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Hypotheses on the Extinction of Dinosaurs
Hypotheses on the Extinction of Dinosaurs
Hypotheses on the Extinction of Dinosaurs
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Dinosaur
Dinosaurs: Extinct or Natural Causes
As geologic time goes, all the dinosaurs living on earth suddenly disappeared. How did these dominated and gigantic creatures really die? Was it a slow extinction through natural causes, or did it happen suddenly? These questions give rise to many different beliefs on how the dinosaurs disappeared over sixty-five million years ago. Something happened sixty-five million years ago, at the end of the Cretaceous period that was so devastating that it altered the course of life on earth. Extinction is easily defined: the birth rate fails to keep up with the death rate. However, the definition does not answer the question about the nature or causes of extinction. Since so many different causes of death of the dinosaur arose, paleontologists generally divide extinction into two main types. The first is called background extinction, or the isolated extinction of a species due to a variety of cause. Included in these background extinctions is out competition (the fight of the food), depletion of resources in a habitat, changes in climate, development or destruction of a mountain range, river channel migration, eruption of a volcano, the drying of a lake, or the destruction of a forest, grassland, or wetland habitat. The second type of extinction is called mass extinction. There are four main components: Large numbers species go extinct; many types of species go extinct; the effects are global; and the effects occur in a geologically short period of time (Encarta).
The dinosaur could not have lived forever. No creature, plant, and bacteria are forever, not even Homo Sapiens. Extinction is the ultimate fate of all species. One theory on how the dinosaurs became extinc...
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... environmental crisis may have spelled disaster for the dinosaurs. It had to be so sweeping that it affected countless other forms, including the dinosaurs. It is how these successful creatures were eliminated from the planet is a fascinating mystery. however, scientist cannot determine how dinosaurs really became extinct. Perhaps something fell the sky and struck the planet causing a huge dust cloud, utterly shutting out the sun and forcing the dinosaurs into extinction. But why did the little mammals survive, or the crocodiles and birds? Current evidence suggests that the sun or a “greenhouse effect” terminated the dinosaurs sixty-five million years ago (Colbert).
Bibliography:
Colbert, Edwin Harris, 1905- Dinosaurs; Their Discovery and Their World. New York, E. P. Dutton & Co.,INC., 1961, 1st ed.
Encarta Encyclopedia Article, "Dinosaur", 2001
W. H. Freeman and Company, New York. 2) http://www.trueauthority.com/dinosaurs/about.htm 3) Dr. Robert Riesz, University of Toronto, “Ceratopsia and Ornithopoda” http://www.erin.utoronto.ca/w
“Sex, Drugs, Disasters, and the Extinction of Dinosaurs” is written by Stephen Jay Gould, professor of geology and zoology at Harvard. This essay is one of more than a hundred articles on evolution, zoology, and paleontology published by Gould in national magazines and journals. It tells about scientific proposals for the extinction of dinosaurs – a confusing but an exciting problem that humanity tries to solve. By analyzing and describing each of the claims for the reptiles’ demise – sex, drugs, and disasters – Gould differentiates bad science from good science and explains what makes some theories silly speculations, while the other, a testable hypothesis.
The question of what caused the extinction of megafauna during the Late Pleistocene period is one that archaeologists have struggled to answer for decades, but why should it matter? Discovering with certainty the cause of megafaunal extinction would simultaneously prove or disprove any of the proposed implications of each existing theory regarding this massive extinction.
...ories of why dinosaurs went extinct abound, and as there is no theory yet to be truly confirmed as the “right one”, my theory of dinosaur cannibalism is also purely anecdotal. The discovery of the cannibalistic Majungatholus atopus in Madagascar is an important scientific find because it confirms a long-standing theory of cannibalism among certain carnivorous dinosaurs. Behavioral patterns of extinct animals are difficult to establish; however, these bones give authentication to previous unfounded beliefs about the ancient feeding practices of some dinosaurs.
Of course it was the movie Jurassic Park who seemed to coin the phrase “Dino DNA.” This movie gave the public the thought that, a) it is possible to find dinosaur DNA and b) we can clone dinosaurs from this DNA. This essay is not going to pick apart Jurassic Park’s scientific value, however it will share the current knowledge and information on dinosaur DNA. The discovery of DNA is important because it may uncover different bits of information. The idea of cloning dinosaurs, especially at this point is out of the question. It is really hard to clone living animals today, with full DNA and genome strands, we can’t even think about recreating animals millions of years ago.
