Cretaceous Time Period Research Paper

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.

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

Shifting from the end of the Permian period 250 million years ago into the next era, the Triassic period occurred between 250 and 199 million years ago and was know for further diversifying life on land. After the Permian period, the Triassic period was largely successful in adapting and evolving, as the world was going through many changes. The land mass known as Pangea began its separation, which would be completed in the Jurassic period. The climate was relatively more severe during this time, with hotter summers and colder winters, but because of the warmer atmosphere, there were no polar ice caps at this time. Towards the center of Pangea, it was mostly a dry desert climate. As for life on earth, most of the marine life had been wiped

The Cretaceous Period had a similar climate to the Jurassic, warm. The geography, however, was changed a drastic amount from the previous period. The Earth had very high sea levels at this time due to the lack of polar ice caps. The supercontinents Laurasia and Gondwana were breaking apart into the continents that are the same in the present day. Although the continents were the same, they did not yet look exactly the same. The continents will be further shaped by volcanic activity and tectonic plate activity. The shaping of the modern era was under way.

The Cretaceous – Tertiary mass extinction, commonly referred to as the KT extinction, occurred 65 million years ago. As the most recant extinction event it is more easily studied as more evidence has been preserved than for the earlier extinctions. This extinction is the most commonly known, as it is the extinction of the dinosaurs, but the smallest scale mass extinction with only 76% of species dying out.

The Cretaceous period is a period of time within the Mesozoic Era lasting from 146 million years ago to 65.5 million years ago. It is one of three periods in the Mesozoic Era along with the Triassic and Jurassic periods. The Cretaceous period is well known for the amount of dinosaurs it had, and the event that put an end to the dinosaurs reign, the K-T mass extinction. During the K-T mass extinction, a huge asteroid hit earth and caused tons of dust to infiltrate the air. Only a small portion of dinosaurs died on impact Instead, the dust blocked out sunlight which caused plants to die. Without plants, many dinosaurs did not have a food source, so the died out. Carnivore dinosaurs, such as the Tyrannosaurus Rex, survived a little longer

The current locations of the continents and their modern-day inhabitants, including humans, can be traced to this period. The era began on a big down note, catching the tail end of the Cretaceous-Paleogene extinction event at the close of the Cretaceous period that wiped out the remaining non-avian dinosaurs. The global climate of the early portion of the Cenozoic Period was much warmer than it is today, and the overall climate of the Earth was much more consistent regardless of proximity to the

According to a live science, an article written by Mary Bagley, "The Cretaceous Period was the last and longest segment of the Mesozoic Era. It lasted approximately 79 million years, from the minor extinction event that closed the Jurassic Period about 145.5 million years ago to the Cretaceous-Paleogene extinction event dated at 65.5 million years ago"(Mary Bagley, LS). In the cretaceous period, the continent of Pangea was still breaking away from itself, forming what we now know as the seven world continents. In the many eras of dinosaurs, the cretaceous era was responsible for evolving some, but not all the dinosaurs from full land dinosaurs to some who were able to live both on land and in water, semi-aquatic carnivorous dinosaurs. This era had produced some of the dinosaurs that maybe us non- paleontologist are more familiar with like the all mighty tyrannosaurus rex or the long neck. Well let me tell you, there were a lot more dinosaurs than just those two. Although the tyrannosaurs rex was an enormous dinosaur, a bigger dinosaur was discovered in 1912, the Spinosaurus. This discovery would change peoples, kids, and paleontologists view on which dinosaur was bigger than the other. This semi-aquatic dinosaur, Spinosaurus, was much larger than the T-rex due to its sail like backbones that stuck out of its back. Furthermore, spinosaurus had a huge advantage that the tyrannosaurus-rex did not.

Many people often assume the asteroid completely wiped off the land and marine species with just the impact of the asteroid, but was rather the tipping point of what came next. In fact Choi stated that “ "We have shown that these events are synchronous to within a gnat's eyebrow, and therefore, the impact clearly played a major role in extinctions, but it probably wasn't just the impact.” ( Choi). The ultimate reasons for the dinosaurs and other species extinction was the blockage of sunlight which initially darkened and chilled to earth to extreme temperatures ( Jones). At this point many animals and even plants started to die off because of the chilling conditions, but that wasn't the only reason for the extinction of these species. Soon after the dust had settled and the earth was able to receive light, the planet initiated a greenhouse affect. Which not only put the remaining species at high temperatures, but their food also became inhabitable (Choi). The evidence of an asteroid theory is supported by the impact crater, rare metal, melted rock, fractured crystals, and the fossil record (Jones). The impact crater is actually one the main key examples of why the asteroid may have been responsible for the cretaceous mass extinction. It showed the asteroid landing on the Yucatan peninsula, and traveling at 30 kilometers per second (Jones). Not

Another was the formation, about 3 million years ago, of the Isthmus of Panama, which connected North and South America and diverted the oceans’ circulation t a more northward pattern. Since the first northern-hemisphere glaciers formed, 2.6 million years ago, the polar ice caps have expanded and contracted in response to variations in the Earth’s orbit around the Sun, causing cold spells alternating with warmer periods, like the one we live in now. There is no reason to believe that another Ice Age won’t come. In the past, warm cycles lasted about 10,000 years, and it’s been that long since the last cool period. Human-made pollutants may also have an effect on the Earth’s climate cycles. The Pleistone period was between 2 million and 10,000 years ago. This was the time of the “Ice Ages,” when climates alternated between conditions similar to those of the present day, and periods when great glaciers spread over large parts of the Earth. Between 15,000 and 10,000 years ago, many large mammals, including saber-toothed cats, ground sloths, mammoths, and mastodons, became

The fifth, and one of the largest and most well known extinctions in Earths history was the Cretaceous period, where many species, including the dinosaurs, pterosaurs, and large marine reptiles, disappeared. This period was widely known as the K-T period, K being the traditional abbreviation for the Cretaceous Period derived from the German name Kreidezeit, and T being the abbreviation for the Tertiary Period (a historical term for the period of time now covered by the Paleogene and Neogene periods). It was a relatively warm climate and had high global sea levels. The oceans and seas were populated with now extinct marine reptiles, ammonites and rudists, and the land by dinosaurs. At the same time, new groups of mammals and birds as well as flowering plants appeared. The early part of the Cretaceous showed a cooling trend that had been

Why, none other than the Permian-Triassic extinction event 252 million years ago, the planet's most severe extinction. The dinosaurs were just the highest-profile casualty of this event (possibly a meteor impact, possibly a volcanic event, theories abound), which wiped out 70% of all terrestrial species and 96% of all marine species. (Read those numbers again.)

The Jurassic period consisted of 3 major epochs, the first being the Early Jurassic. During the first epoch it was very humid resulting in most of the land mass to be tropical. Also began the major fight for the top of the food chain and the first crocodiles evolved, causing most of the larger amphibians to near extinction. The next epoch was the peak for the reptilian family, due to the abundant predators that had come to be and the large herds of other dinosaurs. The last epoch of the Jurassic Period wasn’t very eventful. Most of the epoch consisted of the ocean rising, introducing more diversification to the new legion of

The Mesozoic Era was when dinosaurs roamed the Earth. During the Mesozoic Era was when life started to live on the land. There were three periods during the Mesozoic Era. The Mesozoic Era last for about 180 million years.

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.