Friday, March 8, 2013

Module #7

Pick one geological time period or epoch (i.e. Jurrassic) from any of the geological time periods. List and describe three major biological events and three major geological events that occurred during that time period. Provide an explanation and synopsis of one of these events. Be sure to provide a list of websites / sources that you used.

Comment on at least one other posting from a classmate.


  1. Jurassic Period
    3 major geological events

    1. The shifting of Pangea, breaking into Laurasia
    2. Oceans flooded land, resulting in a humid and tropical climate in land, from previous dry, hot climate.
    3. Deserts exposed to water and plant activity starts to take over inland.

    3 major biological events

    1. Shallow oceans formed with abundant life.
    2. Dinosaurs dominate on land, being the greatest predator.
    3. Earliest known bird the Archaeopteryx flew during the late Jurassic period.

    The shifting and transformation of Pangea occurred due to tectonic plates breaking off into many different pieces and bringing segments of land along with them. The breakup of Pangea affected many things including the climate and living conditions. Pangea separated many life forms and made them live and thrive on their own, creating diverse life forms throughout the Earth.


  2. -Permian Period-
    The Permian period was 250-290 million years ago and had many significant events that occurred and helped in the creation and evolutionary parts of our world we know today.

    3 geological events:
    - Sandy shales, sandstones, and thin limestones were deposited, but the continued rising of the land soon put an end to deposition.
    - The Pangaea supercontinent formed from an aggregation of all continents at this time.
    - Appalachian Mountains were created.

    3 biological events:
    - Evolution of insects into flies
    - Evolution of more complex and bigger reptiles
    - End Permian marks the fossil records as the biggest mass extinction in history

    The Appalachian Mountains formed due to convergent plate boundaries. As Pangea formed, the continents that we know today were all pushing and rubbing against each other creating them to ruffle up into mountains. You could demonstrate this with a piece of paper, simply push both sides together and the middle rises, this is what happens slowly but surely everyday on earth. This can also cause earthquakes and potentially volcanoes.

  3. The Devonian Period

    The Devonian Period was a period within the Paleozoic Era which occurred from 359.2 mya to 416 mya. It is popularly known as the “Age of Fishes”.

    In terms of biological events, the most notable would be:
    - The evolution of fish into land mammals. Over time, certain fish grew legs and flourished in the strong vegetation which was found on land.
    - The spread of seed-bearing plants. These allowed for the creation of large, dense forests away from the constricting elements of the previous reproductive methods of plants.
    - The Late Devonian Extinction, which is considered one of the major extinction events in the history of Earth’s biota. It primarily affected the marine life on Earth, most specifically marine creatures living within warm water. Though no one is entirely sure as to the exact causes of the extinctions, many have hypothesized that it was due to asteroid impact, the evolution of plants, and overall global cooling due to lack of CO2 in the atmosphere.

    In terms of geological events, the most notable would be:
    - The collision of North America and Europe, forming the supercontinent Euramerica.
    - The formation of Gondwana, a supercontinent made up of Australia, South America, Africa, Antarctica and India.
    - The beginnings of the Appalachian Mountains began forming due to the collision of North America and Europe.


    - Coffey, Jeffrey. "Devonian Period." Universe Today. N.p., 19 Mar. 2005. Web. 19
    Mar. 2013. .
    - "The Devonian Period." Fossils Facts and Finds. N.p., n.d. Web. 19 Mar. 2013.
    - "The Devonian Period." University of California Museum of Paleontology. N.p.,
    n.d. Web. 19 Mar. 2013. .
    - "Late Devonian Mass Extinctions." Devonian Times. N.p., 9 July 2005. Web. 19
    Mar. 2013. .

