The Jurassic Period is a time period were new dinosaurs were being discovered and found. It was about 199.6 to 145.5 million years ago. Some of the species that were found in the Jurassic Period are the Stegosaurus, Ceratosaurus, Brachiosaurus, and Allosaurus. Each dinosaur had their own characteristics for survival.
The Mesozoic Era was from 248 mya to 65mya. The previous era was Paleozoic and the era after was Cenozoic. The cretaceous period: Upper 96-65 mya, high tectonic and volcanic activity. Primitive marsupials develop. Continents have a modern day look. Minor extinction 82 mya. Ended with large extinction, lower 146-98 the heyday of the dinosaurs. First crocodiles and feathered dinosaurs appear. Jurassic: 208-146 many dinosaurs there's, sauropods,Archaeopteryx, flowering plants,Ammonites, pterosaurs.Triassic: 248-208 mya first dinosaurs appear, mammals, and crocodile forms appear. True flies appear. The temperature in both land and water were much higher than during the Paleozoic period. Climates were more tropical in nature. There were desserts
Some dinosaurs were covered with a type of body armor, and some probably had feathers, like their modern bird relatives. Some moved quickly, while others were lumbering and slow. Most dinosaurs were herbivores, or plant-eaters, but some were carnivorous and hunted or scavenged other dinosaurs in order to survive.At the time the dinosaurs arose, all of the Earth’s continents were connected together in one land mass, now known as Pangaea, and surrounded by one enormous ocean. Pangaea began to break apart into separate continents during the Early Jurassic Period (around 200 million years ago), and dinosaurs would have seen great changes in the world in which they lived over the course of their existence. Dinosaurs mysteriously disappeared at the end of the Cretaceous Period, around 65 million years ago. Many other types of animals, as well as many species of plants, died out around the same time, and numerous competing theories exist as to what caused this mass extinction. In addition to the great volcanic or tectonic activity that was occurring around that time, scientists have also discovered that a giant asteroid hit Earth
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.
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 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
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.
“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…”
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.
The dinosaurs died about sixty-five million years ago. There has been many theories about how the dinosaurs became extinct. Some of
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
this mass extinction is what brought us the jurassic period, and from the Jurassic period, or the
The Cretaceous mass extinction is the most well-known case of meteorite impact on the earth, but it certainly is not the only one. It is merely the most well-known. Due to the impact, debris entered earth's atmosphere and caused the plant life of the time to die off due to the lack of sunlight to survive. This made food much more scarce for the species that were dominant at the time. The competition was simply too much for them, and as the plant life died out, so did the herbivores and then the carnivores died out as well. Not only the land was impacted, however, the sea life was affected heavily by this impact as well. The lack of sunlight caused the oceans to become colder, causing the habitats of many marine animals to be drastically altered
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.
Dinosaur extinction: An analysis of events and theories that possibly led to the dinosaurs' demise.