The Late Devonian Mass Extinction Period

The Late Devonian Mass Extinction Period
Mass extinction is defined as the global decrease in diversification during a period of time reasons
due to any events that occurred in history of earth. Mass extinction occurs when a great number of
species goes into extinction globally.
The Late Devonian mass extinction is one the 'Big Five' mass extinction in history of earth which
occurred 374.5Ma ago. This extinction event saw at least 70% of species perished; where main
victim of this extinction event were the major reef builders, stromotopoids, rugose and tabulate
corals (McGHee 2012). Causes of this mass extinction event during the late Devonian gathered a
wide variety of debate throughout the years whereby researchers researched substantial theories
supported by evidences. The few ... Show more content on Helpwriting.net ...
This is because most of the species that extinct during this period were warm water marine species.
The sudden change in global temperature could lead to this mass extinction (Elewa 2008).
Evidences of glaciation in Gondwana which were found in Northern Brazil further strengthen and
support this argument (Elewa 2008). The earth was cooled by the effects from asteroid impacts,
volcanic eruptions, biological and chemical weathering was proposed as the cause of mass
extinction (McGHee 2012). Asteroid impact causing global cooling is termed as the impact–winter
theory, whereby the impact of an asteroid injects mass amount of debris, ash and gasses into the
atmosphere which blocks sunlight from reaching the earth surface causing massive glaciation
(McGHee 2012). Sweden, Siljan crater is an evidence of aestroid impact evidence (McGHee 2012),
however recent dating using conodonts stated that the asteroid impact affecting the mass extincition
is not viable as the F–F boundary conodonts was deposited below the iridium layer(Trinajstic pers.
comm. 2014). The massive tectonic movement as continental plates were merging to form super
continent Gondwana, caused high volcanic activity during that period (McGHee 2012). Volcanic
activites which is termed as winter–volcanic hypothesis induces the same effect as the impact–
winter theory as mentioned above. An example would be the Viluy Trap which erupted within the
critical time frame in Late Devonian was one of the key supporting evidence for this hypothesis
(McGHee 2012). Biological and chemical weatherings are two glaciation theories which occurred
gradually over a longer period of time. It was believed that it caused a reverse greenhouse effect
which increased the concentration of oxygen and caused a reduction of carbon dioxide in the
atmosphere. Vast number of plants that bloomed during the Devonian is one of the examples of
biological
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The Greatest Science Papers
That's not hyperbole. I really mean it. How else could I react when I open up the latest issue of
Bioessays, and see this: Cephalopod origin and evolution: A congruent picture emerging from
fossils, development and molecules. Just from the title alone, I'm immediately launched into my
happy place: sitting on a rocky beach on the Pacific Northwest coast, enjoying the sea breeze while
the my wife serves me a big platter of bacon, and the cannula in my hypothalamus slowly drips a
potent cocktail of cocain and ecstasy direct into my pleasure centers...and there's pie for dessert. It's
like the authors know me and sat down to concoct a title where every word would push my buttons.
The content is pretty good, too. It's not perfect; the ... Show more content on Helpwriting.net ...
Movement was no longer by creeping, but used muscular contractions through a siphon to propel the
animal horizontally. Freed from its locomotor function, the foot expanded into manipulating
tentacles.
i–a4650a364628b045d3f57a3baf0e7529–monoplacophoran.jpeg
These early cephalopods, which have shells common in the fossil record, would have spent their
lives bobbing vertically in the water column, bouyed by their shells, and with their tentacles
dangling downward to capture prey. They wouldn't have been particularly mobile – that form of a
cone hanging vertically in the water isn't particularly well–streamlined for horizontal motion – so
the next big innovation was a rotation of the body axis, swiveling the body axis 90° to turn a cone
into a torpedo. There is evidence that many species did this independently.
i–f8e43ceb7154a2f6b4c1b890e7ac4f64–ceph_rotation–thumb–500x331–67138.jpeg
The tilting of the body axes of extant cephalopods. This was a result of a polyphyletic and repeated
trend towards enhanced manoeuverability. The morphological body axes (anterior–posterior, dorso–
ventral) are tilted perpendicularly against functional axes in the transition towards extant
cephalopods.
We can still see vestiges of this rotation in cephalopod embryology. If you look at early embryos of
cephalopods (at the bottom of the

Frasnian-Famennian Extinction
Abstract
The Frasnian–Famennian mass extinction in the Late Devonian has often been considered as one of
the major 5 extinctions through time. Conflicting interpretations for the cause of this extinction
exist, but the role of volcanism is becoming increasingly appealing due to recent advances in
radioisotope dating. New K–Ar and 40Ar/39Ar ages for the Viluy traps in Siberia suggest
multiphase emplacement of the Viluy traps with an early phase likely contributing to the Frasnian–
Famennian mass extinction. Other work supports this idea of multiphase emplacement. Changes in
earth systems during the late Devonian support the argument for the role of volcanism as a root in
the destruction of multiple marine habitats during the Late Devonian. One explanation for the
Frasnian–Famennian extinction involves an initial pulse of Viluy Trap volcanism which lead to
elevated levels in the atmosphere, marine anoxia and ultimately extinction. ... Show more content on
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Rocks associated with the Viluy traps include dikes, sills, and layered basalt breccia, and are
overlain by Late Devonian–Early Carboniferous sediments (Ricci et al., 2013). Previous analysis on
dating the traps has proved difficult due to high rates of erosion and burial by Mesozoic sediments in
the east and Siberian traps to the west (Kiselev et al., 2006). The current extent of the Viluy traps is
800 by 450 km (Gaiduk, 1987; Kiseleve et al., 2006) with a total thickness of sediments up to 9 km
and a volume of about 300X103km3 (Kiselev et al., 2006). However, effects of erosion and burial
through time have likely contributed to a decrease in volume with time, and initial volume likely
reached one million cubic kilometers (Kiselev et al., 2006). Thus, this value is similar to other
volcanic provinces which have been associated with major mass extinctions through time

Johnstown Quadrangle Essay
The Johnstown quadrangle is located in southwest–central Pennsylvania, lying mostly in Cambria
County but also small parts of Somerset, Westmoreland, and Indiana counties. Most of the
quadrangle includes the valley of Conemaugh River and its tributaries, Little Conemaugh River and
Stony Creek, where they run together in the city of Johnstown and its suburbs. The surface rocks of
the Johnstown quadrangle are of sedimentary origin – deposited in or by water – and consist of
sandstone, shale, limestone, coal, iron ore, gravel, etc (Phalen 3). Altogether, the deposits have a
total thickness of 3100 to 3200 feet.
The latest rocks in this region were formed in Pleistocene time as imperfectly consolidated gravel of
river terraces and alluvial deposits of the ... Show more content on Helpwriting.net ...
The quadrangle is considered to be a part of the Allegheny Plateau, so the rocks in this region are
mostly of Carboniferous age. Carboniferous rocks are subdivided into two series: the Pennsylvanian
and Mississippian. The rocks of both series mainly consist of alternating beds of shale and
sandstone, but Mississippian rocks on southern parts of the plateau include thick limestones (Phalen
1). Both series are represented in the Johnstown quadrangle. The Pennsylvanian series, however,
covers most of the region, while Mississippian rocks appear only at the surface along deeply eroded
anticlines.
Below these Carboniferous rocks, Devonian rocks are also exposed. These rocks can be found along
the northern edge and southeastern margin of the plateau, where strata is nearly vertical. These two
geologic systems have also been subdivided into numerous formations categorized according to
their lithologic aspect and the fossil fauna and flora which they

