The Dinosaur Extinction Mystery By Michael Bento Essay

The Dinosaur Extinction Mystery By Michael Bento Essay
The Dinosaur Extinction Mystery
By Michael Bento
EES 112–25; Fall 2016
One of the great unsolved mysteries in our planet's history is the extinction of dinosaurs. We know
they existed through fossil record and with the help of some geological evidence that supports
various theories, some stronger than others, we start to narrow down the possible culprit. Dinosaurs
evolved and existed for about 180 million years during the Mesozoic era. The Mesozoic is divided
into three periods: the Triassic, Jurassic, and Cretaceous periods. They thrived in the Triassic and
Jurassic periods, but declined in the Cretaceous period. The Triassic period lasted about 245 to 213
million years ago where dinosaurs first evolved and all the continents were still connected, better
known as Pangaea. The Jurassic period continued to the beginning of the Cretaceous period 144
million years ago. At this time, the continents started to break apart and dinosaurs increased in
number. The Cretaceous period was the last period in the Mesozoic era and at the end of the period,
some 65 million years ago, dinosaurs disappeared known as the K–T extinction event. We know this
because fossils were found throughout the Mesozoic era, but not in Cenozoic era rock layers. Birds
and other reptiles such as alligators survived into the Cenozoic era, better known as the Age of
Mammals (Barrett & Raul, 2001).
The first dinosaur skeletons were found in England around the 1820's and by 1889, there were
samples
... Get more on HelpWriting.net ...

The Cretaceous-Tertiary Period
The time frame that makes up the Cretaceous–Tertiary period is an area in which causes much
controversy and mystery among people. Although research shows us that there was a rapid change
in Earth's climate during this era, there are many different theories that seem to show other sides of
the story. During this time there was a global climate change from warm Mesozoic to a cooler
Cenozoic (Fluteau, 2014). Although research tells us that there was a substantial change in Earth's
climate during this time, it is difficult to grasp what really happened because the data seems to point
in many different directions based on the hypotheses. Although both "thought groups" intrinsic
gradualists and extrinsic catastrophists show solid hypotheses, the ... Show more content on
Helpwriting.net ...
"Intrinsic gradualists" are scientists that believe that the cause of the Cretaceous–Tertiary extinction
was mainly from Earth's natural process that gradually took place over several million years. The
"Intrinsic gradualist" had two main hypotheses that are strongly supported till this day. The first
hypothesis is volcanism. Studies have suggested that towards the end of the Cretaceous period, there
was an increase in volcanic activity (Keller, 2014). This increase in volcanic activity could have
blown enough ash and soot to block out sunlight, thus lowering the global climate. The magma
arising from these volcanic eruptions are high in iridium, which are found throughout Earth in the
Cretaceous–Tertiary stratigraphic boundary (Bajpai, 2000). Around this time of high volcanism, a
mantle superplume deposited great amounts of basalt, which flooded into the Deccan Plateau, to
form large lava beds, which are now called the Deccan Traps (Keller, 2014). The Deccan Traps
cover about 200,000 miles, and at such large scale, these traps also dispersed tremendous amounts
of dust and ash in the atmosphere (Keller, 2014). The second "intrinsic" hypothesis revolves around
plate tectonics. During the Cretaceous–Tertiary time frame, the continental plates were drifting apart
and experiencing large amounts of tectonic activity. As a result, large bodies of water, such as the
Interior Seaway in North America, experienced regression (Nordt, 2003). This regression of the sea
resulted in the increase in humidity, which was associated with the middle to high latitude cooling
over several million years (Nordt, 2003). These "intrinsic" hypotheses support one another, because
volcanism, in many cases, is a result of plate

Cretaceous-Rat Extinction Research Paper
The cretaceous–tertiary (KT) boundary extinction happened approximately sixty five million years
ago. Sixty to eighty percent of all living species became extinct at this boundary (Raup 1988). The
KT extinction was indeed a mass extinction event. Mass extinctions are periods in Earth's history
when extremely large numbers of species die out simultaneously or within a limited time frame. The
most severe mass extinction ever occurred at the end of the Permian period when 96% of all species
died out. The K–T mass extinction obliterated almost all the large vertebrates on Earth, on land, at
sea, and in the air (all dinosaurs, plesiosaurs, mosasaurs, and pterosaurs) suddenly became extinct at
the end of the Cretaceous Period. At the same time, most ... Show more content on Helpwriting.net
...
There are a lot of theories about why the K–T extinction occurred, but a widely accepted theory was
proposed in 1980 by a physicist named Luis Alvarez and his son Walter Alvarez who was a
geologist. the theory is that an asteroid 4–9 miles (6–15 km) in diameter hit the Earth about 65
million years ago, creating the Chicxulub crater at the tip of Mexico's Yucatán Peninsula. The crater
is more than 110 miles in diameter and 12 miles in depth. It is one of the largest confirmed impact
structures on Earth; The impact would have penetrated the Earth's crust, scattering dust and debris
into the atmosphere, and causing huge fires, tsunamis, severe storms with highly acidic rain ,
seismic activity, and perhaps even volcanic activity . The impact could have caused chemical
changes in the Earth's atmosphere, increasing concentrations of sulfuric acid, nitric acid, and
fluoride compounds. The heat from the impact's blast wave would have incinerated all the life forms
in its path. The evidence for the impact was first discovered by Walter Alvarez and some of his
colleagues. They found that rocks laid down precisely at the K–T boundary contain extraordinary
amounts of the metal iridium. The dating is precise, and the iridium layer has been identified in
more than one hundred places around the Earth. Where the boundary is in marine sediments, the
iridium occurs in a layer just above the last Cretaceous microfossils, and the sediments above it
contain Paleocene microfossils from the earliest part of the Cenozoic. Iridium is much rarer than
gold on Earth, yet in the K–T boundary clay iridium is usually twice as abundant as gold, sometimes
more than that. The same high ratio is found in meteorites. The Alvarez group therefore suggested
that iridium was scattered worldwide from a cloud of debris that formed as an asteroid struck
somewhere on Earth. Shocked quartz was