He explores the theories that a rise in temperature could have made the reptiles of old infertile, or that the dinosaurs ate flowering plants that acted as drugs, causing the beasts to overdose. He goes on to examine a third theory, that of an asteroid hitting the earth and causing a cloud of smoke and dust to cover the sun, dropping temperatures and killing not only the dinosaurs, but much of the life that was present on the Earth at the time. Gould himself leans toward the last theory, citing evidence and research to back his point. All of this, he delivers with an air of humor, saying things such as “How can we possibly decide whether the hypothesis of testicular frying is right or wrong?” (par 21). While the theory of infertility of dinosaurs comes from the idea of rising heat, Gould’s wording here brings to mind a funny image rather than a worldwide epidemic. Using humor again, Gould says “If you talk just about asteroids, dust, and darkness, you simply tell stories no better and no more entertaining than fried testicles or terminal trips” (par 26). Not only does he cast aside the first two theories as useless frivolities, he sets the stage for proving why the asteroid theory is better, using humorous language to do so. A humorous essay such as Gould’s is fun to read, while keeping a basis in
We use dinosaurs to represent the changes in nature that have occurred throughout time. Studies found that although the “oldest rock did not show evidence of life, the progression of plant and animal life that changed in recognizable intervals, from ancient life, age of reptiles to the age of mammals” (Dino Nature Metaphor, slide 6), measured the age of the earth. When we think of dinosaurs in relation to nature, we think of that very powerful force that controls the cycle of life. Nature was able to yield such magnificent ferocious creatures that walked the earth and then take them back when they served nature’s purpose. Dinosaurs fit perfectly in nature’s constant
Dinosaurs are an extinct group of animals that thrived for 165 million years starting 230 million years ago in the Late Triassic period of the Mesozoic Era. Despite being extinct for the past 65 million years and not being able to study them in their true form, scientists have been able to estimate many different behaviors of dinosaurs. This paper will show that the close study and examination of different types of body and trace fossils, along with animal models, can be provided as evidence to estimate different types of behaviors in dinosaurs. The different types of behaviors examined below will fall into the categories of: mating; reproduction and nesting; social lives; locomotion; feeding; and fighting. To begin, a great deal of information gathered from fossils and compared to living animal models have been used to estimate mating behaviors.
A group of scientists from North Carolina and Oregon used medical technology to search an iron-stained concretion inside the specimen’s chest. With the assistance of imaging equipment and software, they were able to reconstruct 3-dimensional structures through the interior of the concretion. The images reveal a heart that was more like that of a bird or a mammal than those of reptiles, significantly adding to evidence suggesting that at least some dinosaurs had high metabolic rates. In addition, the heart appears to have been four chambered with a single aorta, which is most commonly found in mammals or birds.
Paul, Gregory S. Dinosaurs of the air: the evolution and loss of flight in dinosaurs and birds. Baltimore: The John Hopkins University Press, 2002. Print.
The most significant event of the Cretaceous era came at its end. Nearly 65 million years ago, the second most severe mass extinction in earth’s history occurred. This resulted in the loss of around 80% of species living at the time. Though nowhere near as severe as the end-Permian mass extinction, the end-Cretaceous extinction is the most well known mass extinction event. This is due to the violent event that caused it the extinction, as well as the chapter of earth’s history that it closed: the Dinosaurs. The Cretaceous Event ( often shortened to K-T event) Of the animals that were killed off were the flying reptiles (pterosaurs) and the last few mosasaurs and plesiosaurs, both early marine reptiles. Many mollusks and species of microscopic plankton were killed. Terrestrial plants suffered mass extinction as well. Almost 60% of terrestrial plants were lost. This led to high extinction rates among insect populations, especially insects that were highly specialized to feed on just a few types of plants had it the worst. It took approximately 9 million years for the global insect populations to recover from the Cretaceous extinction. Immediately after the extinction, the earth saw an explosion of short term species who respond well to fire, or other external disturbance. Evidence of the catastrophe comes from a thin rock layer deposited worldwide just after the impact. It is dominated by fossil plants whose descendants recover quickly after fires of other disturbances, such as Fire Weed in Alaska. The causes of the Cretaceous extinction are still being debated by paleontologists. Scientists agree that the main cause of the extinction was a...
The dinosaur could not have lived for ever. No creatures, no plants, no tiny bacteria are
...pdated 1995, accessed 3 Sept. 2000), Dino Buzz – What killed The Dinosaurs ? – Current Arguments,
...r of all dinosaurs (Thomas, 2011). It is believed that on the sixth day there were all sorts of dinosaurs, many different types hence proving that the prosauropod were only but a different type of dinosaurs. People also believe that the Bible refers the sauropods as the beast of the earth.
The Jurassic Period of our earth’s history was one of great change. It began with a major extinction even, bounced back, and was yet again the victim of an extinction event. The Jurassic was a flourishing time of new species adapting, changing, and modernizing to suit the ever-changing world they