The Devonian Era
The Devonian period initiating approximately 416 Mya and culminating 359 Mya represents a
geologic time period, which characterizes a major part of the Paleozoic Era. Traversing between the
Silurian period (444 – 416 Mya), and Carboniferous period (359 – 299 Mya) the Devonian period
epitomizes substantial modifications in the world's ecology and geography.
In the early Devonian period, also known as the Lochkovian, Pragian and Emsian epoch, due to
substantial tectonic activity, resulted in the convergence of numerous continental land masses,
forming into two supercontinents known as Euramerica and Gondwana. Both these supercontinents
assembled comparatively close to each other in a single hemisphere near the equator and were
surrounded by massive oceans which resulted in the formation of subduction zones. (Sites with a
high rates of earthquakes, volcanism and ... Show more content on Helpwriting.net ...
The plates colliding together produced considerable seismic activity, thus leading to the formation of
the Acadian Mountain range. "The Acadian orogeny is the third of the four orogenies that created
the Appalachian orogeny and subsequent basin." (Faill, 297) Orogeny describes any event that leads
to enormous structural deformation of the Earth's lithosphere due to the interaction between tectonic
plates. This series of Appalachian orogeny resulted in the formation of the Appalachian Mountains
of eastern North America. The formation started in the early Devonian period, however reached its
pinnacle during the mid to late Devonian period. As a result of the newly formed mountain range,
there was extensive erosion, which produced prodigious amounts of sediment, which was then
deposited in lowlands and shallow seas nearby during the mid to late Devonian period. This created
a large amount of new low line continental

Placoderms: A Class Of Armored Flies
Placoderms are an extinct class of armored fishes.Placoderms were the first vertebrates to have jaws.
They are paraphyletic, and comprise several distinct out groups or sister taxa to all living jawed
vertebrates. Placoderms evolved from agnathan (jawless) fishes in the Silurian period, about 425
million years ago. They first appeared in the Early Silurian and diversified dramatically during the
Devonian and Carboniferous periods and became extinct in Permian. About 200 genera of
placoderms evolved during this interval, with the vast majority restricted to the Devonian. Body was
dorsoventrally flattened and divisible into head, trunk and tail. ... Show more content on
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Jaw suspension was autostylic. Internal ear had two semicircular canals. Paired fins were present in
most of the placoderms. They were also the first fish to develop pelvic fins. A long dorsal fin was
present. There is no clear evidence for anal fins. The tail was heterocercal. Placoderms never had
teeth. They grinded their food using sharpened points of bone which protrude from the head. Thus
the method of feeding of placoderms was evolutionary intermediate between jawless fish and
toothed jaws of modern fish. They were mostly bottom dwellers and majority of them were
predators. Males had claspers. They lived in both marine and freshwater

The First Period In The Phanerozoic Eon
The Paleozoic Era was the first in the Phanerozoic Eon. In the Paleozoic Era all life lived in or
around water. This is because land was not sustainable for life yet.The Paleozoic Era had six
different periods. The Era lasted about 542 million years but ended because of the Cambrian
explosion. The first period in the Paleozoic Era was the Cambrian Period. The Cambrian Period was
an important part of Earth's history and formation. It was when mainly all of life first came around.
The second period in the Phanerozoic Era was the Ordovician Period. During the Ordovician Period
most of the land of Earth was mainly in the supercontinent Gondwana.
Thirdly, came the Silurian Period. In the Silurian Period glaciers started to melt. Next came the ...
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The Mesozoic Era was when dinosaurs roamed the Earth. During the Mesozoic Era was when life
started to live on the land. There were three periods during the Mesozoic Era. The Mesozoic Era last
for about 180 million years.
The first period in the Mesozoic Era was the Triassic Period which was the very first time life
started to form on Earth. The Earth was in the form of the supercontinent Pangea. During the
Triassic Period Pangea broke apart into two pieces and formed the continents Laurasia and
Gondwana. The Triassic Period ended about 199 million years ago. Next was the Jurassic Period
which was the period when the Earth went through a major climate change, making it mostly
tropical and humid. This was the period in which Dilophosaurus ruled above all dinosaurs. It ended
about 200– 145 million years ago.
The last period on this Era was the Cretaceous Period. This period was the longest period in the
Mesozoic Era. During this Period the seasons started. The poles got colder. It was also during this
period that the tropical areas were restricted to the equator. Some of the animals in this period were,
Iguanodons, hadrosaurs, and the Tyrannosaurus

Overview of Earth´s History and Periods Essay
Precambrian Era The Precambrian era laster 4600–541 million years ago. During this time, there
were no plant life on the planet. Most of the things that were on the planet were rocks. The most
common type of rock was Isua greenstone. Most rocks have been eroded away, subducted, or
metamorphosed. During this time, the atmospheres and oceans were formed, plate tectonics began to
build up continental masses. The air during this time was mostly made up of water vapor, carbon
dioxide, and nitrogen. Later on, oxygen was formed from early animals taking in carbon dioxide and
releasing oxygen. Scientists know this because oxygen was formed with iron, forming iron oxides
(rust); after there were was no more iron to mix with oxygen, so it would ... Show more content on
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The anthropodes also evolved in this period, and more than 600 types evolved worldwide.
Ordovician Period The Ordovician Period lasted almost 45 million years. During this period, most
of the area was almost entirely ocean, and most of the world's land was collected into the southern
supercontinent Gondwana. Throughout the Ordovician, Gondwana was submerged underwater. This
period is best known for its animals, including graptolites, trilobites, brachiopods, and the
conodonts. Plants invaded the land during this period. The most recent types of like animal was
tetrahedral spores that are similar to land plants have been found, suggesting that plants invaded the
land at this time. Later during the period, the Earth experienced a milder climate; the weather was
warm and the atmosphere contained a lot of moisture. Although, when Gondwana finally settled on
the South Pole, massive glaciers formed, and caused shallow seas, and sea levels to drop. This most
likely caused extinctions at the end of the Ordovician in which 60% of all marine invertebrate
genera and 25% of all families went extinct. The ecosystems was still dominized by algae and
sponges, and in some cases by bryozoans. However, there apparently were also periods of complete
reef collapse because to global disturbances. The major global patterns of life went through changes
during the Ordovician period. Many species of graptolites went extinct by the close of the period,
but the first planktonic

Terrestrial Organism Research Paper
Asia
Mr.Cowart
5th pd.
2/3/16
Compare / Contrast the evolution of Aquatic Organism to Terrestrial Organism. –what did fish
evolve from? What were the different stages of their evolution?
What makes an animal aquatic is if it is a vertebrate or an invertebrate. They live in water for the
MAJORITY of their life, it could breathe air or extract oxygen through its habitat in the water
through their special adaptations such as gills or through its skin. A Terrestrial Organism is basically
the total opposite, these are your animals that live on land, from your friendly pets to the slug snails
living in the backyard.
Important characteristics of terrestrial organism's environment would be to have DRY land in
comparison to an aquatic animal. Oxygen is very important to a terrestrial organisms , it needs to
always be available to the organism. The environmental temperature of the environment is less
stable than in aquatic , ... Show more content on Helpwriting.net ...
With this happening the Devonian has become known as the age of fishes. "The first backboned
"fish" were the Aganthans, which are commonly called jawless fish (Huges, 1996). Agnathans live
today as hagfish and lampreys, but they do not resemble ancient Agnathans (Hamlin, 1999). The
Agnathans lived from 510 to 350 million years ago (Huges, 1996). These fish, since they did not
have a jaw, sucked food in through a hole in their heads (BBC, 1998). One type of Agnathan was the
Hemicyclasis, which had only one nostril and a bony head shield (BBC, 1998)."
(http://hoopermuseum.earthsci.carleton.ca/coelacanth/F11.HTM) The Agnathans were actually
armoured fish but more fish evolved from these first fish. The Acanthodians, or spiny fish, had jaws
unlike the Aganthans. They had a short, deep body, five fins on it's belly and of course, it has spines
all over it's body. These fish went extinct in the Carboniferous