What Killed The Dinosaurs Analysis
Since the 1980s the most popular theory for why dinosaurs became extinct was because of a meteor,
but many people are skeptical of whether or not the meteor was the only factor in the extinction of
the dinosaurs. In Stephen Brusatte's "What Killed the Dinosaurs," Dr. Brusatte talks about how the
mystery of the extinction of the dinosaurs was a hug influence on his life and caused him to become
what he is today. As a teenager Brusatte had a chance to talk to Walter Alvarez, the man who
proposed the idea of a meteor being the cause for the extinction of the dinosaurs. Alvarez was able
to come up with this hypothesis by examining the clay band between the Cretaceous period and the
Paleogene period. The Cretaceous period was a time when the Earth had a surplus amount of
dinosaurs and the Paleogene period was the time period directly after the Cretaceous period where
dinosaurs had become extinct. When Alvarez studied the clay band he had discovered that the band
was saturated in iridium which is an element common on meteors and asteroids. This led him to
believe that a meteor may have led to the downfall of the dinosaurs. ... Show more content on
Helpwriting.net ...
Brusatte did more research on this topic when he was a graduate student when his colleague Richard
Butler proposed the idea of both of them together looking at the changes that dinosaurs went
through during the ten to fifteen million year before they became extinct. I thought this was very
interesting as a reader to see how Brusatte, someone who focuses on early life of dinosaurs and birds
combine with someone like Butler who works in the more mathematical side of evolutionary trends.
They were able to join forces and research about a single topic in order to discover something they
both want to know about. Together they did their research by examining dinosaur diversity trends by
using morphological disparity. They learned that most dinosaurs had a steady disparity and only
herbivore dinosaurs like horned and duck billed had a declining

The Mesozoic Era
Introduction
The Mesozoic Era began around 250 million years ago and ended 65 million years ago. It is divided
into three different periods, The Triassic, The Jurassic and The Cretaceous. In the Mesozoic Era
Earth was extraordinaly different from what it is now. The climate was humid and tropical, the sea
levels were constantly changing and even the shape of the Earth 's continents were different (Benson
et al, 2010). The land was dominant by the dinosaurs but the oceans were populated by more rich
and diverse marine reptiles. There were more than a dozen different groups of marine reptiles in the
Mesozoic era, these groups contained pelagic and coastal predators and coastal herbivores. The three
main predators of the oceans were the ... Show more content on Helpwriting.net ...
During the Late Triassic period they reached their highest diversity, they became more advanced and
specalized, making them one of the top Marine predators. Ichthyosaurs over time evolved to have
streamlined, fish–shaped bodies and large heads. They also evolved to have thicker bodies and a
thicker backbone which meant they swam more with a convergent motion (Callway, 1997). They
had the largest eyeballs (up to 264mm in diameter), of all vertebrates which were supported by a
ring of sclerotic bones, these eyes were adapted to help them find prey in low light environments
(Motani, 2009). Ichthyosaurus also had large ear bones, scientists believe this was an adaptation that
allowed them to locate their prey by listening for their arrival through the water . This adapation was
also a useful way for them to listen for predators that may be approaching (Fisher et al, 2016). The
most distinguishable feature of their body plan was the presence of the caudal fin and the dorsal fin
which was formed of stiff tissue, not bone. The first whole fossil of an Ichytosaur was discovered
200 years ago by Mary Anning on the Jurassic coast of Dorset at Lyme Regis. Mary Annnings
brother, Joseph found the skull of an Ichthyosaur in 1811 between the cliffs at Lyme Regis and
Charmouth but failed to find the rest of it. Mary went out found the remainings of this fossil a year
later, she found the rest of the fossil at Lyme Regis. This fossils skull was around 1 meters long and
the whole

The Cretaceous-Paleogene Boundary Essay
The Cretaceous–Paleogene Mass Extinction
Wil Creasy Student Number: 20921355
The Cretaceous–Paleogene boundary (K–Pg boundary) was host to one of the three largest mass
extinctions in the past 500 million years. Evidence suggests it was the result of a large asteroid
impact approximately 65.5 million years ago in Chicxulub, Mexico; hence why the crater it formed
was named the Chicxulub crater. The crater was approximately 180 kilometres in diameter and was
believed to have led to the extinction of the dinosaurs amongst many other life forms including
marine plankton (calcareous nannofossils and planktonic foraminifera) (Schulte et al., 2010).
Furthermore, it had a number of impacts on the atmosphere and environment including the creation
of sulfuric acid rain and stratospheric dust cloud formations. ... Show more content on
Helpwriting.net ...
The deposit included a millimeter thick red clay layer that includes an iridium anomaly, ejecta
spherules and nickel rich spinel (Schulte et al., 2010). The age of the deposit coincides with the time
of the mass extinction. It is coincidences such as this that have led scientists to believe that the mass
extinction and the Chicxulub impact are related.
The Yucatan–6 borehole provided significant evidence to suggest that there was an impact event that
took place. The composition of the melt rock was believed to have been the result of an impact
rather than volcanic events (Kring and Boynton, 1992). What allowed scientists to confirm this, was
the surviving clasts of target rock they discovered within the melt, were similar to that seen In the
Manicouagan impact crater. (Kring, 2007) Furthermore, these clasts were said to be composed of
shocked quarts and feldspar, which are indicative of an impact

The Cook Inlet Basin : Location And Extent
Yetter, Drew J., Cook Inlet Basin
Location and Extent: The Cook Inlet Basin is located in the south central part of Alaska, and
stretches roughly 180 miles from the Gulf of Alaska to Anchorage. (Figure 1) This basin includes
Susitna and Copper River basins in the north and the Shelikov Straight to the southwest. The
watershed of this inlet covers around 100,000 km2 in southern Alaska, east of the Aleutian
Mountain Range, receiving water from four main tributaries, the Knit, Little Susitna, Susitna, and
Matanuska Rivers. The Cook Inlet is extremely important to the economy of Alaska as it provides a
navigable passage to the port of Anchorage in its northern end.
Stratigraphy: The Augustine–Seldovia arch, which is oriented east–west, transverse to the main
structural trend of the basin, separates the forearc basin into two depocenters. (ADNR 2006). The
northern depocenter in upper Cook Inlet is dominated by roughly 25,000 feet of Cenezoic strata. The
southern depocenter in lower Cook Inlet and Shelikof Strait contains a thinner Cenezoic section
superimposed on top of 36,000 feet of Mesozoic strata.
Tertiary deformation the Cook Inlet basin started between Eocene and early Oligocene time.
Deformation in the upper Cook Inlet is resulted in folds, faults, and eroded horst blocks. The
deformation was a result of transpressional forces. (Figure 3) As a result, adjacent grabens filled
with alluvial deposits and continued to deform until late Miocene to Holocene time.

