Theories of the Extinction of the Dinosaurs

328 Words1 Page

Theories of the Extinction of the Dinosaurs

Controversy surrounds the extinction of the dinosaurs. According to one theory, dinosaurs were slowly driven to extinction by environmental changes linked to the creeping withdrawal of shallow seas from the continents at the end of the dinosaur era. Proponents of this theory propose that dinosaurs dwindled in number and variety over several million years.

An opposing theory proposes that the impact of asteroid or comet caused catastrophic destruction of the environment, leading to the extinction of the dinosaurs. Evidence to support this theory includes the discovery of a buried impact crater (thought to be the result of a large comet striking the earth) that is 200 km (124 mi.) in diameter in the Yucatan Peninsula of Mexico. The spray of debris was blown from the edge of the crater. The debris has been found over large regions of North America. Comet enriched material from the impact's fiery explosion was spread all over the world. With radiometric dating, scientists have used the decay rates of certain atoms to date the crater, spray of debris, and fireball layer. Using similar techniques to date the dramatic changes in the record of microscopic fossils, they have found that the impact and the dinosaur extinction occurred nearly simultaneously.

Although great amounts of ash suggest that most of North and South America was devastated by fire from the impact, the longer-term environmental effects of the impact were ultimately more deadly to life than the fire. Dust blocked sunlight from the earth's surface for many months. Burned sulfur from the impact site, water vapor and chlorine from the oceans, and nitrogen from the air combined to produce a worldwide fallout of intensely acidic rain. Scientists postulate that darkness and acid rain caused plant growth to die. As a result, both the herbivorous dinosaurs, which were dependent on plants for food, as well as the carnivorous dinosaurs, which fed on the herbivores, died out. On the other hand, animals such as frogs, lizards, and small insect-eating turtles and mammals, which were dependent on organisms that fed on decaying plant material, were more likely to live.

Show More
Related

  • Analysis Of Paul S. Martin's Twilight Of The Mammoths

    1052 Words  | 3 Pages

    The possibility if a meteor strike as the cause of extinctions is discarded, something that most specialists agree on. There is no evidence of any meteor crater big enough or recent enough to be accountable for it; there are no “elements that are common extraterrestrially but less so on Earth, such as iridium, and no sign of a tsunami or other phenomena following the impact.” The extinctions where also very selective and occurred over a very long period of time. If a “one shot” catastrophe had been the cause it would have affected all species at the same time and in similar

    Read More

  • Sex, Drugs, Disasters, and the Extinction of Dinosaurs by Stephen Jay Gould

    771 Words  | 2 Pages

    The disaster theory, Gould claims, is an example of good science. It has testable evidence and has an impact on studies in other fields of science, it develops further and explains why the extinction of dinosaurs occurred simultaneously with other events. This theory suggests that a large comet hit the Earth sixty five million years ago, causing the cloud of dust to rise into the sky and to block sunlight. As a result, world temperatures went down significantly, the ice age bega...

    Read More

  • Did humans cause the mass extinction of megafauna during the Late Pleistocene period?

    1595 Words  | 4 Pages

    In order to better understand these "implications," it is necessary to define and explain the major theories regarding North American megafaunal extinction. The two most widely supported theories are those of environmental change and overkill. Two theories finding less support within the field are those of hyperdisease and "keystone herbivores."

    Read More

  • The Permian-Triassic Extinction 250 Million Years Ago

    615 Words  | 2 Pages

    The Permian-Triassic Extinction is a mass extinction that occurred between the Permian and Triassic geologic time periods approximately 250 million years ago; it is the deadliest of all extinctions that have occurred on Earth. In addition, during the Permian-Triassic extinction the continents of today existed as one supercontinent known as Pangaea. This was the first time in history where continental or land mass exceeded that of the ocean. This was also before dinosaurs of the Triassic period roamed Earth, during this time animals such as the therapsids, and Synapsids such as the Pelycosaurs, insects and amphibians also occupied Earth. Fauna that existed during the Permian period includes Gymnosperms, or seed producing plants such as the Conifers. Other animals that existed during this time include marine life such as brachiopods (clams), bryozoans (coral-like skeletons), bony fish and sharks, as well as crinoids (sea urchin like creatures). According to National Geographic, about 90 percent of all the animals and fauna of this period perished, the marine life was hit the hardest wi...

    Read More

  • Jarassic Park: The Dinosaurs Were Not To Blame For The Destruction of Jurassic Park

    1116 Words  | 3 Pages

    weather, and the theory says it simply can't be predicted beyond the space of a

    Read More

  • Asteroids Impact Avoidance

    832 Words  | 2 Pages

    However, asteroids are much more deadly. If over-sized meteor can wreck buildings and injure people, then a normal sized asteroid can easily wipe out species if it lands in the right place. As mentioned before, asteroids are much bigger than meteor and much more rare. According to the “Mail Online” 12,000 years ago some type of asteroid slammed into the Northern Canada and some scientist believe that wiped off the mammoths and caused the “Younger Dryas”. Another famous event of asteroids striking, that many scientist believe, was around 65 million years ago asteroids rained and killed of all the dinosaurs 75% of all the life on earth.