A Feeling For The Organism By Barbara Mcclintock
The class "History of Science" could be translated, according to Dr. Hineline, to "Scientist, Science,
Scientists." That is a reference the three main topic/books covered in class, which include: A Feeling
for the Organism, The Structure of scientific revolution, and The Great Devonian Controversy. The
first of the books, A Feeling for the Organism, is an biography, written by Evelyn Fox Keller, on the
personal and scientific life of the geneticist, Barbara McClintock. The book goes into detail about
the scientific struggles and achievements McClintock had in her field, and how her personality and
beliefs played a role in their creation.
The second book read was the The Structure of Scientific Revolution by Thomas Kuhn. The book is
an in–depth ... Show more content on Helpwriting.net ...
The general definition of science is the systematic study of the physical and natural world through
observation and experiments. On the contrary, it is much more than that. Much like art, it holds a
sense of subjectivity. It is an abstract paradigm that requires the input of one's personal beliefs and
values to help it progress. It is much more than just facts and theories of how the world works, but
also a prime representation of the ethics and beliefs of the scientists that help mold it today. Science
is a database for factual knowledge on the natural world, furthermore, it also incorporates the
environment it has created. The environment consists of the particular people, behaviors, and
struggles of the scientific community. Even though science incorporates many thoughts and ideas, it
does not contain other ideas. Science does not hold a moral category. It does not define what is
considered right and what is considered wrong. It merely provides information on certain ideas for
further understanding. Any theories and applications of it can lead to other subjects. This idea also
applies to what the acquired scientific knowledge is used for. Even though the ideas of complexity
and subjectivity are present in both science and art, the concept of aesthetic should only be
important for art. Despite requiring organization and general cleanliness, science does not need to
pass the eye test. Science should be represented through proper data and its analysis and the non
factual features need to have a rational reasoning. To judge or base an idea on its appeal does not
equal to

Phanerozoic Eras
The earth has been around for 4.6 billion years, and over this time 99.9% of all of the species that
have existed on earth have gone extinct. (Barnosky, et al) Palaeontologists characterize mass
extinctions as times in Earth's history when the Earth loses more than three–quarters of its species in
a geologically short period of time. This has occurred 5 times over the past 540 million years, and
scientists are now suggesting it is happening a 6th time. We are in the midst of a sixth mass
extinction that has the potential to wipe out many species of importance, and humans have a
profound impact on it.
Essentially, there have been 5 mass extinctions during the history of life on earth. (Wake,
Vredenburg) And, the time the earth has existed has been divided up into eons, eras, periods, and
epochs based on the geologic strata of that age. (Impey) There are two eons, the Pre–cambrian and
the Phanerozoic. In the Pre–cambrian there are 3 eras, the Haydean, Archean, and the Proterozoic. In
the Phanerozoic, there are the Paleozoic, Mesozoic, and Cenozoic Eras. In the Paleozoic, there are
seven periods, the Cambrian, Ordovician, Silurian, Devonian, Mississippian, Pennsylvanian, and
Permian. Then for Mesozoic there are three periods, Triassic, Jurassic, Cretaceous. In the ... Show
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In this extinction, approximately 22% of marine families and about 57% of all marine genera went
extinct, this including nearly all jawless fishes. Approximately 3/4 of all species on earth went
extinct in this extinction (BBC Big Five Mass Extinction Events). A global cooling event, after
bolide impacts, could have been the cause behind this extinction, as warm water taxa were mainly
affected by this extinction (Wake, Vredenburg). This extinction event may have actually been a
series of extinctions over several million years instead of one single extinction event (BBC Big Five
Mass Extinction

First Seed Plants False The Earth
How the First Seed Plants Froze the Earth
With a little bacteria and a little bit of dirt, the first plant on earth was created. This plant was no
more than mats of algae that layered on top of itself in water, but it was a first nonetheless. It was
not until the end of the Ordovician period, some 480 million years ago, that plants began to grow on
land. Bryophytes were the first to grow, which included mosses, hornworts, and liverworts. Lacking
any leaves, these plants went through a Gametophyte stage, reproducing by dividing cells into
spores. Also reproducing with spores, the Lycopodiophyta (Lycopods) evolved simple microphyll
leaves with just one leaf vein bringing sunlight and nutrients in to support the plant.
The beginning of the Silurian Period (440 million years ago) brought vascular plants such as ferns,
with megaphyll leaves, or many veined leaves, ... Show more content on Helpwriting.net ...
The lignins in plants becomes buried over time, not allowing the carbon atoms to release back into
the atmosphere. Two historic climate changes that took place around the same time could possible
be explained by the evolution of seed plants. The first is the Snowball earth theory that suggest the
equator and therefore the whole earth was at one point completely covered in ice. Evidence for this
theory is found in earthforms that contain markings similar to those that glaciers make. Another
theory is the Cambrian explosion which resulted in creating the first fossils of every animals
category. There are still many debated and unproven theories about the evolution of plants but one
thing that is for certain is that they had one of the largest impacts on the planet, shaping the
atmosphere and biosphere the most in establishing conditions to support animal life, by supporting
the soil, air, water, food supply, shelter, and much

History Of Mass Extinction Essay
The History of Earth's Mass Extinctions
The four billion year history of earth has witnessed five mass extinctions, and some scientists
believe that we are on the verge of the sixth.1[1] If we are in the midst of the next mass extinction,
we are in the very early stages of an evolving, and escalating process. The most recent, or fifth mass
of the extinctions occurred 65 million years ago at the boundary between the Cretaceous and
Tertiary periods. Images of an asteroid colliding with the planet, decimating the dinosaur population
have been in circulation since the early 80's.2[2] Being the most recent mass extinction, thousands
of scientists around the world have investigated it, and elementary school children are familiar with
... Show more content on Helpwriting.net ...
Experts have put together various theories about previous mass extinctions and their findings have
led some to believe that we are in the early stages of the sixth. One finding that has worried
scientists throughout the world is the rate at which species of plants and animals have been going
extinct. Previous research had discovered that the number of species of birds around the world has
been on a steady decline for some time.6[6] While this detection did raise some red flags, it was not
evidence that the next mass extinction had been launched.
While birds are abundant both in sheer population and number of species scientists needed to
discover the decline of more than one selection of animals. More than half of the detected species of
animals on earth are insects.7[7] If scientists wanted substantial, tangible evidence that there was a
widespread decrease in animal populations and worldwide decrease in biodiversity, researching
insects was the way to go. The results across the board were not the least encouraging.
The populations of butterflies in Britain were at the forefront of the researchers' findings. Overall,
71 percent of the butterfly populations have decreased in numbers and 3.4 percent of