Horseshoe Crabs
For years, directors have made several movies insinuating what life would be like if dinosaurs were
living on Earth today, such as what dinosaurs would look like and how they would act.
Archeologists, paleontologists, and other researchers have proven the existence of dinosaurs. Fossil,
preserved remains, evidence dates back to over 200 million years ago ("Dinosaur"). Each fossil, or
remains, gives identifying information about the creature that once lived. Experts have revealed
dinosaurs to be in the reptile category. Nevertheless, not all reptiles are dinosaurs. However, aquatic,
land, and air life in the Paleozoic, Mesozoic eras in which dinosaurs lived and the Cenozoic era, also
known as the present time, animals share many similarities. ... Show more content on
Helpwriting.net ...
The transition started with the Triassic period bringing on animals such as dinosaurs. A familiar
animal, the Crocodilians also referred to as crocodiles first arrived during the Triassic period along
with turtles. The most common period throughout the Mesozoic era is the Jurassic. The Jurassic
period is known for movies such as Jurassic Park and Jurassic World, but it is where reptiles began
to dominate the world until the Cretaceous period. Crocodiles are closely related to birds. The
Archaeopteryx, one of the first birds, contained similar characteristics of nonavian dinosaurs such as
teeth, feathers, an extended vertebral column to form a long tail, and a big brain ("Dinosaurs").
During the Cretaceous period, vegetation flourished, large reptiles, dinosaurs, began extinction, and
accurate birds, seen today, thrived. Both crocodiles and birds live on Earth and are the closest thing
to dinosaurs anyone will

A Evolution Of The Late Jurassic
Charophytes are green algae that have been found in fresh water to moderately brackish water
environments. Their gyrogonites are minute oval or round calcareous bodies that represent the
calcified parts of the oogonium i. e. the female reproductive organs. Most of the plant consists of
organic matter that decays shortly after death. Under some circumstances the stems and branches of
the plant become calcified and are also preserved in the geologic record. In the absence of the
planktonic and benthonic foraminifers, ostracodes and charophytes becomes valuable
biostratigraphic tool for geologic analysis and interpretation (Carbonel, 1988; Colin & Lethiers,
1988; Martin–Closas & Schudack, 1996, Schudack, 2000 & 2006). Moreover the charophytes have
been the focus of intensive work since the early 1960, since it was hope to obtain valuable
information on the dating, biostratigraphic and paleoecology of the strata (Schudack, 2002 & 2004).
The present study attempts a comprehensive biostratigraphic evolution of the Late Jurassic – Early
Cretaceous sequence at Messak escarpment based on the stratigraphic distribution of the
charophytes species as this type of microfossils have not been studied before in Libya as well as the
study area has never been studied for charophytes beforehand. On the basis of the stratigraphic
distribution of charophytes it is possible to subdivide the Late Jurassic – Early Cretaceous sequence
into four assemblage zones. These are described in ascending

Tyrant Lizard King: Tyrannosaurs Rex
Tyrannosaurs Rex, better known as the T–Rex, which means Tyrant lizard king lived during the late
Cretaceous period, about 85 million to 65 million years ago. They were 40 feet long and 20 feet tall
and weighed up to 7.5 tons. They were strictly carnivores and used their very sharp teeth to eat other
dinosaurs. Fossils were discovered in Western North America and the skull of a T– Rex alone
measured up to 1.5m(5ft) long. The also have the record of having the largest tooth of any
carnivorous dinosaur found to this day, which is around 30cm (12in) long. When the T–Rex hits
around the age of 14 its body size would increase rapidly, putting on around 600kg (1300Ib) a year
over the next 4 years. Another dinosaur that lived during the Cretaceous

Petroleum Geology Of The Sarir Essay
PETROLEUM GEOLOGY OF THE SARIR "C" FIELD, SIRTE BASIN,LIBYA
Complied by: 9606617
MSC PETROLEUM GEOSCIENCE, UNIVERSITY OF MANCHESTER
PETROLEUM GEOLOGIC OF THE SARIR "C" FIELD
IN THE SIRTE BASIN, LIBYA
1. INTRODUCTION The Sarir 'C' oil field is a super–giant hydrocarbon field, located near the
south–eastern margin of the late Cretaceous – Tertiary Sirte Basin of Libya. The field is 56km long,
40km wide, and covers an area of about 378km2.
The Sarir "C" field is a higly prolific hydrocarbon producing field in North Africa (figure1) with an
estimated ultimate recovery of about 6.5bbl of oil in place (Carmalt et. al; 1986) It was discovered
in Southern Cyrenaica in 1961, forms part of three complex fields(fig3), and has other significant
fields like the Amal, Defa, Augila, Hateiba, Messla, Bu Atifel, lying in the same Sirte basin.
1.1 Location and Geological Setting of the Field.
LOCATION and GEOLOGIC SETTINGS The study field is located in the Sirte Basin. This Basin,
located in the north central extension of Libya, covers an area of about 500,000km2, between
latitudes 270N–330N and 160E and 220E. It is ranked 13th among the world's major hydrocarbon
provinces and contains the major hydrocarbon producing fields in Libya.
The Sarir "C" oil field is located on the western arm of the Calanscio Sand Sea in the southern
Cyrenaica. The Basin is dominated by the Tertiary Sirte–Zleten petroleum system which is
subdivided into four units, which developed from

Dinosaur Decay
Dinosaurs roamed the earth many million years ago while roaming parts of Maryland for many of
their history here on earth. There were many species that were predominantly found in this location.
Around twelve species of dinosaur like animals can be traced back to these parts of Maryland.
Dinosaurs wandered in this area from Late Triassic to Late Cretaceous periods. Maryland had a
distinct climate changes during these periods. Once it was tropical and had volcanoes and changed
to warm and shallow temperatures. Because of these temperatures we were able to find
preservations of these few dinosaur fossils. These fossils resisted decaying and were found in low
lying areas and were buried in alluvial sediments. If they were not destroyed by other

Why Do Dinosaurs Really Lived In Antarctica?
The first dinosaur fossil was found by Reverend Plot, in 1676, at the time it was believed to belong
to a "giant" but was probably from a dinosaur although a report of this find was finally published by
R. Brookes almost 100 years later in 1763. Theories suggest that it was a Megalosaurus dinosaur. It
was after this time that scientist more specifically, paleontologist became interested in these giants.
Even with today's advances in technology, scientists are not sure about the lifespan of some
dinosaurs, some scientists believe that they might have lived for 200 years, up to present time. Apart
from that a lot of people think that dinosaurs only lived in some parts of the world, but that is wrong
and fossils have been found that indicate, dinosaurs lived in Antarctica.
Where ... Show more content on Helpwriting.net ...
The second type is called "Thyreophorans" also lived during the early Jurassic to Cretaceous
periods, were plant eaters, walked on four legs and had armored plates on their body. The last but
not least group was called "Marginocephalians" referring the ones living in the Cretaceous era, plant
eaters that had horns or thick skulls (Col, 2015). If you move further into dinosaur types, they are
divided into Theropods (meat eaters, powerful legs, short arms), Sauropods (long necks, long tails,
walked on four feet), Stegosaurus (slow, bony plates or spikes), Ankylosauria (bony armors on their
back), Ceratopsian (walked on four legs, had three horns as well as a bony frill), Ornithopoda
(walked and ran on two feet), Pachycephalosauria (had thick skulls and walked on the back legs).
Dinosaurs can be divided into different kinds by name, by species classification, also by what they
ate (Gilbert,

