The Cretaceous Er The Last And Longest Segment Of The Mesozoic Era

The big dinosaur t-rex was about 30 feet to 40 feet long and 20 feet tall but can get to 30 feet tall. It lived in the cretaceous period 72 million years ago. It was a carnivore and that means it eats meat it eats more in a week than us eating in 4 months. T-rex is the most powerful with the jaw that can break throw bone.

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.

dinosaur age to the Cretaceous period, to the world we are living in today, where global warming

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

Brusatte did more research on this topic when he was a graduate student when his colleague Richard Butler proposed the idea of both of them together looking at the changes that dinosaurs went through during the ten to fifteen million year before they became extinct. I thought this was very interesting as a reader to see how Brusatte, someone who focuses on early life of dinosaurs and birds combine with someone like Butler who works in the more mathematical side of evolutionary trends. They were able to join forces and research about a single topic in order to discover something they both want to know about. Together they did their research by examining dinosaur diversity trends by using morphological disparity. They learned that most dinosaurs had a steady disparity and only herbivore dinosaurs like horned and duck billed had a declining

According to Holmes, the Time of the Giants begins by looking at the geological and its ecological conditions which creates opportunities for the expansion of dinosaurs in the Middle and Late Jurrasic Epochs. It describes widespread changes to ocean and land enviroments, including worldwide climate changes that served as catalysts for the spread of the jurassic “giants”: the dinosaurs. The book explores the broad ranges of the largest and biggest of all land animalsand tells the discoveries and changing scientific images of the early so-called “giants” over the past one hundred fifty years. By the end of the Jurassic Period, several evolutionary trends were in motion that would be played out by the giant creatures, dinosaurs, in the next

The first dinosaurs were small, meat-eating animals that first arose over 200 million years ago. From such small beginnings evolved thousands of different species, including the largest animals ever to walk on Earth. At the Smithsonian, some of the most important dinosaurs known to science stand in our exhibit halls, from the ferocious Allosarus to eighty-foot Diplodocus. Learn more about our famous dinosaurs

Some may argue that the T-Rex’s unusual anatomy was detrimental to its survival during the Cretaceous era but it actually quite the opposite. One thing the T-Rex is known for its massive disproportionate head, which seems useless but in reality, it helped it become a successful predator and scavenger. “From its thick, heavy skull to its 4-foot-long

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 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

The end-Triassic or Triassic-Jurassic extinction event occurred around 200 million years ago is and thought by numerous have helped dinosaurs to be the dominant species on earth for 135 million years. It additionally finished life for generally 50% of all species that were available around then. Until this event, mammal like animals known as therapsids were much more than the ancestors of the dinosaurs, known as archosaurs. The dinosaurs survived better compared to the early proto-vertebrates, and this extinction event may have altogether tipped it to support them clarifies #########. Of the Big Five, the Triassic-Jurassic extinction event has the least number of current researches. Its cause stays under debate,

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).

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.

The biggest mystery surrounding the dinosaur is how did they die? For over 130 million years dinosaurs ruled the earth. Then 65 million years ago, at the end of the Cretaceous period, they died out.

They say as mammals continued to evolve, they drove the dinosaurs into extinction (“What Killed the Dinosaurs”). “Not only did mammals likely compete with dinosaurs for resources, many species survived the end-Cretaceous extinction and subsequently came to dominate Earth.” (“What Killed the Dinosaurs?”). This is primarily because the early mammals were a lot smaller than the mammals that exist today. “Some of the world's earliest mammals were the multituberculates, a group of small rodent like animals that first emerged on Earth about 165 million years ago.” (Welsh, Jennifer). Scientists predict that any mass extinction event that caused animals to go extinct affected larger animals than it did the smaller animals, such as mammals ("Dinosaurs Became Extinct 'due to Laying Eggs'"). Mammals remained small for almost 100 million years, while they out competed small and baby dinosaurs for food, shelter and resources until they were extinct. Once the dinosaurs were out of the way mammals were able to evolve and grow large in size like the mammals that exist today today (LiveScience). Fossil evidence sheds some light on this theory as well. Fossils of mammals believed to date back to about eighty five million years ago show that mammals began to change rapidly and grow. “This matches up with other mammal groups, including recently discovered species from the Late Cretaceous (between 100 million and 65 million years ago) showing highly specialized