Western Cordillera
The western Cordilleran orogenic belt had been depicted as a passive margin after Neoproterozoic to
Early Cambrian rifting. Afterwards, the passive margin converted to an active margin most probably
about Late Devonian to Late Cretaceous through the subduction of the exotic allochthons beneath
the North American plate. The late Jurassic to Cretaceous subduction of (Sevier and Laramide
Orogeny) representing as a period of the back thrust, intraplate thrusting, behind a magmatic arc on
the upper plate near or on its westernmost margin from the latest Devonian until the Cretaceous.
Hildebrand (2009, 2013) cast doubt the back thrust interpretation of the western US Cordillera.
Hildebrand (2009, 2013) proposed that western North America was a ... Show more content on
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In addition, per my knowledge none of the western US geologists have documented passive margin
deposits as young as of upper Paleozoic age or younger. Therefore, Hildebrand (2009, 2013)
hypothesis faces deficiency to explain the thrusting of Roberts Mountain and the emplacement of
the Proterozoic rocks over the rocks of Lower Paleozoic age. Thus, the western Cordillera have been
converted to an active margin prior to 124 Ma which is contradict with Hildebrand's hypothesis
(2009, 2013). Hildebrand, (2009, 2003) attempts to integrate both observed geologic features
(hinterland high grade metamorphism, Laramide basement uplifts, Cordilleran batholiths, regional–
scale Neogene extension) and the lack of observed features (large scale strike/slip faults), while
matching paleomagnetic data (large amounts of northward motion in the oceanic realm exist with no
evidence on land) (Fern Esperanza beetle–Moorcroft, MS Thesis, 2014). However, Hildebrand,
(2009, 2013) affiliate the pre Cretaceous rocks, particularly the Neoproterozoic rocks crops out in
central and east Utah, to the microcontinent Rubia, but such interpretation needs translation of rocks
for a very long

Late Devonian Calculation Paper
Abstract
Late Devonian paleoclimate proxy records indicate substantial sea level variations, however a
thorough understanding of the Late Devonian climate and the causes of these fluctuations remain
uncertain. Numerous theories, including glaciation, bolide impacts, global anoxia, and the spreading
of land plants are attributed to these events. This paper attempts to test the plausibility of the
glaciation hypothesis by applying Late Devonian boundary conditions to a general circulation model
(GCM). A Late Devonian paleo–reconstruction is combined with soil and vegetation, pCO2, and
obliquity parameters. Temperature and precipitation patterns indicate that it is possible for mountain
glaciers to form in regions of Gondwana that have both high latitude and altitude. However, because
there is a low temperature gradient between the equator and poles, the climate is comparable to
post–industrial greenhouse climates. Therefore, these GCM simulations provide a greater
understanding of Late Devonian climate conditions and add validity to Late Devonian glaciation. ...
3c) (De Vleeschoucer, et al., 2014). These simulations suggest that it was possible for mountain
glaciers to form on Gondwana in locations of both high altitude and latitude. An average monthly
temperature of 37 °C is recorded at tropical Gondwanan latitudes and the highest land temperatures
appear in January (Fig 4b)(De Vleeschoucer et al., 2014). Compared to modern pre–industrial
simulations, Late Devonian sea surface temperatures are significantly higher. At 60° S this
difference is 13 °C and 1.2 °C at the equator (Fig. 4a). Therefore, the Late Devonian climate has a
low pole–to–equator temperature gradient and is comparable to post–industrial greenhouse climates
(De Vleeschouwer et al.,

Goniatites Research Paper
Goniatitida
All Goniatites have an external shell which is internally divided into gas chambers. This gives
buoyancy during the life of the animal.
The morphology and habit of the goniatites, compared to the ammonites, are alike. For example,
both swim freely and have heads with two well developed eyes and arms (or tentacles).
Survived the Late Devonian extinction. (One of five major extinction events in Earth's history)
The shell of a Goniatite is always coiled in a planispiral structure. According to the shape of its
shell, this order was thought to be poor swimmers.
Prolecanitida
An order of ammonoid cephalopods that are extinct and possess discoidal to thinly, convex lentil–
shaped shells.
Within the Ammonoidea, a small and stable order

Index Fossils Research Paper
Index fossils are fossils used to define and identify geologic patterns. They work on the premise
that, although different sediments may look different depending on the conditions under which they
were laid down. They may include the remains of the same species of fossils. If the concerned
species was short–lived (only lasting a few hundred thousand years) then it is certain that the
sediments were deposited within that narrow time period. The shorter the lifespan of the species, the
more precisely different sediments can be correlated, and so rapidly evolving types of fossils are
particularly valuable. The best index fossils have 4 characteristics: they are unique, prevalent,
plentiful, and restricted in geologic time. Most fossils are from

Cretaceous-Paleogene: The Most Well-Known Mass Extinction
There have been 5 mass extinctions in Earth's existence. The names of these are (from most recent
to least recent): Cretaceous–Paleogene, Triassic–Jurassic, Permian–Triassic, Late Devonian, and
Ordovician–Silurian. The most well known mass extinction, Cretaceous–Paleogene, was theorized
to have occurred through a massive comet or asteroid impact. A cold winter created by the
impacting object forbid any plants and plankton to carry out photosynthesis. During this time, about
three quarters of all life went extinct. This happened approximately 66 million years ago. Most life
forms went extinct, with some ectothermic species and tetrapods weighing less than 25 pounds.
Although everything seemed to look hopeless, adaptive radiation caused evolution

Ordovician Extinction Research Paper
Are we on the brink of a sixth mass extinction? Many say yes, but there is also hard evidence saying
no. Nonetheless, scientists can prove five mass extinctions in history. The first mass extinction
happened roughly around 445 million years ago. It was named the Ordovician Extinction. The
species affected were known as Graptolite, which are different types of sea creatures. Their demise
on Earth lasted around only one million years. Around sixty to seventy percent of the species
disappeared, and now the remaining species have evolved into something new. The extinction was
likely because of a short and dangerous ice age, or the formation of the Appalachian mountains. It
was likely that glaciers formed over the oceans and caused the sea levels to rapidly drop, killing the
species.
The second mass extinction happened to sea creatures once again. Somewhere between 375–360
million years ago, fluctuations of the sea levels in the ocean caused a large portion of Earth's species
to disappear. Another cause would be the changes in climate change, asteroid strikes, or new land
plants. Some theories suggest that oxygen depletions in shallow waters caused the Devonian
Extinction. Other theories say that algae ... Show more content on Helpwriting.net ...
The most likely cause of the extinction were asteroids or volcanic activity. Roughly ninety–six
percent of the species on Earth disappeared. It was nicknamed The Great Dying. It happened around
250–253 million years ago. Scientists disagree on whether the extinction happened over the course
of millions of years, or whether in happened in a short 200,000 year period. This was the only
extinction to take out insects. It also took out coral, which means today's coral is an entirely
different group of coral. An eruption by Siberia blasted carbon dioxide into the atmosphere, which
could have been one of the possible cause of the

Write An Essay On The Marcellus Shale
1– Marcellus Shale:– The Marcellus shale is a Middle Devonian primary source rock in the
Appalachian basin as well as an unconventional reservoir rock.The Marcellus shale is produced
through the implementation of horizontal drilling and hydraulic fracture stimulation. The Marcellus
shale has been one of the most important developments in gas production over the past few years.
Having a good understanding of what this gigantic gas reservoir can do to shape the future of the
natural gas industry is vital to understanding today's U.S. economy. The Marcellus shale has rich
black organic shale with low density,and it is located in West Virginia, Pennsylvania, and New York.
In addition, small areas of Maryland, Kentucky, Tennessee,