  4. Cambrian Period

    Major Geological Events
    1)The global supercontinent of Pannotia was in the process of breaking up in the early parts of this period. Laurentia (North America), Baltica, and Siberia had already separated for the main supercontinent of Gondwana, and the majority of continental land was located in the southern hemisphere and gradually travelling to the north of Earth. The rotational movement of this land mass was very fast, contributing to furthered separation.
    2)With a high sea level in the single world ocean, known as Panthalassa, there was much flooding of continental areas due to the previous melting of glaciers in Snowball Earth. These flooded areas were very large and were warm and shallow, perfect for a rise in life. It was in this way that large epicontinental seas formed over what were mainly low deserts and plains.
    3)Global temperatures rose to much warmer than the temperatures today and melted the glaciers from the previous ice age. No glaciers existed as they were melting and there were no continents at the poles of the earth, so the climate was more equitable than it is now because of the large amount of water and lack of relief.

    Major Biological Events: THE CAMBRIAN EXPLOSION (biology's Big Bang)
    Increased oxygen levels allow organisms in the water to:
    1)grow larger and mulitcellular
    2)mineralize/develop skeletons and hardened body parts such as exoskeletons
    3) develop vertebrae e.g. trilobites and tens of thousands of other plants and animals under waves of the ocean
    HOWEVER on land the sun's deadly radiation with no protective ozone means that the life in the ocean at this point cannot move to land (except for certain algae)




    The triassic period came after the earth’s most deadly mass extinct, in which 90% of species became extinct, and marked the beginning of the Mesozoic era. It also was the beginning of the age of the dinosaur.

    Major Geographical Events

    1) For part of the triassic earth had one supercontinent called Pangea. Later in the triassic Pangea began to break up and slowly formed two new supercontinents. These continents were Laurasia which was in the north and Gondwana in the south.

    2) At this time the climate was very warm. It was so warm that there was no ice at poles and ocean currents kept the continent warm and dry.

    3) The center of the supercontinent, Pangea, was a desert. This desert was in inhabitable and has a very harsh dry climate.

    Major Biological Events

    1) The triassic period is when we saw the first mammals. These mammals still laid eggs but the young would feed on mother’s milk. These creature were shrewlike and about one meter in length.

    2) The first dinosaurs appear at this time. These dinosaurs likely evolved around 230 mya and after the extinction at the end of the triassic they were the only large land animals that survived.

    3) The triassic period would end in a way similar to its beginning. It would end with another great extinction, this event, likely caused by volcanic eruptions or asteroid impact, would wipe out half the earth’s species.

  6. Triassic Period

    The Triassic Period lasted from 250 to 200 million years ago. There were major extinction events at the beginning and end of the period.

    3 Geological Events:

    1: The forming of Earth's continents into the supercontinent Pangaea, the most recent supercontinent to have formed. The continent was made up of most of the Planets landmass.
    2. The Tethys sea formed in Pangaea. It was formed before the Indian and Atlantic oceans.
    3. The sediments in the deep ocean were lost in the subduction of oceanic plates.

    Biological Events:

    1. After the start of the Triassic period, groups of species appeared that still dominate the modern world.
    2. Early forms of frogs came into existence.
    3. Early turtles appeared.


  7. Cretaceous Period
    The Cretaceous Period occurred between 145 mya and 66 mya, marking the end of the Mesozoic Era.
    Major Geological Events:
    1. During this period the super continent Pangaea continued to separate and as continents drifted away from each other the Atlantic Ocean began to form.
    2.The Rocky Mountains began to form at the end of the period in a period of mountain building called Laramide Orogeny.
    3. Large amounts of chalk deposits were formed during this time period due to the eustatic sea levels which covered parts of many continents and due to the warm climate.

    Major Biological Events:
    1.Many insects began to evolve and prosper such as ants, termites, butterflies, moths, bees and grasshoppers
    2. Flora became more diverse throughout the Cretaceous period and evolved with aid from the appearance of bees.
    3. At the end of this period the Earth faced a mass extinction, wiping out 85% of all species on Earth. It is speculated that this mass extinction was caused by a large meteorite. Scientists have found high concentrations of Iridium in a Cretaceous layer of sediment in both marine, and terrestrial. Iridium is also found in high concentration in meteorites. This high concentration in the sediment is said to of only been able to be distributed by a large meteorite that came into contact with the Earth, causing the mass extinction.