The Paleogene Period: A Genetic Analysis
Long before the first species of human were alive, mammals were the ones occupying the earth.
This specific period of geological time, called the Paleogene period, dated back to 66 million years
ago and ended 24 million years ago; further dividing the Paleogene period, there is the Paleocene,
Eocene, and Oligocene epochs. Each epoch is categorized based on their distinct differences, mainly
in geography, climate, plants, and animals. To find out why scientists split the Paleogene into four
epochs, we will analyze the differences in ecological conditions in each epoch and find the effect
each epoch had on specific types of early primates. The Paleocene is the oldest epoch of the
Paleogene period, dating from 66 to 56 million years ago. The Paleocene is special because it started
with the Cretaceous–Paleogene boundary (K–T boundary) and ended with the Paleocene–Eocene
Thermal Maximum (PETM). The K–T boundary marked the end of the Cretaceous period and the ...
Show more content on Helpwriting.net ...
The epoch is considered one of the essential time because of the major transition earth went through;
the development of tropical forests and grasslands that expanded globally. Apidiums and
aegyptopithecus lived during this epoch. Apidiums are around the size of a squirrel and their dental
formulae suggest that they were frugivores and possibly seed eaters. There is also a significant
difference in size between male and female apidiums, which suggest a strong sexual dimorphism.
Apidiums' limb remains also show that they excel in leaping and jumping. Aegyptopithecus share a
similar dental formula as apidiums which means they possibly have the same diet. According to R.
Jurmain and other authors (1979), aegyptopithecus "was likely a short–limbed, heavily muscled,
slow–moving arboreal quadruped" and "was long viewed as the best candidate from the Fayum to
have given rise to Old World monkeys, apes, and

The Peninsular Terrane And Jurassic Island Arc Complex
The Peninsular terrane is a Triassic to Jurassic island–arc complex that was accreted to the North
American craton by the Early Cretaceous (Detterman and Reed, 1980; Jones et al., 1987; Ridgway
et al., 2002; Trop et al., 2002, 2005; Clift et al., 2005). The terrane includes mafic to andesitic flows
and volcaniclastic rocks, limestone, and mudstone. These rocks structurally overlie and are intruded
by Jurassic plutonic rocks of the Talkeetna arc (Reed and Lanphere, 1973; Reed et al., 1983; Rioux
et al., 2010). The plutonic rocks include gabbroic to granitic compositions, but are dominated by
quartz diorite and tonalite rocks (Detterman and Reed, 1980; Reed et al., 1983).
The Togiak terrane, located west of the Peninsular terrane, is an ... Show more content on
Helpwriting.net ...
1; Reed and Lanphere, 1973; Wal–lace and Engebretson, 1984; Moll–Stalcup, 1994; Bundtzen and
Miller, 1997; Wilson et al., 2006; Amato et al., 2007). The intrusive rocks include granite,
granodiorite, syenite, mon–zonite, and diorite. Limited gabbroic rocks have been mapped. The
volcanic rocks are mostly of rhyolitic, dacitic, and basaltic compositions.
Several NE–striking crustal–scale faults have been recog–nized in southwestern Alaska (Fig. 1;
Detterman et al., 1976; Beikman, 1980). The Lake Clark fault extends from Lake Clark northeast
into the Alaska–Aleutian Range batholith (Detterman et al., 1976). Based on offsets measured on
aeromagnetic anomaly maps, Haeussler and Saltus (2005) es–timated that there has been
approximately 26 km of dextral offset along the Lake Clark fault since the Eocene. Ivanhoe (1962)
suggested that approximately 10 km of offset has oc–curred since the Tertiary, based on offsets of
geologic units. The Pebble district is located southwest of the mapped extent of the Lake Clark fault.
The fault has not been recognized west of Lake Clark (Detterman and Reed, 1973, 1980; Plafker et
al., 1975; Koehler, 2010).
The Mulchatna fault is parallel to the Lake Clark fault (Beikman, 1980). In general, the fault
coincides with the boundary between the Kuskokwim and the Kahiltna basins and is interpreted to
have significant dextral strike–slip and/or dip–slip displacement since the Late Cretaceous to

The Geology Of The Peninsular Terrane
out along a ~400–km–long, NE–striking belt within the Kahiltna basin (Fig. 1). They are mainly
flysch deposits inter–preted to have been derived primarily from the igneous rocks of the Peninsular
terrane to the southeast, with local contri–butions from the Triassic Chilikadrotna Greenstones to the
northwest (Wallace et al., 1989; Wilson et al., 2006).
The Peninsular terrane is a Triassic to Jurassic island–arc complex that was accreted to the North
American craton by the Early Cretaceous (Detterman and Reed, 1980; Jones et al., 1987; Ridgway
et al., 2002; Trop et al., 2002, 2005; Clift et al., 2005). The terrane includes mafic to andesitic flows
and volcaniclastic rocks, limestone, and mudstone. These rocks structurally overlie and are intruded
by Jurassic plutonic rocks of the Talkeetna arc (Reed and Lanphere, 1973; Reed et al., 1983; Rioux
et al., 2010). The plutonic rocks include gabbroic to granitic compositions, but are dominated by
quartz diorite and tonalite rocks (Detterman and Reed, 1980; Reed et al., 1983).
The Togiak terrane, located west of the Peninsular terrane, is an island–arc complex that contains
Late Triassic to Early Cretaceous basaltic to dacitic volcanic and volcaniclastic rocks and graywacke
(Decker et al., 1994). These rocks were ac–creted to the North American craton during the middle to
late Early Cretaceous (Box, 1985).
The Peninsular and Togiak terranes are separated by the Farewell terrane (Fig. 1) that contains a
Lower Paleozoic through Lower

The Origins Of The Dinosaur Myth
For over a century, paleontologists have been collecting abundant dinosaur fossils from the Western
Interior of North America, with many of these fossils found in rocks dating back to the final stages
of the Cretaceous Period. Only recently, however, have we learned that most of these dinosaurs
existed on a "lost continent" today referred to as 'Laramidia". (Switek, 2010)
Two new species of horned dinosaurs have been found in the Grand Staircase–Escalante National
Monument in Southern Utah. The bigger of the two new dinosaurs, Utahceratops gettyi, had a skull
2.3 meter (around 7 feet) long. The first part of the name combines the origin of the find and
ceratops, Greek for "horned face". The second part of the name honors Mike Getty, the paleontology

