosion may get stomped by mass radiation. This won't destroy the earth but it will kill just about every living thing that isn't buried hiding in a hole for years. The supernova isn't just a exciting fictional belief either. It happens every 50 years or so in the milky way. Did the stress of dinosaurs create physicial problems to make them extinct? Click to top

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A man named Heinrch K. Erben came up with this theory. It's not too proof providing, but does make sense. He was an active Dinosaur egg digger. Over the years he collected a heavy amount of certain species and found a very strange observation. He didn't mention what species of dinosaur it was that he made this assumption on, but regardless it was very interesting. He claimed that the oldest dated dino eggs had a very thick shell and up until the latest dated dino egg which was very thin. The eggs of the same species were getting thinner over millions of years. If this was true then that would mean that there is a high possibility that the chances of a baby dinosaur to develop, hatch, and be immune would be rare. With minimal baby dinosaurs would mean starvation of predators in which would change the whole environment. In the end based on this theory herbivores would increase and exhaust the food and water area's, in which then comes the extinction. Still this doesn't explain dinosaur "STRESS". So we know that the eggs got thinner but the real question you should be asking is WHY?. There's a simple enough answer for this. Certain animals, mammals, insects are known to not be able to handle the pressure of change. If you ever had a fish aquarium you'd know that if you buy a fish you can't just throw it in your aquarium because they have to get used to the different water from the bag its in (from the store) to your tank. The ph levels are different, temperature change, your other fish, different oxygen levels, and the different environment. All of these things will create stress for the fish and its important that it's carefully and gradually brought into that new aquarium. Some life forms do not have this problem. Humans are very efficient with this. In some area's of Mexico the heat out there is so hot that people sleep during the day and work at night. In Canada the winter is long and temperatures reach a low as -45C, but people are doing ok out there. So humans are not sensitive to change. It's been known for quiet some time that some species of modern day birds and lizards have had the same effect with thin eggs because of stress from a change in the

environment. Back when dinosaurs roamed the earth there could have been a large change in the temperatures causing this stress to occur. If this change did actually happen then the estrogen in the dinosaurs would surely cause this thin egg theory. There you have it in a nutshell, errrrr a eggshell, or lack of one. This is a pretty good guess by Heinrch K. Erben, but unfortunately he never was able to back this with more solid proof. It hasn't been proven that he even had the eggs, they were never shown and no one else really has made any finding of eggs that got thinner with the same species. He was the only one who mentioned anything strange about dinosaur eggs to provide evidence of extinction. Come on Heinrch K. The least you could've said is which species of dinosaur you were basing this research on?

Did You Know: Dinosaurs lived and evolved for over 185 million years until they became extinct. The cause has not been proven yet, but many believe that an asteroid Over 9 miles wide hit the earth In the Gulf of Mexico . Minh and Cuong Note: you can do “ctrl+left click “ at the underlined blue texts to get to the target Click to top Click to heading2