The dinosaurs were killed in a freak accident caused by a wild meteor slamming into the Earth, or were they? Was the meteor that killed the dinosaurs really just a random event or did Earth’s location in the galaxy play a part in their deaths? Crawford, Filipoic, Horner, Tothill and White have combined their minds to explain their hypothesis about how Earth’s mass extinctions are caused by the solar system’s movement through the Milky Way galaxy’s spiral arms in the article titled, Mass Extinction and the Structure of the Milky Way.
In all Earth’s history there have been five known mass extinctions, 415, 322, 300, 145, and 33 million years ago (Crawford et al. 2013). The oldest mass extinction happening over 415 million years ago is thought to be caused by a short, but severe ice age while the second oldest, occurring over 322 million years ago almost wiped out the trilobites. The mass extinction is believed to have been caused by the newly evolved plants on the land which released nutrients into the sea, that may have caused algal blooms which used oxygen out of the ocean, suffocating the trilobites and other bottom dwellers. About 300 million years ago, another mass extinction, known as “the Great Dying”, because it was the worst extinction ever. this extreme mass extinction set
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The solar system in which Earth is located travels faster than the spiral arms of the Milky Way. When Earth is located inside one of the spiral arms there is a greater density of stars. As the solar system nears a star, the gravitational pull from the star could disrupt the Oort cloud. the Oort cloud is a cluster of comets loosely bound to the Sun by gravity left over from the creation of the solar system. If a star is big enough or close enough to disrupt a comet from the Oort cloud, the comet could crash into the
So what killed the dinosaurs? Without having any background education in science it is hard for the general public to comprehend such matters and they rely on the knowledge of the scientists in this field. Although there has been much research on the subject nobody has come up with a conclusive answer. And we are left to read the countless articles, all having their own opinions as to the mass extinction. One such theory is that a shift in the solar system could have caused the mass destruction. According to an article published in Nature magazine,
Was it the confluence of events outlined in this review (including the prevailing global climate, volcanism), or are some of these factors secondary? For example, we have little idea of the mass of methane hydrates in the Late Permian ocean floor. These and many other questions will need to be addressed before we fully resolve the cause of the end-Permian mass extinction. However, there is a growing realisation that flood basalt volcanism has the potential to be the primary trigger for mass extinctions, rather than meteorite impacts or other external
Nobody knows for sure exactly how the dinosaurs became extinct. However scientists have speculated for decades about possible events that caused the dinosaurs to die out. Possibilities range from asteroids, to volcanoes, to climate changes. One of the more popular or well-known extinction theories involves the belief that an asteroid struck the Earth, causing devastating effects, and triggering mass extinctions around the end of the Cretaceous period.
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.
8. The periods in which there were mass extinctions are Permian – volcanic eruptions which spewed lava and put CO2 into the air which warmed the climate an estimated 6 degrees Celsius. The resulting of oxygen deficiency. And Cretaceous – asteroid or comet
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.
There are several hypotheses that are used to explain the causes of mass extinctions. Climate change, the warming or cooling of global environments over a short period of time, can lead to other occurrences. Shifts in climate can cause extinction by
<b>Introduction</b><br>Think of a world which existed 290 million years ago. As you look out over the terane in front of you, you think that you are on an alien planet. You see volcanoes spewing ash and lava. Beside them is the ocean which is swarming with many different species of echinoderms, bryozoans and brachiopods. As you look down onto the sea floor you are amazed at the countless number of starfish and urchins. Some animals leave you can't even describe and you have no idea even what phylum they belong to. This is a world at its height in diversity of oceanic species. Millions of wonderous species existed at this time in the ocean and most of them will never appear again in earth's history. In the geologic time scale, a million
Since the 1980s the most popular theory for why dinosaurs became extinct was because of a meteor, but many people are skeptical of whether or not the meteor was the only factor in the extinction of the dinosaurs. In Stephen Brusatte’s “What Killed the Dinosaurs,” Dr. Brusatte talks about how the mystery of the extinction of the dinosaurs was a hug influence on his life and caused him to become what he is today. As a teenager Brusatte had a chance to talk to Walter Alvarez, the man who proposed the idea of a meteor being the cause for the extinction of the dinosaurs. Alvarez was able to come up with this hypothesis by examining the clay band between the Cretaceous period and the Paleogene period. The Cretaceous period was a time when the Earth had a surplus amount of dinosaurs and the Paleogene period was the time period directly after the Cretaceous period where dinosaurs had become extinct. When Alvarez studied the clay band he had discovered that the band was saturated in iridium which is an element common on meteors and asteroids. This led him to believe that a meteor may have led to the downfall of the dinosaurs.
The second mass extinction happened to sea creatures once again. Somewhere between 375-360 million years ago, fluctuations of the sea levels in the ocean caused a large portion of Earth’s species to disappear. Another cause would be the changes in climate change, asteroid strikes, or new land plants. Some theories suggest that oxygen depletions in shallow waters caused the Devonian Extinction. Other theories say that algae
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
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).
There have been five well known extinctions on this earth. The one most well known is the mass extinction that ended the dinosaurs. Mass extinction is often described as the elimination of a large number of species in a short period of time. Despite what many think, the elimination of species is almost commonplace at this point. The Earth is currently in the middle of a sixth mass extinction, and it’s been caused by the human race.
Over 98% of all organisms that have lived on Earth are now extinct. A mass extinction event occurs when a large number of species die out within a small time frame (relative to the age of Earth). Mass extinctions are intensively studied for both cause and effect, as there is usually room for debate regarding catalysts that precede the extinction and the massive influx of new biological species that follows. There have been five major mass extinctions, dubbed the “Big Five,” that have wiped out at least 50% of the species living at those times. The most well known mass extinction of the Big Five, with the decimation of every species of non-avian dinosaur, is the Cretaceous-Paleogene
Extinction is the natural path of all species. All species are either being developed, extant, or in the process of becoming extinct. However, there have been 5 times in the earth’s history in which a tremendous amount of extinctions took place in a relatively short period of time. The largest of these mass extinctions was the K-T extinction which wiped out much of the earth’s species, including the dinosaurs. Scientists have firm evidence that a large comet struck the earth at the tip of the Yucatan peninsula causing a large change in habitats and the earth’s atmosphere.