Dinosaurs: The Juurassic Period
Dinosaurs lived over 65 million years ago, part of their existence was in pangea which broke up 200
million years ago. There were three periods. The triassic period, the jurassic period, and the
cretaceous period.
The triassic period was the first period of the mesozoic era and happened between 251 and 199
million years ago. The triassic period was when other animals started to form that could walk on
land and not in water.
The jurassic period was the second period of the mesozoic era and happened between 199 and 145
million years ago. The jurassic period is when the gigantic continent ( pangea ) split apart and into
the other continents. This period is when the herbivores (plant eaters) came to existence. oceans full
of fish, squid, and

Fossil Lagerstätten
A Fossil–Lagerstätten is an undisturbed fossil accumulation in which fossils are exceptionally
preserved. There are two types of fossil lagerstätten: Concentration Lagerstätten (Konzentrat–
Lagerstätten) and Conservation Lagerstätten (Konservat–Lagerstätten). Concentration Lagerstätten
are deposits of an immense number of preserved fossils, whereas Conservation Lagerstätten are the
preservation of fossils in terms of quality rather than quantity (Nudds and Selden, 2008). There
might be few fossils in the rock strata, however, the preservation of these are exemplary. There are
many outcropping areas on Earth in which fossils are preserved like this. One example of a group of
strata that has retained fossils in this way is the Crato Formation.
Location
The Crato formation, Brazil, is a geological rock formation ... Show more content on
Helpwriting.net ...
(2016), the Araripe group would belong to the Aptian–Albian Stages in the Lower Cretaceous
Period.
The Crato Formation lithologies were most likely deposited when there was a marine transgression;
which is what the Cretaceous period is renowned for (Hu et al. 2012). The build–up of laminated
limestones and different lithologies in the stratigraphic column could suggest that it was a lagoon
depositional environment (Martill and Frey, 1998).
Fossil Assemblage
The most prominent fossils in the Crato Formation are the insects that are preserved. One example
of an insect that has been recently found is the Araripenymphes seldeni (as seen in figure 3), an
extinct species of lacewing (Myskowiak et al., 2016). The taphonomic classification of A.seldini is:
Nymphidae Family Neuroptera Order, and Insecta Class (Myskowiak et al., 2016). This particular
species shows sexual dimorphism, a difference in characteristics beyond the sexual organs
(Clarkson, 1998). In particular, differences in the wing colouration and wing lengths (Myskowiak et
al.,

Cretaceous Mass Extinction
The Cretaceous mass extinction had two theories on how and why it happened through the impact
hypothesis. The first one was suggested that an asteroid collided with Earth 65 million years ago.
Luis Alvarez and his son, Walter Alvarez found "high levels of the rare metal iridium" in the layers
of the Earth during the periods of the Cretaceous and Tertiary located in Italy. Their proof is that it
was the cause of extinction by an asteroid the size of 10 kilometers. The second impact hypothesis
was from a crater that was found buried off the coast of Yucatan, Mexico. Due to the material that
was thrown from the crater into the air, plant life could not receive sunlight to survive. The same
goes for animals as the atmosphere was filled with dangerous

Mesozoic Vertebrates
Mesozoic vertebrates of Texas have received less attention than Paleozoic. In the early 1900s E. C.
Case collected and reported amphibians and reptiles found in Triassic sediments along the eastern
edge of the High Plains, and Sankar Chatterjee of Texas Tech University has also made important
discoveries there. Notable are skeletons of phytosaurs. These aquatic reptiles, up to thirty feet in
length, had elongated snouts armed with thick, sharply pointed teeth. Their habits were probably
much like those of modern crocodiles. Some lightly armored forms were not unlike crocodiles in
appearance, except for their long, hook–nosed snouts, but some armored types of phytosaurs may
have looked almost like arthropods. Through work centered at the University of Texas at Austin,
parts of the Trans–Pecos region have yielded important fossils of Cretaceous reptiles, among them
enormous crocodiles and the largest known pterosaur. Much of Central Texas probably contains
bones of Cretaceous vertebrates, but the land is so heavily vegetated that discoveries are few.
However, remains of dinosaurs, plesiosaurs, and even primitive mammals have been found and are
preserved at the University of Texas and Southern Methodist University. Fossil vertebrates,
especially mammals, of the middle to late Tertiary and Pleistocene ages abound in Texas. Much of
the fossil history of horses, camels, rhinoceroses, and other kinds of both living and ... Show more
content on Helpwriting.net ...
Schultz, West Texas State University, Canyon; Sankar Chatterjee, Texas Tech University, Lubbock;
Walter W. Dalquest, Midwestern State University, Wichita Falls; Bob Slaughter and Lewis Jacobs,
Southern Methodist University, Dallas; Arthur H. Harris, University of Texas at El Paso; and Wann
Langston, Jr., John A. Wilson, and Ernest L. Lundelius, Jr., University of Texas at

Does The Cretaceous Period Affect The K-T Mass Extinction?
The Cretaceous period is a period of time within the Mesozoic Era lasting from 146 million years
ago to 65.5 million years ago. It is one of three periods in the Mesozoic Era along with the Triassic
and Jurassic periods. The Cretaceous period is well known for the amount of dinosaurs it had, and
the event that put an end to the dinosaurs reign, the K–T mass extinction. During the K–T mass
extinction, a huge asteroid hit earth and caused tons of dust to infiltrate the air. Only a small portion
of dinosaurs died on impact Instead, the dust blocked out sunlight which caused plants to die.
Without plants, many dinosaurs did not have a food source, so the died out. Carnivore dinosaurs,
such as the Tyrannosaurus Rex, survived a little longer

The Triassic Era
The Mesozoic Era contains three geologic time periods including the Triassic Period ,from 252
million to 200 million years ago. The Triassic period was named in 1834 by the German geologist
Friedrich August Von Alberti (1795–1878). It was originally named the "Trias". It got its name
because this period of geologic time is represented by a three–part division of rock types in
Germany . It began 252 million years ago, at the close of the Permian Period, and ended 201 million
years ago. Jurassic Period, from about 200 million to 145 million years ago. During the Jurassic
Period, the supercontinent Pangaea split apart. The Jurassic was a golden age for the large
herbivorous dinosaurs known as the sauropods–Camarasaurus, Apatosaurus, Diplodocus,

