Cambrian Period Essay

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 author and his colleagues specifically chose to focus on 375 million year old rocks in their search for fossils because this was the time frame that provided fish that would be useful to study from. The 385 million year old rocks provided fish that look too similar to the ones we have now and the 365 million year old rocks have fossils that don’t resemble fish. The 375 million year old rocks, however, provide fossils that show the transition between fish and land living animals.

They must be eukaryotic, meaning they have nucleus, and in the domain Eukarya. In the Linnaean classification this could be in the kingdom Protista like a paramecium. Another Linnaean classification of this could be in kingdom Animalia, since they are heterotrophs and their cells contain a nucleus. They could be grouped as predators, since the organism is engulfing another organism. They could also be grouped based on their locomotion. They could have cilia, legs, or even flagella.

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

Fossils Tell of Long Ago uses accessible language and illustrations to aid all students in vocabulary and new concept growth. Explicit instructions, reading the book allowed to the class, and allowing conversation among individual students as they work through learning new words will aid ELL students in expanding their word knowledge. Furthermore, having ELL students translate new word to into their native language will help them activate their previous knowledge. Encouraging all students to be actively engage in learning words will ensure that ELL students and all students will gain knowledge and make connections to new words.

During the Cambrian Period there was an explosion of life forms. Most of these were in the water. Many animals with no backbones lived in the shallow seas. These animals were invertebrates.

Echinoderms such as starfish, sea cucumbers, and urchins are identified by their symmetry and central mouth. This species is found decorating the coral reefs by their variety of color and sizes. Because some of these animals like to burrow in the sand, they can supply oxygen to some of the depths in the ocean. Echinoderms are a staple food in many sea animals diet.

Could not explain the Cambrian explosion, all life forms appeared or disappeared, completely formed totally devoid of transitions.

The most prominent fossils in the Crato Formation are the insects that are preserved. One example of an insect that has been recently found is the Araripenymphes seldeni (as seen in figure 3), an extinct species of lacewing (Myskowiak et al., 2016). The taphonomic classification of A.seldini is: Nymphidae Family Neuroptera Order, and Insecta Class (Myskowiak et al., 2016). This particular species shows sexual dimorphism, a difference in characteristics beyond the sexual organs (Clarkson, 1998). In particular, differences in the wing colouration and wing lengths (Myskowiak et al.,

Deposition of sediments began in the basin during the Cambrian era, but subsidence and basin filling occurred the most during the Ordovician,

The author and his colleagues chose to focus on 375 million year old rocks in their search for fossils because amphibians that look dissimilar to fish were discovered in 365 million year old rocks, while fish without amphibian characteristics were discovered in 385 million year old rocks. Thus, it is possible that the evolutionary intermediary, or the “missing link” between fish and amphibians, would be discovered in 375 million year old rocks, between the two time periods. The rocks examined were sedimentary in composition, as the gradual and relatively gentle formation of sedimentary rock under conditions of mild pressure and low heat are conducive to the fossilization of animal remains. Sedimentary rock is also often formed in rivers and seas, where animals are likely to live. This site provides a resource that describes means by which fossils are formed and how the fossil record may be interpreted, and shows some examples of fossils demonstrating evolution through geological periods: http://www.fossilmuseum.net/fossilrecord.htm. In 2004, Shubin and his colleagues were looking for fossils on Ellesmere Island, in northern Canada. This location was chosen because of its lack of human development, as well as of obstructing natural formations and life forms such as trees, which

The oxygen revolution: During the Proterozoic, biotic system were being established, which gave rise to biomass of the prokaryotic organisms like the “benthic and planktonic photosynthesizing organisms” Due to the vast developing diversity of environment, organisms could well adapt to these various environments, which increased the input of oxygen on Earth. Hence, in order for the oxygen to be accumulated in the atmosphere, Iron and Sulfur like oxygen-sinks had to be depleted.

Spiders can be found in all environments throughout the entire world, except in the air and sea. (Biology of Spiders, R.Foelix) These invertebrates of the order Aranea are one of the several groups of the Class Arachnida, with about thirty four thousand species.

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 first metazoans were soft-bodied, and we have no fossil record of them. But we can look at the tremendous variety of living animals and at the geologic record to try to reason out what the first metazoans might have looked like and what they might have done.