Saw that they were different from other fossil and modern reptiles because of: Modern Definition of Dinosauria: The concestor most recent common ancestor of Megalosaurus, Diplodocus, and Iguanodon and all of its descendants Thus, dinosaurs are not just "any fossil animals" or "all fossil reptiles" or "all fossil reptiles of the Mesozoic" or "all giant fossil reptiles of the Mesozoic.
Get Full Essay Get access to this section to get all help you need with your essay and educational issues. The Extinction of Dinosaurs Essay Sample Introduction The Cretaceous Period ended in somewhat what paleontologists see as a catastrophic end to large vertebrates living on Earth during that era.
It was not only the extinction of large vertebrates living on land, sea and air but also of some tropical invertebrates, planktons and some land plants.
Though most of the large vertebrates died out, not all of organisms or living things was wiped out. Insects, mammals, birds, and flowering plants on land, and fishes, corals, and mollusks in the ocean went on to diversify tremendously soon after the end of the Cretaceous.
Cowen, There are numerous theories on how and why this extinction had happen, why some were wiped out and why some other organisms thrive. Cowen, Theories about the extinction Until today, theories are still being developed to give light to what happen to the species that died out and how.
There are many stipulations about it ranging from animal parents killing their own egg and asteroids collapsing on the Earth. Asteroid Theory It was stipulated that a massive asteroid struck Earth that forced the like of dinosaurs to extinction.
The theory was that the dust from the collision infuses in the upper atmosphere which in return has caused global darkness. This phenomenon had created imbalance in marine and terrestrial food chains because the darkness had hampered photosynthesis.
This iridium-enriched layer is present at numerous localities in Europe, North America, and the deep sea. Ausich and Lane The chemical changes in the atmosphere brought about by the asteroid struck was suitable for most of the living things at that time because it was assumed that there were high concentrations of sulfuric acid, nitric acid, and fluoride compounds.
Col, It was said that the asteroid would have been about 15 km big and that except for the hampered photosynthesis, the impact may have also caused disasters within the land to happen like big fires, volcanic eruptions and tsunamis. Col, This theory was first presented by Luis and Walter Alvarez in This theory was supported by the Chicxulub crater that could be found at the tip of the Yucatan Peninsula in the Gulf of Mexico.
It is said that this impact may have been the asteroid that caused the extinction of most species at the K-T boundary. The Chicxulub is an impact crater that is mile-wide km1-mile-deep m. Col, Volcanic Eruption Theory The iridium spike in K-T boundary was assumed to have been because of the basaltic lava eruptions of the Deccan Traps of western India.
It was projected that the same kind of Nuclear Winter brought about by the giant meteor impact was caused by the explosive episodes in and the overspill of lava.
A BRIEF HISTORY OF THE CHANGING CONCEPTIONS OF DINOSAURS. Pre In China, dinosaur bones were called "dragon bones" and were ground up as attheheels.com Europe and America, they were thought to be unfortunate victims of the Great Flood (apparently the Ark was all booked up). An Introduction to Dinosaurs. Search the site GO. Animals and Nature. Dinosaurs Dinosaurs at the National Museum of Natural History in DC. Article. How to Translate Dinosaur Names. List. List. The Dinosaurs and Prehistoric Animals of Illinois. List. 10 Myths About Dinosaur Extinction. List. The Dinosaurs and Prehistoric Animals of. Get the full story behind the extinction of the mammoth species that once roamed the earth.
It was suggested that this happened when the Indian subcontinent passed over the Chagos Archipelago plume as India drifted north to collide with Asia. Blanchard Basalt has little trapped gas in it, and tends to erupt non-explosively, rather flowing smoothly, and sometimes nearly continuously creating volcanic fogs.
Volcanic fogs are produced when sulfur dioxide, from the basaltic volcanic eruptions, react with water vapor in the atmosphere, which in return produces small aerosols of sulfuric acid.
The volcanic fogs caused by the massive volcanic eruption may have been caused the vegetation to obliterate because the thick fog was blocking the sunlight and also causing water sources to be acidic.
Plants and animals may have died because of this, making living stressful for them. Rowland Recent studies has concluded that another continuous volcanic eruption known as the Siberian Trap may have also contributed to the extinction of dinosaurs and some other species during the Cretaceous Period.
Scientists reasoned that because of the continuous eruption, the planet was getting warmer, which is because of large stores of methane gas frozen on the ocean floor that was released.
Ward, a scientist studying this theory, suggested that the normal atmospheric oxygen level is around 21 percent, but evidence indicates that at the time of the Great Dying it dropped to about 16 percent — the equivalent of trying to breathe at the top of a 14,foot mountain. Blanchard It was theorized that a supernova, within 10, light years of the Earth, may have exploded causing the disruption in the chemistry of the atmosphere.
It was specified in one latest theory that a gamma ray beam striking the Earth would break up molecules in the stratosphere, causing the formation of nitrous oxide and other chemicals that would destroy the ozone layer and shroud the planet in brown smog.
That the radiation would be fifty times more than the normal radiation that is enough to kill bare lives. After which the brown smog was said to have caused the ice age as it then triggered the Earth to cool. It said to happen when the core of a star collapses, where part of the core and outer layers are shot outward creating a huge explosion cloud while some parts of the exploded star creates a black hole as they collapses inward.
The earth could have been devastated by a supernova that is within 50 light years away. This could possibly happen because supernova releases huge quantity of electromagnetic radiation that is in parallel to a nuclear bomb.
If enough radioactive matter was released from the supernova, then plants and animals would have died immediately from radiation sickness. The supernova could release a rush of neutrinos causing sickness, mutation, and cancers in plants and animals.
The supernova could have caused increase cloud cover, bringing about a prolonged winter ending in mass starvation. Britt, Galactic Dust Theory The extinction during the K-T boundary been proposed to be because of global warming during that era. The Solar System orbits around the center of the Milky Way galaxy.
Because of the set-up of how the Solar System revolves, from time to time it passes by clouds of unusually thick galactic dust, or clouds of hydrogen gas.Introduction main content. Introduction Part of the Dinosaurs: Ancient Fossils, New discoveries, new technology, and new ideas are helping today's scientists piece together what these living, breathing dinosaurs were really like.
American Museum of Natural History Central Park West at 79th Street New York, NY May 30, · Watch video · The Cretaceous-Tertiary extinction event, or the K-T event, is the name given to the die-off of the dinosaurs and other species that took place some million years ago.
Natural history Habitats.
Dinosaurs lived in many kinds of terrestrial environments, Previous page Introduction. Page 2 of 3 the mass extinction of the dinosaurs and numerous other species near the end of the Cretaceous Period some 66 million years ago. Fortunately, collisions of that sort are rare.
An Introduction to Dinosaurs. Search the site GO. Animals and Nature. Dinosaurs Dinosaurs at the National Museum of Natural History in DC. Article.
How to Translate Dinosaur Names. List. List. The Dinosaurs and Prehistoric Animals of Illinois. List. 10 Myths About Dinosaur Extinction. List. The Dinosaurs and Prehistoric Animals of. A BRIEF HISTORY OF THE CHANGING CONCEPTIONS OF DINOSAURS. Pre In China, dinosaur bones were called "dragon bones" and were ground up as attheheels.com Europe and America, they were thought to be unfortunate victims of the Great Flood (apparently the Ark was all booked up).
The Jurassic dinosaurs Allosaurus (left) and Stegosaurus (right) at the Natural History Museum of Los Angeles Key Points: •"Dinosaur" is not simply a term for any vanished giant reptilian creature.