The Cretaceous Period Essay
The Cretaceous Period
The Cretaceous period was the last and longest part of the Mesozoic Era. This period of time lasted
around 79 million years! It lasted from the end of the Jurassic Period's extinction (145 million years
ago) to the beginning of the Paleogene Period (65.5 million years ago.) In this time, the earth's
continents were not in the same shape as they are today. Pangea, the supercontinent, was still
drifting apart from itself. The ocean was still separating Northern Laurasia and Southern Gondwana,
however the North and South Atlantic were still closed. The Central Atlantic had already started to
open up during the Jurassic Period. By the middle of the Cretaceous Period, the ocean levels had
risen and the placement of the continents were similar to what they are today. South America and
Africa had gotten their shapes by this time, but India and Asia did not join yet, nor did Australia
separate from Antarctica.
The climate ... Show more content on Helpwriting.net ...
The end of this period happens to be one of the most famous extinctions. This was the extinction
when all of the dinosaurs died out, except for the birds. About 65.5 million years ago, nearly all
large vertebrates and many tropical invertebrates became extinct. So, what caused this mass
extinction? Scientists still do not have a definite answer, but they do have two hypotheses'. These
hypothesis are that an extraterrestrial impact, such as an asteroid or comet, or a massive bout of
volcanism put an end to it. Either of these things would've choked the skies with debris, which
would've blocked the suns energy. The block in the suns area would've caused a lot of harm to
photosynthesis, therefore many animals would not have a food source to supply them with the
necessary nutrients. By the end of the Cretaceous period, all large and small ruling reptiles, except
the crocodile became extinct. Whatever the explanation to this extinction was, it resulted in the
Cretaceous Period

The Permian-Triassic Period
Mesozoic Era:
The dinosaurs and the mammals appeared during the triassic period,Roughly 225 million years ago.
The dinosaurs went extinct 65 million years ago. The Mesozoic Era lasted about 180 million years,
and is divided into three periods, the Triassic, the Jurassic, and the Cretaceous.
The Mesozoic Era is an interval of geological time from about 252 to 66 million years ago. It is also
called the Age of Reptiles, a phrase introduced by the 19th century paleontologist Gideon Mantell .
The Permian–Triassic boundary, at the start of the Mesozoic, is defined relative to a particular
section of sediment in Meishan, China, where a type of extinct, eel–like creature known as a
conodont first appeared, according to the International commission on stratigraphy. Life and climate
The Mesozoic Era he Mesozoic Era began roughly around the time of the end–Permian extinction,
which wiped out 96 percent of marine life and 70 percent of all terrestrial species on the planet. Life
slowly rebounded, eventually giving way to a flourishing diversity of animals, from massive lizards
to monstrous dinosaurs.
The Triassic period from 252 million to 200 million years ago, saw the rise of reptiles and the first
dinosaurs, the Jurassic period , from about 200 million to 145 million years ago, ushered in birds
and ... Show more content on Helpwriting.net ...
The current locations of the continents and their modern–day inhabitants, including humans, can be
traced to this period. The era began on a big down note, catching the tail end of the Cretaceous–
Paleogene extinction event at the close of the Cretaceous period that wiped out the remaining non–
avian dinosaurs. The global climate of the early portion of the Cenozoic Period was much warmer
than it is today, and the overall climate of the Earth was much more consistent regardless of
proximity to the

Cretaceous-Triassic Extinction Research Paper
An extinction event (also known as a mass extinction or biotic crisis) is a widespread and rapid
decrease in the amount of life on Earth. It occurs when the rate of extinction increases with respect
to the rate of speciation. Extinction occurs at an uneven rate.
The most recent and debatably best–known, the Cretaceous–Paleogene extinction event, which
occurred approximately 66 million years ago (Ma), was a large–scale mass extinction of animal and
plant species in a geologically short period of time.
It is now generally believed that the K–Pg extinction was triggered by a massive comet or asteroid
impact 66 million years ago and its catastrophic effects on the global environment, including a
lingering impact winter that made it impossible for plants and plankton to carry out photosynthesis.
The fact ... Show more content on Helpwriting.net ...
The sea floor is also completely recycled every 200 million years by the on–going process of plate
tectonics and seafloor spreading, leaving no useful indications beneath the ocean. The former group
includes one or more large bolide impact events, increased volcanism, and sudden release of
methane from the sea floor, either due to dissociation of methane hydrate deposits or metabolism of
organic carbon deposits by methanogenic microbes. The latter group includes sea level change,
increasing anoxia, and increasing aridity. Any hypothesis about the cause must explain the
selectivity of the event, which affected organisms with calcium carbonate skeletons most severely;
the long period (4 to 6 million years) before recovery started, and the minimal extent of biological
mineralization (despite inorganic carbonates being deposited) once the recovery

Northern Carnarvon Basin
During the early to middle Palaeozoic, the northwest orientation was the main deformation features
in Australia and Northern Carnarvon Basin. In Northern Carnarvon Basin, several sub–basins and
Plateaus are separated by northwest oriented faults and basement highs. Cape Range Fracture Zone
(CRFZ) separates the west side of Exmouth Plateau, the Long Island Fault System separates the
southern boundary of Barrow Sub–Basin and Sultan Nose uplift separates the Barrow from Dumpier
Sub–Basin (DAIM, 1998). During middle Palaeozoic, basin started extending to northeast direction
and deformation and structures orientation shifted from the Northwest to the Northeast trend. These
northeast structural features were inherited to the deformation pattern throughout Mesozoic.
Intermittent rifting of Australia ... Show more content on Helpwriting.net ...
Another rifting phase started in the early Jurassic around Pliensbachian or Toarcian (Chongzhi et al.,
2013; Geoscience, 2014; Tindale, Newell, Keall, & Smith, 1998). Exmouth, Barrow, Dampier and
Beagle Sub–basins were created until Middle Jurassic (He, 2002; Tortopoglu, 2015) and oceanic
crust was laid down to form the Argo Abyssal Plain in Late Jurassic around 164–160 Ma during the
Callovian to Oxfordian then followed by the Gascoyne and Cuvier Abyssal Plain in Early
Cretaceous around 125 Ma (Fullerton, Sager, & Handschumacher, 1989; Müller, Mihut, & Baldwin,
1998). Passive margin was established in North West Shelf. Rifting phase of the basin transformed
into sagging phase post breakup thermal subsidence when Gondwana breakup took place during
Valanginian early Cretaceous around 134Ma. During the Campanian late Cretaceous, rifting along
the Australian southern margin triggered the basin inversions and wrench reactivation of basin
structures on NW Shelf. These movements arose the Barrow Island above sea level and formed
Novara, Resolution and Exmouth Plateau Arch in Barrow, Dampier Sub–Basins and Investigator
Sub–Basin (Figure 1) (Longley et al., 2002; Sinhabaedya,