Essay on New Albany Shale
Illinois Basin Structure
The Illinois Basin lies across Illinois, Indiana, and Kentucky, and it has a oval like structural
depression in southeastern Illinois. The Illinois Basin is classified as an intracratonic basin (Bois and
Pelet 1982). The Illinois Basin began as a rift complex which eventually failed, the New Madrid
fault is associated with this rifting (Hasenmueller and Comer 1994). The depositional thickness of
the New Albany Shale was strongly affected by the regional down–warping in southeastern Illinois
(Lineback 1980). The Illinois basin is separated from the Michigan basin by the Kankakee arch,
which is located primarily in Indiana (Nelson 1995). To the South East lies the Cincinnati arch
(Nelson 1995). In central and ... Show more content on Helpwriting.net ...
Genevieve Fault Zone (Hasenmueller and Comer 1994). During the Devonian while the New
Albany Shale was being deposited, the Sangamon Arch was active causing the New Albany Shale to
thin out (Hasenmueller and Comer 1994). The Media Anticline was also active during the time of
deposition, this can be seen by the thinning across the structure while there is no thinning on older
strata (Hasenmueller and Comer 1994). The Mount Carmel Fault is a normal fault that trends
northwest and has seismic data that indicates it reaches the basement (Hasenmueller and Comer
1994).
(Barrows and Cluff 1980)
Stratigraphy
The New Albany Shale is a body of rock in the Illinois Basin that is mostly shale that ranges from
brownish black shale that is organic rich to gray or greenish–gray organic poor shale (Linback
1980). There are thirteen main strata that comprise the New Albany shale and that includes the
Blocher Shale, the Sylamore Sandstone, The Selmier Shale, the Sweetland Creek Shale, the Grassy
Creek Shale, the Morgan Trail member, the Morgan Trail member, the Camp Run member, the
Clegg Creek member, the Saverton Shale, the Louisiana Limestone, The Horton Creek Shale, and
the Hannibal Shale (Lineback 1980). These sub groups that range lithologies of calcareous shale or
dolomitic (Lineback 1980).
The Blocher Shale is characterized by its calcareous and dolomitic black shales texture that grades

Essay Tetrapods
The early Devonian period is largely considered to be a world of a diverse array of lobe–finned fish,
including lungfish, coelacanths, and bony fish. Over the course of time, vertebrates made
evolutionary strides with provided them with the ability to travel on land. Coelacanths developed a
single boned shoulder girdle, lungfish developed paired fins, and sauripterus developed the major
structures on the arm (humerus, radius, and ulna). As these developments progressed and
environmental pressures were amounting in aquatic environments, vertebrates began to venture onto
land. Sometimes it was for short excursions, sometimes a bit longer. A major step in vertebrate
evolution was the advancement of the tetrapod, a vertebrate animal with ... Show more content on
Helpwriting.net ...
Many species are completely aquatic during the juvenile part of the lifecycle. For example, frogs
have to reproduce in water because amphibian eggs do not have the protection of the amniotic sac.
As a result, the adults must return to a water source to reproduce. As tadpoles grow into adults they
form limbs that allow them to walk on land. Because of the restriction to semi–aquatic environment,
the tetrapod structure of amphibians is not as diverse as the other classes of tetrapods. However,
there are groups that deviate from the norm by a lot. Caecilians are limbless amphibians. At first
glance they do not look like tetrapods but the lack of limbs is a derived secondary characteristic.
Their bodies have adapted for burrowing in the ground. Reptiles, the next tetrapods to emerge, were
a very successful version of amphibians. As opposed to amphibians, reptiles did not require water
for the reproduction process they produced shelled amniotic eggs to protect their embryos from the
environment. Due to the reduced dependence on water, reptiles were able to explore many new
environments and as a result their limbs evolved in a variety of ways. Crocdylotarsians developed a
"normal ankle" which swings to the side when walking, making walking slightly more efficient.
Dinosaurs developed a hole in their hip socket that allowed them to stand upright and to move
significantly faster. Another way some terrestrial reptiles

Waucoba Wash Quadrangle
Geologic History of Waucoba Wash Quadrangle, California
The Waucoba Wash Quadrangle, California cross section begins with the deposition of the Cambrian
layers such as the Campito Formation, Poleta Formation (upper and middle members and
undivided), Harkless Formation, Saline Valley Formation (lower and upper members), Mule Spring
Limestone, Monola Formation (lower and upper members), and the Bonanaza King dolomite
(dominantly limestone and undivided). These Cambrian rocks are followed by rock layers from the
Devonian period, thus meaning that an unconformity occurred between the layers. The Devonian
dolomite rock layers include the Hidden Valley dolomite and the Lost Burro Formation (cherty
dolomite). These are followed by the Mississippian ... Show more content on Helpwriting.net ...
One of the major things noticeable from the cross section is that quite a few of the rock layers are
over turned, where the older rock layers are above the newer rock layers. This is seen in the contact
between the Quartz Monzonite of Papoose Flat and the Campito Formation which is also a
disconformity. Next there is some fault zones separating the Camptio, Poleta, and Harkless
formations. We then see some more overturned layers with the contacts between Saline Spring
Valley Formation (lower and upper members) above the Mule Spring Formation along with some
inferred folding. With a normal fault separating the inferred folding event, we see where the
overturning occurs. In between the Cambrian layers we see Tertiary Basalt nonconformities also
being folded, thus with that we know that the folding event was more recent than the formation of
the Basalt. Next there is a large Basalt field with a spot of the Harkless formation. Again we see over
tuning as the Basalt field ends there are the Devonian and Mississippian rock Layers on top of the
basalt. Separating these overturned layers from the Harkless Formation and the Saline valley
Formation (upper member), which are not overturned, is a thrust fault. From this information, there
was a major stress event sometime after the Tertiary period causing the rock layers to fold and
overturn. And from this stress event and from the folding, normal and thrust faults are formed.
Finally we see that there were alluvial and landslide deposits from the Quaternary after the folding,
faulting, and over

Alycia Stigall's Research
Biodiversity is a necessity for every ecosystem to thrive in equilibrium. However, the balance
between species, predators, and prey can be disturbed by the most microscopic change. One of these
catalysts are invasive species: living organisms that are non–native to an ecosystem. Alycia Stigall's
research (2010) has been fundamental to finding why speciation declined during the late Devonian
biodiversity crisis. Potential causes of speciation include reproductive isolation and geographic
isolation, which is also known as vicariance. Stigall studied three different species of shallow
marine invertebrate organisms and determined their speciation by combining each species'
geography and phylogenetic backgrounds. Measurements of the biodiversity ... Show more content
on Helpwriting.net ...
For instance, the Itaipu Reservoir on the Paraná River in South America is a man–made cistern that
utilizes hydropower for the area in the form of dams and reservoirs. When the reservoir inundated
the Guaira Falls which served as an ecological filter separating most species, fish that had lived in
the lower part of the Paraná River gained access to the upper Paraná River (Vitule, 2012). In order to
quantify homogenization, Vitule employed Jaccard's coefficient which measures similarities
between species in the same community. From the data, he concluded that homogenization occurred
in the area not by the elimination of threatened species but by the unidirectional movement of fish.
More than half of the species in the upper Paraná Basin were distributed from the lower Paraná
Basin after the reservoir flooded. Thus, homogenization and consequent loss of biodiversity of the
Itaipu area was directly influenced by anthropogenic

