This is the assignment, its for online school.

Good Morning Everyone. Myself xxxxx and today I am going to give my presentation on mass extinction event. As we know that there are different mass extinction events and I have chosen the Triassic- Jurassic period for my presentation. I would like to thank the (name of teacher) for giving us this assignment as I have learnt a lot while doing it.
So these is the contents table and I will be going through the following topics during the presentation. I will be beginning by giving a brief introduction about extinction. Then I will be telling about the Triassic – Jurassic mass extinction event and the causes for the Triassic – Jurassic event. I will also be explaining about the climate, life, fossils of the Triassic and Jurassic period.
The definition of extinction is the amount of life that has rapidly decreased on earth. It means the living organisms including the plants, animals and all the species that gets killed and extinct during a period of time. Now, we can’t predict the time of occurrence of such events as it can occur at any random time interval or it could also be periodic in nature. We use the marine fossils to calculate the extinction rates as they superior fossil record and stratigraphy when compared to land organisms.
Another important point is the difference between extinction and mass extinction. When more than 60% of species and significant geographical and taxonomic impacts are lost within a fairly short geological time, it is considered an event of mass extinction. This can be figure out with the help of the key subdivisions of the geological period.
Now here I have shown the timeline of the five major extinction periods that have occurred. We can see the number of million years for which these extinction events have occurred.
In this slide we can notice the organisms that were affected due to these events. The first row indicates the extinction events that have happened and then the following rows shows the percentage of number of species that got extinct during this period. This percentage represents the number of organisms that got extinct out of the total number of organisms that were found during this period. Also, this percentages have been made according to the different classes of species as well.
Now I am going to explain about the Triassic-Jurassic period. The Triassic extinction occurred (245-208 Million Years Ago) while the Jurassic extinction occurred (208-146 Million Years Ago). This was the transition phase from the Paleozoic Era to the Mesozoic which occurred between the end of the Permian period and the beginning of the Jurassic and lasted from 254 million years ago to 206 million years ago. Similar to other periods, this also had a unique climate and biota indigenous to that time. The paleoclimate was influenced largely by tectonic events that never existed before or since. This event is also considered as the significant because at least half of the now known species that lived on Earth were extinct at that time. Some of the reasons for the cause of this period are the progressive climatic changes, sea level rises and ocean acidified spikes since the late Triassic. The asteroids, greenhouse gases, global warming are some of the factors which are accounted for the occurrence of this event.
Let’s look a deeper look at these reasons. Beginning with sea level falls. These were often marked by sequences of contemporaneous...