The Quaternary Period and Other Periods

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

to many plants and animals on land and in the marine life. There were amphibians and reptiles

The first super-continent- Rodinia broke up and vertebrate life began to colonize the planet. (Ross, Whitmore, Gollmer, Faulkner, 2015). This era is broken up into six time periods: the Cambrian- characterized by the sudden appearance of , Ordovician- characterized by life moving out of the oceans, Silurian- invertebrates appeared, Devonian-the first vertebrates appear, Carboniferous- when coal beds were formed around the earth due to “low-oxygen sedimentary conditions that produced peat” (Ross, Whitmore, Gollmer, Faulkner, 2015) and the Permian- when the extinction of most of the marine invertebrates

The Paleolithic Era V.S. The Neolithic Era I am writing this paper to explain the intricate differences between the arts and cultural backgrounds of the Paleolithic Era and the Neolithic Era. This paper will help to better inform the reader on how the two time periods used art to express their purpose and lifestyles. My main goal is to simply differentiate the art tools and methods used throughout these two Eras by adding specific details and hopefully painting a visual picture in the reader’s mind.

During the Late Devonian period approximately 375 to 360 million years ago, a major extinction of marine life dramatically decreased biodiversity. Researchers state that of the five separate major global mass extinctions, there were only three truly significant mass extinctions on a global level that resulted in a critical drop in diversity: the end-Ordovician, end-Permian, and end-Cretaceous (Bambach et al., 2004). The other two— late Frasnian and end Triassic— do not follow the sequence of remarkable extinction patterns because it is not confirmed that extinction was the primary cause of the decrease in diversity. Nonetheless, for organisms in the marine fossil record, an increase in biodiversity typically precedes extinction, while speciation— the formation of new species as a process of evolution— occurs due to many niches being emptied at once. Increased extinction rates are generally accompanied by increased origination rates which produce new species. This biological evolution is due to competition and predation, interactions that affect species’ population size, density, and geographic range (Alroy, 2008). To conclude, the late Devonian period in which Stigall focused her research witnessed low global biodiversity and, through evidence supported by others’ research, it was subsequently followed by high

The last animal I am going to talk about are the reptiles. During this time, reptiles were changing and evolving quickly. Some reptiles had sharp teeth that is similar to our modern-day crocodile. Others had scaly and thick skin, which would keep them hydrated if they were away from water for a while.There were also small reptiles, whose fossils were found inside tree stumps. Amphibians and fish also thrived during this time. The first dinosaurs like the t-rex, spinosaurus, and velociraptor, were also first appearing.

In all Earth’s history there have been five known mass extinctions, 415, 322, 300, 145, and 33 million years ago (Crawford et al. 2013). The oldest mass extinction happening over 415 million years ago is thought to be caused by a short, but severe ice age while the second oldest, occurring over 322 million years ago almost wiped out the trilobites. The mass extinction is believed to have been caused by the newly evolved plants on the land which released nutrients into the sea, that may have caused algal blooms which used oxygen out of the ocean, suffocating the trilobites and other bottom dwellers. About 300 million years ago, another mass extinction, known as “the Great Dying”, because it was the worst extinction ever. this extreme mass extinction set

There are about thirty modern animal phyla, including chordates, arthropods, annelids, corals, sponges, mollusks and echinoderms. All of which trace back to the Cambrian time period, 530 to 525 million years ago.

During this period in history, the modern Antarctic icecap started to form. Also, the Mediterranean Sea dried up and refilled numerous times due to the drop of sea levels. Nautiloids, crinoids, mammals (Mastodont and Beluga Whale), vascular plants, birds (Condor), corals, gastropods and brachiopods existed during this time. You will be able to find fossils of horses, camels, deer,

The formation of Earth, 4.5 billion years ago till the evolution of hard-shelled animals, about 500 million years ago, is called the Precambrian period. There are many events during this time that are specific and affect the Precambrian life. The earth was formed and the first tectonic plate arose and began to move which caused many variations on the earth conditions during Precambrian that affected atmospheric composition and oceans. The level of oxygen arose in the atmosphere which enabled the enrichment of atmosphere with oxygen reaching its peak about 600 million years ago which enabled the first appearance of animal life that required oxygen for the production of collagen and the formation of skeleton. Also, during this period the ozone

65 million years ago a mass extinction of the dinosaurs took place marking the end of the Cretaceous Period when dinosaurs lived and the beginning of the Tertiary Period when no dinosaurs remained (“Dinosaurs”). This period is also known as the Cretaceous/Tertiary, or K/T Boundary (“Dinosaurs”). Just what caused the mass extinction is still up for debate but the two main theories are either an impact from a huge asteroid or massive strain if

440 million years ago the earth had its first mass extinction, this was during the Ordovician era. The ice caps started growing, taking the water with it. This killed 60 percent of all life. The second extinction took place 360 million years ago among the Devonian

In the sea there were many different forms of life, such as brachiopods, coral, and benthic ( jawless, armored fish). In addition, towards the end of the Devonian, placoderms, the first

Ordovician Period: During the Ordovician Life expanded in diversity tremendously. There were extensive reef complexes in the tropics. The early Ordovician was thought to be quite warm, at least in the tropics. Despite the tremendous expansion of life during the Ordovician Period there was a devastating mass extinction of organisms at the end of the Ordovician. This extinction was one of the greatest mass extinction ever recorded in Earth History with over 100 families going extinct. One of the reasons is that it was the breakup and movement of the large super continent into many fragments. However, modern biology teaches us that this would not likely lead to extinctions, rather it would provide additional niche space for groups to expand into.

The phenology of vertebrates was greatly altered by the mass extinctions and catastrophes that have occurred in history and still have an effect on vertebrates today. The main hypothesis for the global climate change following mass extinctions, particularly the Cretaceous-Paleogene (KPg), is black carbon spread throughout the globe and altered solar radiation to create a system of global cooling (Kaiho et al., 2016). The cooling of the Earth’s temperature created a sudden drop in precipitation and a 50-60% decrease in sunlight following the impact of the asteroid (Kaiho et al., 2016). Research shows that following the impact of the KPg extinction precipitation has substantially decreased and depends on the latitude (Kaiho 2016). The Late Ordovician mass extinction was the first of the “Big Five” and can be clearly connected with climate change (Finnegan et al., 2012). The Late Ordovician mass extinction can be explained by the climactic common cause hypothesis, which states that climate cooling has a direct influence on extinction rates by forcing tropical taxa to live in climates that did not match their niche (Finnegan et al., 2012). In a research study done on the effects of climate change in the Late Ordovician, patterns of thermal tolerance range indicators show cooling and habitat loss as an important driver