    Read More

  • Characteristics and Behaviors of Pterosaurs

    1364 Words  | 3 Pages

    Pterosaurs were not dinosaurs but were closely related, and existed for 150 million years beginning in the late Triassic period through the Jurassic and Cretaceous periods until eventually becoming extinct along with the rest of the earth’s population at what is now known as the KT boundary event. The KT boundary event was the mass extinction that occurred at some point in time between the Cretaceous (K) and the Tertiary (T). This is famous because it marks the end of the 160 million years of dinosaur life. The theory is that asteroid rock hit the earth and caused the mass extinction. 1

    Read More

  • The Permian Triassic Mass Extinction

    581 Words  | 2 Pages

    The eradication of species numbers average at a toll close to one hundred percent of earths total living creatures. “It is the Earth's most severe known extinction event, with up to 96% of all marine species and 70% of terrestrial vertebrate species becoming extinct” (Sahney, and Benton 759). Not only where marine and terrestrial species effected but this catastrophic event is the only recogni...

    Read More

  • What Are Dinosaurs?

    776 Words  | 2 Pages

    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

    Read More

  • Permian Period Mass Extinction

    1113 Words  | 3 Pages

    Throughout Earth’s history there have been many changes. These changes have consisted of temperature fluctuations, atmospheric differentiations, extinctions of various plant and animal life, etc. Over time everything seems to have evolved in some way form or fashion. However, the Permian Era extinction was different from all the rest. This extinction affected every form of life, but especially the marine life. Researchers have stated that 93-97% of all Earths species went extinct during this period of time. This essay will explain how a once blossoming progressive era turned into Earths most catastrophic event.

    Read More

  • Stephen Jay Gould Sex Drugs Disasters And The Extinction Of Dinosaurs

    717 Words  | 2 Pages

    There isn’t a way to test this hypothesis. As a result, this theory holds little water as true science, although it may hold some validity. The second theory of plant chemical overdosing is also speculation. This theory as well has an untestable hypothesis. The theory that dinosaur extinction was a result of a natural disaster is the definition of real science. It is testable and can be furthered. To test this theory, individuals measured levels of iridium in rocks at the time of the dinosaur’s extinction. Therefore, Iridium is a “the source of testable evidence”. Testable evidence is what separates science and speculation. The testing of iridium alerted many other scientists around the globe to test levels in the rocks at their locations. This fueled the hypothesis and made is well publicly known. The other two theories drifted away and are still not well known. Gould then proves how the theory that the extinction of dinosaurs occurred because of a natural disaster has led to other important findings. He proclaims that because of this theory the renowned scientist, Carl Sagan, studied the climate and nuclear warfare. Sagan found that a nuclear holocaust would instill the same dust cloud that caused the mass deaths of dinosaurs due to blocking the sun. This is also why the Cold War was so

    Read More

  • The Cretaceous Extinction Event

    1325 Words  | 3 Pages

    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...

    Read More

  • Extinction On Dinosaurs

    569 Words  | 2 Pages

    seems like it happened so sudden, as geologic time goes, that almost all the dinosaurs

    Read More

  • Mass Extinction

    2446 Words  | 5 Pages

    Several mass extinctions have occurred during the Earth’s history. The Cretaceous – Tertiary Boundary (K-T) Extinction caused the loss of at least three-quarters of all species known at that time including the dinosaurs. The cause of this mass extinction is a controversial subject among scientists but the fossil evidence of it’s occurrence is abundant.

    Read More

  • The Extinction of The Dinosaurs

    1255 Words  | 3 Pages

    The most popular theory of dinosaur extinction, the asteroid theory, says that dinosaurs died out because of a single, giant asteroid. They say that the asteroid that struck the earth near the Gulf of Mexico went 43,000 mph and spanned six miles wide (Erdman). When it hit the Earth the asteroid it left an enormous crater that measured 24 miles deep and 125 miles wide (Erdman). Just the impact of the asteroid destroyed the forests and landscape of the majority of North America due to its massive shock wave (Erdman). Many species went extinct when the asteroid hit, these species include dinosaurs, ammonites (certain ocean dwelling creatures), pterosaurs, and some plant groups dinosaurs, ammonites (mollusks related to the octopus and the chambered nautilus), pterosaurs, and certain plant groups. Although devastating, the asteroid did not wipe out all of the animals on Earth, it didn’t exterminate fish, frogs, turtles, birds, mammals and croco...

    Read More

More about Theories of the Extinction of the Dinosaurs

Open Document