Extinction of Dinosaurs Many different theories exist as to why the dinosaurs went extinct. We know for sure most dinosaurs died out around 65 million years ago. The majority of scientists agree on a number of theories as to what brought the end of the dinosaurs. The most popular theory is that an asteroid ended the reign of the dinosaurs. Another theory, massive climate change in the pre-historic atmosphere, caused all the dinosaurs to die. Some scientists believe that mammals out competed dinosaurs for food and other resources. The last theory that dinosaurs died due to a large amount of volcanism comes up in scientists list of theories as well. Many different theories of why dinosaurs went extinct include extinction by asteroid, …show more content…
The power and magnitude of the asteroid is greater than we could ever imagine. If all the world’s atomic weapons went off simultaneously it still wouldn’t cause as much damage as this asteroid did (Erdman). The enormous impact forced large clouds of dust into the air, these clouds blocked the sun causing darkness and extreme climate changes (“What Killed the Dinosaurs”). Out of all the extinction theories the asteroid theory has the most evidence backing it up. As time movies by layers of rock form in the Earth’s crust. The rock formed in the layer around formed the time of extinction contains abnormally large amounts of iridium, a metal found only in asteroids (Erdman). Another piece of evidence found in the rock is impact ejecta. Impact ejecta results from an explosion instantly melting bedrock and throwing it into the air. An abundance of impact ejecta in the rock layer formed near the dinosaur’s extinction suggests that a large asteroid destroyed the dinosaurs (“What Killed the Dinosaurs”). Scientists can locate a layer of rock that formed during extinction because all fossils of a certain species show up under or in a rock layer but never above (“What Killed the Dinosaurs”). “The crater-like shape of the area, the layer rick in iridium and the age of the rocks all lend weight to the theory” (“Eden Channel”). Figure
This researcher proposes that the dinosaurs did not die of heat, in fact she thinks the opposite, that they froze to death instead. Both articles have the same idea about a meteorite hitting the earth yet there is no concrete evidence as to what caused the meteorite to strike and what it did when it got here.
Stephen Gould’s essay “Sex, Drugs, Disasters, and the Extinction of the Dinosaurs” completely agrees with Joseph Williams and Gregory Colomb’s essay “Argument, Critical Thinking, and Rationality.” Gould’s essay deals with three theories for the extinction of the dinosaurs, two of which he argues are entirely invalid because they are not in accordance with the basic rules of argument laid out by Williams and Colomb in their essay. Gould also states that the third theory of dinosaur extinction, natural disaster, follows all the rules that Williams and Colomb espouse, and thus is a sound argument. Gould, Williams, and Colomb all state that the world has a problem with irrational arguments being shoved down people’s throats, and call for a
The scientists believe that the herbivores ran out of plants, and trees and so all of the herbivores died and after all of the herbivores died, all of the Carnivores died as well. Another theory is that a big asteroid hit the Earth, and the asteroid caused a global extinction.. The final theory that the scientists thought of happening was a disease. Disease may of happened from one dinosaur getting sick and then it just passed on from dinosaur to dinosaur.
Gerta Keller, professor of geosciences at Princeton University, has recently conducted research on the Chicxulub asteroid in which she analyzed new core samples taken from the asteroid site (Botzer 2004). These samples indicate that the impact that occurred at Chicxulub actually predated the mass extinction of the dinosaurs, which occurred at the Cretaceous-Tertiary boundary about sixty-five million years ago. Keller claims that the Chicxulub impact occurred approximately 300,000 years before the extinction (Keller 2004). Although previous researchers estimated that the Chicxulub asteroid was the cause of the extinctions, there had always been doubts about the exact age and size of the crater, and about the origin of the “mega tsunami deposits” that were located within the crater (Keller 2004). The focus of Keller’s recent research was on finding some answers to these questions. To do so she analyzed Cretaceous limestone, dolomite, and anhydrite deposits as the site of the Chicxulub crater (Keller 2004).
It is difficult to envision that one of the greatest impact craters on Earth that measures up to 180km wide and 900m deep could just vanish just from sight. There have been many different dinosaur extinction theories offered in the recent decades. These range from poisonous plants to mass suicide by dinosaur herds. Although one concept as to how the dinosaurs became extinct has gained a wide acceptance since the 1980’s, involving a major earth impact by a meteor or comet (Icr.org, 2014). This horrific catastrophic event is thought to have extinguished up to two thirds of all animal and plant species, leaving behind a large crater found in Chicxulub, Mexico (LiveScience.com, 2014).