Formation Of The Kufra Basin
The NSAS area has been subjected to intensive geological studies by several workers (Ball, 1927;
Sandford, 1935; Knetsch and Yallouze, 1955; Ibrahim, 1956; Said, 1962; Hume, 1965; Ambroggi,
1966; Ezzat, 1974; Pallas, 1978; Amer et al., 1981; Klitzsch and Wycisk, 1987, 1999; El Ramly,
1983; Klitzsch et al., 1987; Hesse et al., 1987; Schandelmeier et al., 1987a; Wycisk, 1987a, 1990,
1993,1994; E1 Gaby and Greiling, 1988; Klitzsch, 1989, 1994; Said, 1990; Hermina, 1990; Klitzsch
and Squyres, 1990; Klitzsch and Semtner, 1993; Mansour et al., 1993; Thorweihe and
Schandelmeier, 1993; Issawi, 1999). The two major units of the aquifer, the Kufra Basin (Libya,
northeastern Chad and northwestern Sudan) and the Dakhla Basin (Egypt) (Fig. 1), have undergone
different geological developments. Formation of the Kufra Basin began in the Early Paleozoic, and
was complete at the end of the Lower Cretaceous. The Dakhla Basin was presumably formed at the
beginning of the Cretaceous (at least its southern portion).
In addition to the geological developments described above, the aquifer area also comprises the
upper Nile Platform in Egypt, as well as the Northern Sudan Platform in Sudan. These are, however,
areas of minor importance for groundwater resources. The NSAS changes gradually from
continental sandy facies in the southern regions, to intercalations of sandstones and clays of
alternating continental and shallow marine facies in the central regions, to mainly marine facies in
the

Cretaceous Time Period Research Paper
Cretaceous Period
Everyone knows about the dinosaurs and how they went extinct. This was one of the major events
that took place in the Cretaceous Time Period. The Cretaceous Period was the longest and last of
three time periods in the Mesozoic Era. This time period lasted from about 144 million years ago
until about million years ago (about 79 million years), and over that 79 million years the earth
changed dramatically. Way back in the Cretaceous all of earth's land was together in one big super
continent we call Pangea. The average temperature was warmer throughout earth then in comparison
to present day. The north and south poles were still colder than places along the equator even back
then. But still, the earth was warmer than it is now with excessive rains in some places and little to
no rain in deserts. Maybe the most notable ... Show more content on Helpwriting.net ...
Approximately 65.5 million years ago most of the planet's land animals and many of the animals in
the seas went extinct. As far as we know this was caused by a massive asteroid colliding with earth
in what is now the Chicxulub crater in the Yucatan peninsula. The collision is thought to have
caused tsunamis and clouds of hot dust were sent into the atmosphere and probably started huge
wild fires. Many of the animals that survived all of that would later die when the sun was blocked
out for months or possibly years causing temperatures to drop and plants to die.
I would not like to have lived in the Cretaceous Period. For one thing pretty much all of the planet's
land area was in a much hotter climate than we live in which I don't think I would like. Another
reason is the fact that the land and plants were different in a way that may have been interesting to
see but not so great to live in. And of course the obvious reason that there were still dinosaurs which
would probably be pretty dangerous and make life

Cretaceous Mass Extinction
The Cretaceous mass extinction is the most well–known case of meteorite impact on the earth, but it
certainly is not the only one. It is merely the most well–known. Due to the impact, debris entered
earth's atmosphere and caused the plant life of the time to die off due to the lack of sunlight to
survive. This made food much more scarce for the species that were dominant at the time. The
competition was simply too much for them, and as the plant life died out, so did the herbivores and
then the carnivores died out as well. Not only the land was impacted, however, the sea life was
affected heavily by this impact as well. The lack of sunlight caused the oceans to become colder,
causing the habitats of many marine animals to be drastically altered

Wrangel-St. Elias National Park
Three research studies conducted at and including Wrangel–St. Elias National Park show evidence
that dinosaurs once roamed the area, marine invertebrate fossils are the most abundant and varied
fossil resources in several national parks in Alaska and there are troubling levels of harmful mercury
in fish found at the park. In a study published in Cretaceous Research and conducted in October
2012 by Anthony R. Fiorillo, Thomas L. Adams and Yoshitsugu Kobayashi, evidence of dinosaurs
was based on the finding of an unnamed nonmarine sedimentary package of rocks. Found in the
Wrangellia Terrane and considered to be Cretaceous age, the rocks are light colored with medium
grey shales and indicate a bounty of horsetails, ferns and gymnosperm wood. ... Show more content
on Helpwriting.net ...
Wrangell–St Elias is one in four Alaskan national parks that tested positive for mercury. In some
cases the levels exceeded the State of Alaska's human consumption levels of mercury for women
and children. The test was part of a multi–year U.S. geological survey and study of fish in high
elevation lakes and streams. Mercury was found in all fish and can be harmful to other fish, wildlife,
humans etc. The mercury was found in fish in Copper, Tanada, and Summit Lakes. Consuming high
amounts of mercury can damage developing brains in babies and

Permian and Cretaceous Mass Extinctions Essay
Assess the different hypotheses put forward for the mass extinctions at the end of the Permian and
Cretaceous (KT) Periods.
A mass extinction is an event in which at least 25–75% of species in the global environment are
eradicated in a short period of time. Where as a regional extinction event is when the extinction is
confined to a specific zone. Five mass extinctions have occurred throughout time, two of the most
well known of these are the Permian and Cretaceous extinction events.
There are several hypotheses that are used to explain the causes of mass extinctions. Climate
change, the warming or cooling of global environments over a short period of time, can lead to other
occurrences. Shifts in climate can cause extinction by ... Show more content on Helpwriting.net ...
A crater, the Bedout crater, in Australia has been discovered. A bolide impact would have lead to
mass death of marine and terrestrial organisms. The force of the impact could have released methane
from stored organic matter and large earthquakes. These earthquakes would have triggered the
volcanism in the Siberian traps, leading to the release of large amounts of CO2 and sulfur dioxide.
These gases combined with methane previously released would have created a noxious atmosphere,
combined with climate change that killed a large scale of life.
It is most likely that a simultaneous occurrence of the different global environmental changes was
responsible for ending the Permian period, and the lives of 96% of species. Each environmental
issue is a major geological event, and amplified the other events, leading to catastrophic
environmental situation, in which barely any life could survive.
The Cretaceous – Tertiary mass extinction, commonly referred to as the KT extinction, occurred 65
million years ago. As the most recant extinction event it is more easily studied as more evidence has
been preserved than for the earlier extinctions. This extinction is the most commonly known, as it is
the extinction of the dinosaurs, but the smallest scale mass extinction with only 76% of species
dying out.
Evidence for catastrophism at the KT boundary can be found in a layer of greenish