  8. Jurassic

    Geological events:
    1) breaking and shifting of continents
    Pangaea into Laurasia and Gondwana
    Laurasia into North America and Eurasia
    Gondwana into Antarctica, Madagascar, India, and Australia
    2)Earth is warm and humid
    3)A lot of plants fill up the land

    Biological Events:
    1)Earliest form of bird created
    2)Organisms in ocean evolved to have similar characteristics of fish today
    3)Dinosaurs dominated land

    The separation and transformations of Pangaea were caused by the movement of tectonic plates, the plates would bring land and oceans with them wherever they moved. This separation caused a lot of live forms to become extinct, and those who did survive then created much more complex life.

  9. Jurassic Period

    The Jurassic Period occurred between 196.6 million years ago to 145.5 million years ago.

    Three Major Geological Events:

    1)The breakup of the supercontinent Pangea, the Northern half separated into North America and Eurasia, the Southern half broke into Antarctica, Madagascar, India, Africa and South America.
    2)Mountains rose of the ocean floor, forcing the sea levels to raise higher, and flood onto the land. The water caused the climate to become hotter and more humid than it was before.
    3)The deserts were also affected by the water, and began growing more plants, and becoming more green, and covered in plants

    Three Major Biological Events:

    1)The earliest known birds appeared in this period.
    2)Dinosaurs ruled the land, and continued to diversify into many different species.
    3)The waters were warm, and full of many new types of fish, and aquatic plants, and reptiles, many of which were beginning to resemble today's fish, and reptiles.

  10. Jurassic Period

    The Jurassic Period occurred from the end of the Triassic Period until the end of the Cretaceous Period. The Jurassic Period is also known as the "Age of the Reptiles."

    Three Major biological Events

    1) The dinosaur was known to dominate the land during the Jurassic Period.
    2) The first birds would appear during the Jurassic Period.
    3) The evolution of Therian mammals would occur during this time period.

    Three Major Geological Events

    1) The supercontinent Pangaea begins to rift into two separate land masses.
    2)The divisions of land masses created more coastlines, resulting in a humid climate. Before this, the continental climate was very dry.
    3) During the Jurassic Period, the dry, desert land of the Triassic Period would transform into lush rainforests covering the entire land mass of earth.

    The Supercontinent Pangaea would split into northern (Laurasia) and Southern(Gondwana) land masses.Eventually, the land would continue to divide into the land masses that we see today. Even today, Earth's continents are slowing drifting apart.

  11. Permian Period

    The Permian Period started 299 million years ago at the end of the Carboniferous Period and ended in the greatest mass extinction ever to occur on Earth.

    Three major biological events

    1) Reptiles adapted to the extreme changes is temperature (below 0 at night and above 38 degrees Celsius during the day) by moving to areas where amphibians previously lived and by having thicker skin
    2) Therapsids became the most dominant species
    3) Permian Extinction takes place at the end of the period

    Three major geological events
    1) Pangaea begins to emerge causing major changes in climate
    2+3) The Theories of the Permian Extinction- main theories are:
    Theory one- Volcanic eruptions- Volcanic eruptions released so much debris into the atmosphere that it blocked out the sun resulting in a major drop in temperature preventing photosynthesis and the food chains collapsing as a result
    Theory two- Sudden large changes in climate, so fast that the creatures on Earth did not have time to adjust resulting in extinction

    The Permian Extinction was the largest mass extinction ever to occur on Earth. It killed off more than 90% of marine species and 70% of land animals. One can still see the effects of this event in what is referred to as "the Black Triangle" located in the hills of the Czech Republic near the German and Polish borders.