What Really Waped out the DINOSAURS?

world's specThey are the most successful animals on the planet and the most ferocious. They ruled the world fro 100 million years. Some grew to a gigantic size: STEGOSAURUS, DIPLODOCUS, TYRANNOSAURUS REX. Others become fearsome underwater predators, like ICHTHYANSAURUS, and PLESIOSAURUS, while pteranodons, with their vast wingspans, dominated the skies. And then they die and left the way clear to shrew like mammals to evolve into lions, lemurs and lemmings.



The debate what kills the dinosaurs has been equally fearsome. Depending on who we believed.

--- asteroid impact

--- super volcano

--- gamma ray

--- or they were starved, poisoned, frozen, boiled, drowned, asphyxiated, irradiated or all of the above.



According to Shanan Peters, professor of geology at the University of Wisconsin Madison, that Paleontologist are responsible for the third law of mass extinctions: For every extinction, there's an equal and opposite mechanism.


Since life began 3.5 million year sago, there have been five mass extinctions. The dinosaurs died at the last one, 65 million years ago, but the worst at the end of Permian period, 250 million years ago. Known as " The Great Dying , " it wiped out almost 95% of all species. Some scientist suggest that we are now at the brinks of a sixth mass extinction.



It was the changing of sea level that did for the dinosaurs as well as the other species. A few years ago, in the geological time, the world looked rather different. Europe was a shallow sea, 100 meters deep, and a band of ocean ran through the middle of America. This stretch of sea teemed with giant sharks, and mosasaurus--- massive marine predators. As the sea drained away, the sharks and masasaurs became extinct.



The last extinction was triggered by a fall of sea levels, but other has caused by a rise. Scientist arrived at this conclusion by collecting rocks from 540 sites in America. They observed two main type of rocks:


CARBONATES ---- like the white sands in a beautiful marine environments like Bahamas.


SILICICLASTICS --- which are the mud sandy beaches often found in UK, dark with sediment that's been washed off the land.



The Yucatan crater is the biggest crater caused by an asteroids in the last 540 million years, but there are lots of crater now with a diameter of more tha 100 kilometers in diameter, which also caused by a asteroids that aren't linked to any extinctions.


So what led to the rise and fall of sea levels? One explanation is the shift in the Earth's tectonic plates. The other is climate change. Over the past 500 million years, ice sheets have been forming, advancing , melting and retreating. These vast perturbations in the climate change were produced by shifts in the Earth's orbit around the sun. Geologists says this is natural and normal: That we are in the cold phased rigth now.



After the death of dinosaur, one species came to dominate the planet --- and its warming the earth up rather rapidly. The 20th century saw the greatest increase in the temperature of any century in the last thousand years. The last decade has been the warmest since records began. The only similar rate and magnitude of global warming seen in the fossil record was 55 million years ago. Something caused massive amounts of carbon dioxide to be injected into the atmosphere and dramatically altered the climate.



GLOBAL WARMING has led on every continent Scientist examined reports dating back to 1970 and found that in the last 90 percent of cases, shift in the wildlife behavior and populations could only be explained by global warming. The team melting permafrost to retreating glaciers, were caused by the increased in global warming temperature.



But even without global warming , were are going to have a mass extinction, its due to habitat lost , and there's no realistic way were going to avoid that without curtailing human population growth. Extinctions will be insidious. we may not recognized it happened, it means we may not see some species in the past. It's already rare to see large blue butterflies, badgers and bee orchids.




according to Dr. Richard Leakey, the famous paleontologist and author of the book " The Sixth Extinction, " every year between 17000 and 100,000 species vanish from our planet.




By the end of this century, the human populations is predicted to have reached 10 billion and the consequences is thougth to be the lost of half of the worl's total number os species. Leaky says; Homo sapeans is a poised to become the greatest catastrophic agent since a giant asteroid collide with the Earth 65 million years ago, wiping out half of the world species in a geological instant.