Problem Set 3 Quiz
Bios101
Problem Set Three
1. (two points) A researcher is excavating a fossil bed from a Devonian reef, now fossilized in
Pennsylvania. She encounters many species that are new to science. a) Which species concept would
be most expedient and effective, in the process of collecting, naming, and describing what she finds?
Phylogenetic species concept would be the most expedient and effective process of collecting,
naming, and describing what she found. Phylogenetic relies on common ancestry and shared
evolutionary when defining a species.
b) Go online and research. Give at least three examples of actual species that were present in the
Devonian period. What is the point, if there IS any point, to naming and describing species that went
Why this business of collecting sperm from males she never met? Std error is shorthand for standard
error of the mean, in this case, mean survivorship of the ten groups of eggs fertilized by males in the
same category. Why did the researcher list it? Would the data be as credible without it?
The female was not allowed to choose whatever male she wanted because the category for each
won't be completed for the second part of the experiment. The researcher listed the Std error because
she wanted to ensure that the data was correct. She wanted us reader to know what the mean
survivorship of the ten groups of eggs that was fertilized by males in the same category.
c) Go online and research. Explain the good genes hypothesis. What is ich? Describe its life history.
The good genes hypothesis is the traits where females choose when selecting a mate that have
honest indicators whether the male's ability to pass on genes that will increase the survival or
reproductive success of her offspring. Ich is a type of an aquatic parasite that quickly attach
themselves on the outer layer of a fish's skin once they are born. Its life history is that they will feed
off it's host until it dies or when they are big enough to detach itself and reproduce.
5. (two points) Go to the following link and read the paper.

Werribee Geological Formations
The Werribee region illustrated to consist of different geological formations ranging from the
Ordovician period to the Holocene epoch period. Werribee Gorge State park had the oldest
formations with slate, shale, sandstone and Siltstone all from the Ordovician period. However, once
in the woodland area; medium to a coarse grain of Devonian and granite was also found. You Yangs
Regional Park had the second oldest formations as it consists of Coarse grained Devonian Granite,
sediments of marine sands from the Pliocene period. However, it also consisted of Non–marine sand
outwash from the most recent Alluvium period. Alkaline Olivine Basalt from the Palaeocene period
is noted to be along the Pentland Hills. The hills at Rowsley are known to be built up with younger
formations these are known to consist of Oligocene tertiary sediments and Pliocene Alluvium plains
which lie in between the Basalt ridges. In addition to the Volcanic sediments, tertiary sediments
from the Oligocene period is also seen in this region. Therefore, the soil formations in this region
have influenced these sites to be mainly used for grazing. ... Show more content on Helpwriting.net
...
Therefore, it promotes the growth of different plant species. However, due to the characteristics of
this region, it means that pest species such as the Ulex Eroupaeus L flourishes. The land is
considerably flat along river banks and this particular plant species flourishes in areas where there is
a lack of rainfall; this region is known to receive less annual rainfall compared to the major
populated towns it's surrounded

Big 5 Mass Extinction Events In Research
Throughout the lifetime of the Earth, there have been various scientists who have hypothesized
various extinction events. The following essay will cover the five major extinction events, otherwise
known as the "Big 5 Mass Extinction Events". According to Wikipedia (2016), a mass extinction is
"a widespread and rapid decrease in the amount of life on Earth. Such an event is identified by a
sharp change in the diversity and abundance of multicellular organisms".
The first major extinction event is said to have been the Ordovician–Silurian mass extinction, 443
million years ago, which occurred during the end of the Ordovician period, and the start of the
Silurian period (bbc.co.uk, 2014). This is the third largest mass extinction in the Earth's history, and
there were two "peak" dying times during this period, separated my hundreds of thousands of years.
The Ordovician is characterised by sea life, so creatures such as brachiopods, graptolites and
trilobite populations were severely diminished. An ice age is said to be responsible for the death
(endangerdspeciesinternational.org, 2011).
The Late Devonian mass extinction is well–known for having one of the most drastic extinction
rates. During this extinction period, which spans over a few million years, ... Show more content on
Helpwriting.net ...
However, along with the dinosaurs there were many other creatures such as pterosaurs, ammonites
and many flowering plants that were wiped out as well. It is said that a combination of dropping sea
levels and flood basalt eruptions were one of the causes (Murcia, 2015). The proverbial final nail in
the coffin was a meteorite strike, near the Yucatan peninsula in Mexico, which caused the most
significant damage. This extinction event is also known as the K/T extinction (bbc.co.uk,

Devonian Period
At the start of the Devonian Period, about 419.2 million years ago, our planet was undergoing major
change. The union of the paleo–continents of Laurentia and Baltica (made up of what is now parts
of modern day North America, northern Europe, Russia, and Greenland) occurred near the
beginning of the Devonian Period and formed a supercontinent that straddled the Equator. That
landmass has been called Laurussia, or Euramerica.
There was a great deal of red sediment created when North America collided with Europe. The
unique rocks formed from these sediments were first studied in Devon, England, giving the
Devonian period it's name.
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 ... Show more
content on Helpwriting.net ...
The first forests appeared near the close of the Devonian. Towards the end of the Devonian period,
many major extinction events occurred. One was the Taghanic Event, which killed off many
goniatites, corals, and brachiopods. It's still debated what the cause of these events were, but some
think it was a meteorite. Others say it was because of the sea level lowering or changes in
atmospheric carbon dioxide. Up to 70 percent of invertebrate species died, but terrestrial plants and
animals weren't affected much.
The rocks that formed during Devonian time are known as the Devonian System. Some include
shale, limestone, and granite. A common index fossil is Mucrospirifer, a now extinct brachiopod, or
marine invertebrate.
This period holds significance for two reasons. For one, many countries use the rock that existed in
the Devonian period today for building materials and abrasive materials. Additionally, oil and
natural gas, which we rely on heavily for energy, are produced from Devonian rocks. The second
reason is the formation of Euramerica, which eventually led to the supercontinent,

Wandilla Terrane Formation
INTRODUCTION
The New England Fold Belt (NEFB) of eastern Australia is composed of variably deformed
terranes, going in age from Early Palaeozoic to Late Triassic. These different terranes are for the
most part understood to reflect an alternate tectonic component, or different orogenic events.
However, is mostly believed to have developed within an extensively convergent plate margin
setting (Day et al., 1978, 1983; Henderson, 1980; Fergusson et al. 1988).
Exposures that reveal the complete subduction complex rocks can be seen in the Wandilla and
Shoalwater formation of the Gladstone–Yeppoon area of central Queensland.
The aim of this short review is to present the character and interpretation of the Wandilla terrane in
the New England Fold ... Show more content on Helpwriting.net ...
1988, 1990). The presences of fossils in its formation are nearly not present. However, the presence
of large number of sedimentary ooids and oval–shaped crinoids' fossils implied its age to be Early
Carboniferous (Fleming et al. 1975). Figure 2. Show the Structural map of the Wandilla(Wt) and
Shoalwater terranes (St) in the Rockhampton–Gladstone district. Image is source from (fergusson,
Henderson and Leitch, 1990).
Detailed studies by Fergusson et al. (1988, 1990a, b) has documented three stages of deformation
for the structure of the Wandilla terrane. These are summarized as D1, D2, and D3 deformation. For
this review, a quick summary of these deformation are as follow.
 D1 developed extensive mélange of lenticular features in which platter particles of greywacke and
tuff emerge in a mudstone matrix with scaly fabrics (S1 ).
 D2 Developed complete cleavage (S2 ) with related folds (F2 ) as show in figure 3.
 D3 Structures are conjugate network of strike– slip faults that are steeply dipping developed by
NE– SW aligned compressing and related fault breccias and

