The Dinosaur Extinction Mystery By Michael Bento Essay

“A minority disputes this theory, arguing that other events-such as volcanic eruptions, sea-level changes or a series of impacts-were to blame for the spectacular loss of species that occurred at the transition between the Cretaceous and Tertiary periods…”

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

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).

Although the Ediacaran period was well before the first appearance of dinosaurs it shows that there were fossils many years ago. When dinosaurs first appeared things had changed there was still shallow water which meant that bones could be fossilized.

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 the two essays being discussed we learn that science has a vast range of definitions. Science is the effort to understand (or to understand better), the history of the natural world and how the natural world works with observable physical evidence as the base of understanding. Science is about how the hypothesis is developed and how well it is defended.

Assess the different hypotheses put forward for the mass extinctions at the end of the Permian and Cretaceous (KT) Periods.

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.

Every so often a discovery is made that attempts to shake up pre-conceived notions of how the dinosaurs actually lived or how they came to be. On June 22, 2000, in Oregon, scientists announced the discovery of the oldest known animal to have feathers. Though no records indicate how the age of the animal was determined, the

The dinosaurs appeared after the greatest mass extinction event occurred. This is known as the Permian-Triassic extinction. It has been estimated to have occurred around two hundred and fifty million years ago. (6) It is also known as the Great Dying with over ninety percent of species dying off, leaving the Earth essentially a wasteland. It led to the extinction of “57% of all families, 83% of all genera and 90% to 96% of all species. 53% of marine families, 84% of marine genera, about 96% of all marine species and an estimated 70% of land species, including insects.”(7) By the late-Permian, global temperatures were very hot, with them being the highest ever on the planet.

The word dinosaur was invented in 1842 by Richard Owen. Dinosaur comes from the Greek word “deinos” and “sauros” which translates to fearfully great lizard (“Learn about Dinosaurs”). Dinosaurs are always named in Greek and usually named after their unique fossils, where they 're found, it’s size or a person. Before a dinosaur can be officially named it must be approved by the International Commission on Zoological Nomenclature. It’s difficult to figure out how dinosaurs sounded, mated, behaved, what color/pattern they were and which ones are male or female. Paleontologists have however been able to discover that dinosaurs hatch from eggs, their bones have growth rings which can help figure out their age and that the larger dinosaurs lived for roughly 100 years and smaller ones for less. All dinosaurs evolved from other reptiles during the Triassic period. Dinosaurs are either herbivores or carnivores and are divided into two major groups. Bird hipped, Ornithischian, or lizard hipped, Saurischa. In the Saurischa hipped dinosaurs the pubis bone is down and to the front but in Ornithischian hipped it is point down and towards the tail (“Zoom Dinosaur”). The next step was to examine how dinosaurs behaved and their characteristics.

Dinosaur extinction: An analysis of events and theories that possibly led to the dinosaurs' demise.

Jurassic is a period of time with Dinosaurs, rodents and birds. There were also island seas consisting of sharks, sea monsters and blood-red planktons. The existing plants in that period were cycads, ferns and conifers. The Mesozoic era was about 245 million years ago to 65 years ago, so it almost lasted about 180 years in total. The Mesozoic era is divided into three periods of Triassic, Jurassic and Cretaceous. Mesozoic era means middle animals and it is the era, which the word’s fauna has changed from what is in the Paleozoic era and the most famous organisms of this era are dinosaurs. In the Mesozoic era, the extinction of more than 90 percent of species in the earth was observed and the reason behind it was mostly volcanic eruptions and climate changes. On the other hand, this era had massive changes that represented ecological niches and rise to new creatures such as rodent-size mammals and first dinosaurs. In Triassic, which was the first period of Mesozoic, the mammals and first dinosaurs existed. Later than that, the second period was Jurassic, which giant shaped dinosaurs and other kinds of dinosaurs were developed. Besides that the first flowering plants and primitive birds, with long teeth appeared in that era as well.

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

These techniques led to the discovery of the boundary between the two eras. A single thin layer of clay found within predominantly limestone rocks established this. By comparing the marine life found in, above, and below the clay, the marine life, like the dinosaurs, had been terribly affected by the extinction event. The percentage of life in the upper layers was dramatically lower than that in the lower. This was far more compelling than what was suggested by dinosaur’s fossils.