He narrowed his hunt down to a location in Denmark, where he had sent a colleague to perform an iridium analysis test at ("Asteroids and Dinosaurs: Unexpected Twists and an Unfinished Story," n.d.). When the results came back, Alvarez knew that whatever happened had not been a small-scale disaster. Once again, Alvarez was back to asking questions. What caused the increased iridium levels at the KT boundary? Except this time, he realized that his observations supported the ten year old hypothesis that had been proposed by paleontologist Dale Russell and physicist Wallace Tucker ("Asteroids and Dinosaurs: Unexpected Twists and an Unfinished Story," n.d.). They brought up the possibility of a supernova being the cause of dinosaur extinction. Supernovas are known to release high amounts of iridium, so such a hypothesis fit perfectly with Alvarez’s team’s discovery. However, the hope of having found a conclusion was short-lived. Luis Alvarez had mentioned that if said supernova had occurred that it would have released amounts of plutonium which would have been found alongside the iridium; no plutonium was found at either site. After more digging, the team came up with a new hypothesis ("Asteroids and Dinosaurs: Unexpected Twists and an Unfinished Story," n.d.). Perhaps an asteroid had struck Earth towards the end of the Cretaceous period, blowing enough dust into the atmosphere to
Dinosaurs ruled the earth for over 65 million years and thankfully for the human race, they became extinct. Ultimately, only a major catastrophe could completely wipe out an entire species, let alone an entity of dinosaurs and the debacle on the causes of dinosaur extinction have flooded the minds of paleontologists for centuries. Geologist and zoologist Stephen Jay Gould published “Sex, Drugs, Disasters, and the Extinction of Dinosaurs,” to compare scientific and speculative causes of dinosaur decimation. Personally, I found this passage very informational and enjoyed reading it. Gould provides three theories that capture the reader’s curiosity, allowing room for pondering in one’s mind.
In Stephen Jay Gould’s “Sex, Drugs, Disasters, and the Extinction of Dinosaurs”, Gould investigates three possible theories hypothesizing the reason behind the extinction of dinosaurs. The first theory suggests that dinosaurs became extinct due to a rise in temperature, which caused sperm to die, leading to the sterilization of male dinosaurs. The second hypothesis offer that many dinosaurs consumed bitter plants that contained psychoactive agents which their lives could not detoxify out of their systems. The last speculation about the dinosaur’s extinction is that a large cloud of dust formed in the atmosphere after an asteroid hit Earth’s surface. This dust cloud blocked out the sunlight, causing temperatures to drop and made photosynthesis impossible. Gould uses these three theories to lead to his central claim that science isn’t just about making fascinating claims, but should have a well developed hypothesis.
A crater, the Bedout crater, in Australia has been discovered. A bolide impact would have lead to mass death of marine and terrestrial organisms. The force of the impact could have released methane from stored organic matter and large earthquakes. These earthquakes would have triggered the volcanism in the Siberian traps, leading to the release of large amounts of CO2 and sulfur dioxide. These gases combined with methane previously released would have created a noxious atmosphere, combined with climate change that killed a large scale of life.
The extinction of the dinosaurs, absolutely a thrilling topic. In Steven Gould’s persuasive article he goes into great detail to describe the nature of science and it’s profound nature to help us in the pursuit of knowledge when used correctly. He then begins to describe three scenarios in which could’ve led to the extinction of the dinosaurs in which two while seemingly plausible at first glance are in actuality simply speculation. Thus, just like a good hypothesis using evidence to support his critiques and support of the hypotheses. Which is why I agree with Gould’s statement on how out of the three hypotheses, the extinction of the dinosaurs
There were over 1,000 different species of dinosaurs (“Dinosaurs”) that lived and evolved for almost 185 million years (“Dinosaur Facts”). Dinosaurs were some of the largest and most mysterious creatures to walk the Earth. Dinosaurs have helped scientists to understand the Earth and it 's past by studying different types, how they lived, their characteristics and what caused their mass extinction.
According to the research made by Alvarez (1980), it was due to an asteroid impact that single-handedly destroyed dinosaurs to extinction. Advocacy of this mechanism has been aided by the availability and tangibility of supporting evidence in the form of impact craters- the Chicxulub crater in the Yucatan Peninsula's date and timing of impact (dating produced an almost exact date of 65 million years ago), location, enormous size-170 km (Hildebrand et al.1991) and its high iridium content ( a metal not commonly found at the Earth's surface) make it seem that with a theoretical asteroid 10 km big caused the crater great damage at the end of the Cretaceous (Alvarez et al. 1980).
This final blow would have sent earth into a nuclear winter. According to this theory, dust caused by the asteroid collision disrupted plant growth by blocking out the sunlight needed for photosynthesis for nearly a year. A chain reaction occurred as plants died off, so did the herbivores relying on the plants, and then the carnivores that relied on the herbivores. Around 75% of species became extinct, including dinosaurs, mammals, giant marine lizards, fish, birds, and insects. Meanwhile, seawater flooded around 40% of the world’s continents ("Mass Extinctions").
Nobody can really say what actually eliminated the species, although everyone has their very own idea. Asteroid impact, atmospheric changes (hot to cold), catastrophic eruptions and astronomical events (supernovas etc.). Some have ventured that early mammal inhabitation slowly “pushed” the dinosaurs to extinction. The most favored theory in the scientific field is that of the meteor impact. As always though, knowing when is part of discovering how and why.
Rapid climate change also ends up on the suspect list of possible dinosaur extinction events. During the latter part of the Cretaceous Period continents broke up causing volcanoes to erupt and fill the sky with gas and ash resulting in a drastic climate change (“Dinosaurs Climate Change and Biodiversity”). The shifting of continents changed the Earth’s landscape, altering weather patterns and overall climate (“Dinosaur Extinction Theories”). Also, over a long period of time, climate gradually changed. Ocean habits changed, temperatures grew much more extreme causing scorching summers and frigid winters (Norell, Dingus, and Gaffney). Radical temperature changes like these led to a green-house effect, making life for the dinosaurs a lot