What Are Their Veertebrate Characteristics
A. Fish & Early Amphibians
1) Ostracoderm. What are their characteristics? Did they all look the same? Do they possess the
chordate characteristics? Vertebrate characteristics?
The ostracoderms once were considered the oldest and most primitive of the known chordates
(Gregory, 1935).
Their fins were small, and they lacked lateral fins, but did have medial fins. They had permanently
open mouths.
They have small size – none longer than 15 cm
They used ciliated motion to move food, ostracoderms used their muscular gill pouch to create a
suction that pulled in small and slow moving prey.
All ostracoderm have similar characteristic and they depict vertebrate characteristics.
2) What did conodonts look like? What characteristics did they share ... Show more content on
Helpwriting.net ...
Compare mouth position (subterminal, terminal), teeth, jaws (amphistylic vs hyostylic), & fin shape.
Cladoselache
Cladoselache had a short, rounded snout, a mouth located at the front of the head long jaws attached
to the cranium under the snout and behind the eye, cladodont teeth, and a stout spine in front of each
dorsal fin and has crescent–shaped tail fin, with an upper lobe about the same size as the lower
Hybodus
Complete with two dorsal fins that would have helped it steer with precision.
They had two different types of teeth, suggesting a wide diet. The sharper teeth would have been
used to catch slippery prey, while the flatter teeth probably helped them crush shelled creatures.
They had a bony blade on their dorsal fin that probably served a defensive function
Neoselachii
They have wide spread pectoral fins and the upward curved tail fin to provide lift
They have crescent–shaped mouths are set on the underside of the body.
They several rows of sharp, triangular teeth

5) Find a fish with ganoid scales and give its' genus. Is it an Actinopterygian? If so, to which branch
(Holostei, Chondrostei, or Teleostei) does it belong? Did early Chondrostean look like extant
sturgeon? Give

Exam Three Study Guide
Chapter 11
The first Paleozoic orogeny to occur in the Cordilleran mobile belt was the: | c. Antler | |
Extensive cratonic black shales were deposited during what two periods? | d. Late Devonian–Early
Mississippian | |
The main economic deposit of a cyclothem is: | a. coal | |
During the Late Kaskaskia (Cratonic Sequence 3), what type of deposition predominated on the
craton? | e. carbonates | |
Which orogeny was not part of the closing of the Iapetus Ocean | b. Antler | |
Rhythmically repetitive sedimentary sequences of alternating marine and terrestrial sediments are: |
c. cyclothems | |
During which period did extensive continental glaciation of the Gondwana continent occur? | ...
| a. rift valleys | | | b. dikes | | | c. great quantities of poorly sorted nonmarine detrital sandstones | | | d.
sills | | |
The first Mesozoic orogeny in the Cordilleran region was the: | | b. Nevadan | | | d. Sonoma | |
The Mesozoic tectonic history of the North American Cordilleran region is very complex and
involves: | a. oceanic–continent convergence | | | b. terrane accretion | |
The formation or complex responsible for the spectacular scenery of the Painted Desert and Petrified
Forest is the: | c. Chinle | |
The Sierra Nevada, Southern California, Idaho, and Coast Range batholiths formed as a result of
which orogeny? | d. Nevadan | |
The first major seaway to flood North America was the: | d. Sundance | |
The orogeny responsible for the present–day Rocky Mountains is the: | c. Laramide | | The Jurassic
formation or complex famous for dinosaur fossils that Marietta College's dinosaur program is

famous for digging in each summer and will be going to visit in Utah during May to collect more
dinosaurs from is the: | a. Morrison | |
The breakup of Pangaea began with initial Triassic rifting between which two continental
landmasses? | d. Laurasia and Gondwana | |
The time of greatest post–Paleozoic inundation of the craton (by transgressive seas) occurred during

Summary: The Five Major Extinction Events In History
In the course of Earth's history, there have been five major extinction events: the Ordovician–
Silurian, Late Devonian, Permian–Triassic, Triassic–Jurassic, and Cretaceous–Paleogene extinction
events. Now, according to Pulitzer Prize–winning author Elizabeth Kolbert, we are entering another
one that is caused by a single species: ours. Human beings have decimated the rainforest, hunted
animals like the great auk to extinction, pumped billions of tons of pollution into our atmosphere
and oceans, and almost completely reassembled the biosphere. Even more frighteningly, these facts
come from 2014, and in the four years since The Sixth Extinction's initial release, we haven't slowed
down a bit. Kolbert closes her book with a call to action, ... Show more content on Helpwriting.net
...
440–450 million years ago, the Ordovician and Silurian extinction events began, killing 60–70% of
all the species alive at that time. These events, often combined and referred to as the Ordovician–
Silurian event, were the second largest of the five major extinction events, as measured by the
percentage of genera (57%) that disappeared. The next major event was a little under a hundred
million years later, at the end of the Frasnian Age. This event, referred to as the Late Devonian
extinction, resulted in the elimination of 70% of all species and lasted for an estimated 20 million
years. 252 million years ago, the most catastrophic extinction of all occurred, the Permian–Triassic
event. It was estimated to have killed 90–96% of all species, including 96% of all marine species
and 70% of all land species; the recovery period before vertebrates evolved lasted 30 million years.
Only 50 million years later, the Triassic–Jurassic extinction event came to pass, killing 70–75% of
all the species that had only so recently developed. Finally, there was the Cretaceous–Paleogene
extinction event, which began about 66 million years ago. This is possibly the most famous
extinction, as it is the one responsible for killing the dinosaurs, as well as 75% of the other existing
species. We have been safely in a recovery period for the last 66

The Quaternary Period and Other Periods
Cambrian:
This period started 540 million years ago and ended 500 million years ago.
There was a very mild climate. The supercontinent Rodinia began to break into smaller parts, or
continents. Lots of glaciation occurred so many animal families went extinct.
All phyla develop during this time period. Many marine animals, shell–fish, echinoderms, and some
of the earliest fish appear.
Lots of glaciation occurred wiping out many animal families marking the end of the Cambrian
period.
Ordovician:
Many primitive plants appeared on land and some of the first corals. Primitive fish and fungi also
make an appearance. High sea levels occur at fist but lower as global cooling, glaciation and
volcanism increase.
Plants, fungi and primitive fish are on land during this time period.
Glaciation marked the end of the Ordovician period.
Silurian:
The first vascular plants appear on land (plants with water–conducting tissue). High seas spread
worldwide, brachiopods, crinoids and corals also make an appearance.
The first fish with jaws appeared during this time period along with insects, centipedes and
millipedes.
Glaciation marked the end of the Silurian period.
Devonian:
Swampy forests on land and fish and land

The Extinction Of Animals During The Devonian Period
During the Devonian period, most of the oceans were filled with stromatoporoids, brachiopods and
corals. The Devonian period gave rises to some of the first tetrapods, amphibians, sharks, insects
and boney fish. The first real land plants were also formed, giving rise to the first forest. The first
plants were only about a foot tall and had no roots or leaves. By the late Devonian, plants had
formed roots and leaves. The late Devonian Extinction was about 359 million years ago, and about
20 percent of all animal families and about 70 percent of all animal species were killed. Marine
species and freshwater species such as ammonites, conodonts, benthic foraminifera suffered the
most extinction, whereas terrestrial species were hardly affected.

Why The Coalbed Methane
More countries in the world extract the methane from coal beds and today it is established in a
number of countries throughout the world, including the USA, Australia, China, India and Canada.
The advantage of the coal is almost pure carbon and its reservoir character is fundamentally
different to conventional gas plays.
The Coalbed methane refers to methane that is produced in association with coal, and CBM reserves
are located wherever large deposits of coal are found. CBM is formed through organic
decomposition, and it adheres to the many surfaces of the coal until it is released through natural or
man–made processes. This "unconventional" energy resource has both similar and unique challenges
to those in conventional oil and gas production.

Isotope Anomalies Across The Frasnian Famennian Extinction...
Isotope anomalies across the Frasnian–Famennian extinction boundary:
Implications for resolving Late Devonian mysteries
Abstract
The cause of the Late Devonian mass extinction near the Frasnian–Famennian boundary remains
uncertain. Anomalies of stable isotope values have been observed at the Frasnian–Famennian
boundary commonly, indicating the abrupt changes of environments during the crisis. These changes
include marine anoxia possibly triggered by land plant evolutions, global cooling, and global
warming probably induced by multiple bolide impacts. In this study, the variations of isotope
compositions are summarized to investigate the possible major causes of F–F mass extinction.
Introduction
The transition from the Frasnian to ... Show more content on Helpwriting.net ...
Verzer and others (1998) complied 87Sr/86Sr values during the Devonian. They found that the
values increased from the end of Middle Devonian to Famennian, and a spike of 87Sr/86Sr occurred
around the Frasnian–Famennian boundary (Figure 1). Heavy strontium isotope (87Sr) commonly
occurs in continental rocks (Hurley, 1968). Thus, maximum values at the boundary indicate higher
intensity of continental weathering and enhanced delivery of terrestrial influx into marine.
Increased terrestrial influx could have served as nutrients for algae and plankton and stimulated high
bioproductivity at surface water. The oxygen in surface water would have been over–consumed by
respiration and decaying of marine organisms, which was thought to trigger marine anoxia (Algeo et
al., 1995). In this process, lighter isotope of carbon was preferentially taken up by aquatic organisms
and therefore removed from the system, producing heavy carbon anomalies (Wang et al., 1996).
Consequently, positive excursions in δ13C values were observed across the F–F boundary (Figure
2). In addition, higher bioproductivity would bring about elevated burial rate of organic carbon
(Wang et al., 1996; Chen et al., 2002)
As reported by Wang and others (1996), the positive δ13C excursions coincide with positive shifts
of δ34S around the F–F boundary (Figure 2), providing direct evidence for

Bryophytes: The Beginning Of The Permian Period
The common land plants are thought to have originated 450–500 million years ago from a group of
freshwater green algae called charophytes (Domozych). These algae emerged on land and thus
spawned the first plants, bryophytes. Bryophytes are non–vascular plants who first appeared 354–
409 million years ago in the Devonian period, and are only found on land (Evolution). Since they
lived on land, they had little support and relied on their cells' turgor pressure to keep them upright
(Evolution). Turgor pressure is the force that is generated from fluid pushing against the cell wall
which allows the plant to stand upright (Friedl). Bryophytes include three divisions: mosses,
hornworts, and liverworts (Bryophyte). Bryophytes do not have roots ... Show more content on
Helpwriting.net ...
In fact, there are at least 250,000 known species of angiosperms leaving them the most diverse plant
group (Evolution). Angiosperms have three features that set them apart from gymnosperms: flowers,
double fertilization, and embryos with an ovarian wall (Evolution). Angiosperms' flowers are what
carries the male and female reproductive systems (Evolution). Double fertilization is when "two
male gametes (sperm nuclei) are released from the pollen tube into the ovule. One of these sperm
nuclei fuses with an egg cell in a similar way to gymnosperms. The second nucleus (which
degenerates in most gymnosperms) fertilizes other cells in the ovule called polar nuclei. Most
commonly, two polar nuclei fuse with the sperm nucleus to form a triploid endosperm nucleus. The
tissue that forms from this fusion is called endosperm, which in most angiosperms provides
nutrients for the developing embryo" (Evolution). Finally, after embryo fertilization has occurred,
the ovarian wall that protects the embryo will become fruit

Devonian Rocks
Melbourne has a bedrock of Middle Paleozoic age which is included within the Devonian and
Silurian periods (354–441 million years prior). These rocks are overlain in wide zones which also
include much more youthful rocks, and were generally part of the Tertiary and Quaternary ages (2–
65 mya). Rocks of Early Silurian (441 mya) were discovered to be the most established within the
bedrock. Particular in the outcrops located in the north–east around Warrandyte (Anderson Creek
Formation), and on the west side of Melbourne more specifically the Maribyrnong Valley around
Keilor (Springfield Formation). Fossils found within these developments are very unique. Rocks
located east of Keilor and south of Warrandyte were discovered to be more youthful, with different
ages from Late Silurian (418 mya) in the Melbourne Formation (city region) to Early Devonian (384
mya) at the Humevale Formation (Lilydale).
These Paleozoic rocks are steeply plunging sandstones and siltstones, with a little event of limestone
at Lilydale – the Early Devonian Lilydale Limestone. The Silurian rocks were stored in profound
water, while the Devonian rocks, which are exceptionally fossiliferous, appear to have been stored
in shallower water. These Silurian and Devonian rocks were folded into a progression of anticlines
The first scene helped shape the Keilor and Werribee Plains on the west side of Melbourne due
broad sheets of basalt magma. The second stage included volcanoes toward the north of Melbourne.
These expelled streams that filled the valleys of the Moonee Ponds, Merri and Darebin brooks. Due
to these volcanic eruptions form Hayes Hill near Mernda, magma streams flowed down towards the
Darebin Creek and ancestral Merri Creek valleys and into the Yarra Valley at Fairfield and further
down that valley and onto the Yarra delta and as far as Spencer Street

Organic Petrology and Maturation of the Bakken Formation...
This document describes in detail the organic petrology and maturation of the Bakken Formation
located in the Williston Basin. This report is organized into five sections. Section I will introduce the
Bakken Formation in reference with the Williston Basin. It will also address sedimentary and
structural aspects of the Bakken Formation. Section II outlines the processes that formed the Bakken
Formation that occurred during the Devonian/Mississippian age. Section III will summarize organic
components and influence within the Bakken Formation. Furthermore Section IV will address the
nature of inorganic constinuents that influence the Bakken Formation. Section V will discuss
production history and current production of oil and gas found within ... Show more content on
Helpwriting.net ...
The middle member of the Bakken Formation is a calcareous sandstone that formed offshore in a
regressional environment that formed with a rapid lowering of sea level.
One of the primary structures in the Bakken Formation is the Nesson Anticline which lies in the
northwestern part of North Dakota (Schieber, 2001). The Nesson Anticline in North Dakota trends
North for 176 km. The Williston Basin as a whole is a sedimentary basin that is located west on the
North American craton that dates Paleozoic in age, making the Bakken Formation an intracratonic
formation. The Williston Basin is located in North Dakota, South Dakota, Montana, Saskatchewan,
and Manitoba. However, the Bakken Formation is not the only formation within the Williston Basin,
however it will be the only formation discussed in this paper.
II. Formation of the Bakken
The Bakken Formation is a Late Devonian to Early Mississippian formation within the Williston
Basin as seen below in Figure 1. To understand the process that formed the Bakken it is necessary to
understand the formation of the Williston Basin as a whole. Figure 1 represents the stratigraphy of
the Williston Basin. The Bakken Source Rock can be seen between the Devonian and the
Mississippian contacts in this diagram. This figure also shows that the Williston Basin began
subsiding in the Late Cambrian and continued to subside since then (Peterson, 1995). Also seen in
Figure 1 is the Nesson Anicline that

The Late Devonian Mass Extinction Period

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The Late Devonian Mass Extinction Period