The Cretaceous Er The Last And Longest Segment Of The...
According to a live science, an article written by Mary Bagley, "The Cretaceous Period was the last
and longest segment of the Mesozoic Era. It lasted approximately 79 million years, from the minor
extinction event that closed the Jurassic Period about 145.5 million years ago to the Cretaceous–
Paleogene extinction event dated at 65.5 million years ago"(Mary Bagley, LS). In the cretaceous
period, the continent of Pangea was still breaking away from itself, forming what we now know as
the seven world continents. In the many eras of dinosaurs, the cretaceous era was responsible for
evolving some, but not all the dinosaurs from full land dinosaurs to some who were able to live both
on land and in water, semi–aquatic carnivorous dinosaurs. This era had produced some of the
dinosaurs that maybe us non– paleontologist are more familiar with like the all mighty
tyrannosaurus rex or the long neck. Well let me tell you, there were a lot more dinosaurs than just
those two. Although the tyrannosaurs rex was an enormous dinosaur, a bigger dinosaur was
discovered in 1912, the Spinosaurus. This discovery would change peoples, kids, and
paleontologists view on which dinosaur was bigger than the other. This semi–aquatic dinosaur,
Spinosaurus, was much larger than the T–rex due to its sail like backbones that stuck out of its back.
Furthermore, spinosaurus had a huge advantage that the tyrannosaurus–rex did not.
A Paleontologists job is to study their dinosaur discovery, and to tell us

Cretaceous-Paleogene Boundary Essay
The Cretaceous–Paleogene boundary that occurred around 65 million years ago marks one of the
three largest mass extinctions in the past 500 million years. The hypotheses of Cretaceous–Tertiary
boundary impact on Yucatán Peninsula, Mexico shows evidence in the Gulf of Mexico of turbidity
currents, and giant waves occurring because of the impact. There is also other evidence that impact
ejecta were distributed all over the world. The mineral that was ejected during this impact was
iridium. Iridium is a mineral that is commonly used to indicate a rock layer from the K–T boundary.
Iridium is only found naturally on extraterrestrial bodies. In addition to Iridium, shocked quartz is
used to indicate the K–T boundary. Shocked quartz is unique and ... Show more content on
Helpwriting.net ...
The four controls for a turbiditie sequence to form are tectonic activity, climate, sedimentary
processes, and sea–level fluctuations. The mass of the bolide that impacted the Yucatan Peninsula
would have been large enough to irritate the plates, and possibly catalyze their movements. The
suggested size of the bolide is around 180 kilometers. The climate of the time can be closer
examined by checking the paleontology of rock layers found before and after the K–T boundary.
Sedimentary processes and sea–level fluctuations could have taken a huge turn, due to the fact that
an unexpected large extraterrestrial body crashed into the Yucatan Peninsula. It is also suggested by
geoscientists that a tsunami about 50 to 100 meters high hit the coast of Texas, which resulted in an
unconformity near Brazos River, Texas. The two major end members of a turbidite are coarse–
grained to sand–rich and then fine–grained to mud–rich. These two end members are important
because they are used in order to examine submarine fans. Submarine fans can be geological clues
as to what was going on in a particular layer of

Human Culture Research Paper
The journey of prehistoric human culture on the Texas coast begins with how hunting and gathering
populations adapted to the opportunities and limitations of their shoreline and nearby prairie
environments. All the while using limited technology strengthened by first–hand knowledge about
the location and seasonal availability of important subsistence resources within their homeland.
Before my bioregion is explored, its best that I depict the history of the state that I live that spreads
across the millennia. When European explorers and colonists first arrived in the region, beginning in
the 1500s, the indigenous coastal peoples practiced a mix of subsistence economies which included
rigorous fishing in the shoreline bays and lagoons, ... Show more content on Helpwriting.net ...
The coastal population density was moderately high, and people spent much of the annual cycle
living in large shoreline fishing camps that housed several hundred people during peak fishing
seasons. The coastline as we see it today is, from a geologic perspective, a very recent phenomenon
that dates back only about 3,000 years. In fact, prior to around 8,000 B.C., the area of the modern
shoreline was high and dry, with the Gulf coast far to the east of its present position. This is because,
in earlier millennia, global sea level was as much as 300 feet lower, with much of the world's water
supply inaccessible in vast continental ice sheets and montane glaciers that were far more extensive
than those of modern times. The Pleistocene era, or Ice Age, had markedly lower global
temperatures than those of historical times. The final cold phase of the Pleistocene was around
20,000 years ago, after which rising global temperatures caused the continental ice sheets and
mountain glaciers to begin a gradual melting process, with the result that sea level began to rise
rapidly over the next 10,000 years (Hester, 1995).
As sea level rose, shorelines around the world moved progressively father inland. By 8,000 B.C. the
sea had inundated major river valleys along the Texas

The Cretaceous-Tertiary Extinction
The Cretaceous–Tertiary extinction or K–T extinction, which marks the Late Cretaceous, is a
massive and large–scale extinction of animal and plant species that occurred over a short period of
time 66 million years ago. The fossils of non–avian dinosaurs (the Group of birds) found almost
only below the K–T boundary, paleontologists mostly estimate that the dinosaurs were extinguished
just before, or during the event. Scientific theories explain the extinctions of K–T by one or more
catastrophic events, such as massive asteroid impacts, and increased volcanic activity, however, the
volcanic activity appearing to be anterior. The dating of several impact craters and that of rocks
resulting from massive volcanic activity in the Deccan traps coincide

Triassic Era Timeline
The Mesozoic Era spanned over 252 to 66 million years ago. This era is also known as the Age of
Reptiles. The Mesozoic Era consisted of three geological periods, the Triassic, Jurassic, and the
Cretaceous periods. The first period of the Mesozoic Era is the Triassic. The Triassic Period spanned
over roughly 252 million years to 201 million years ago. The first portion of the Triassic Period
a.k.a. the Early Triassic Period was before the continents had even broke apart from the large mass
called Pangaea. During this time most of the land was desert due to a mass extinction prior time,
where more than 90 percent of the inhabitants died off. The second portion of the Triassic Period is
the Middle Triassic Period. During this time Pangaea began to break apart and life began to flourish,
many sea creatures began to recover, such as algae and corals, and on land there vast amounts of
pine forests. The late Triassic the third and final portion of the Triassic Period is the boom of
reptilian evolution, with countless heat spells and moderate precipitation. During this time there was
another mass extinction call the Triassic–Jurassic extinction. ... Show more content on
Helpwriting.net ...
The Jurassic period consisted of 3 major epochs, the first being the Early Jurassic. During the first
epoch it was very humid resulting in most of the land mass to be tropical. Also began the major fight
for the top of the food chain and the first crocodiles evolved, causing most of the larger amphibians
to near extinction. The next epoch was the peak for the reptilian family, due to the abundant
predators that had come to be and the large herds of other dinosaurs. The last epoch of the Jurassic
Period wasn't very eventful. Most of the epoch consisted of the ocean rising, introducing more
diversification to the new legion of

Dinosaurs Are Awesome
If I had a time machine, I would want to go to a very famous time 67 million years ago. Although no
humans were living during that time, I still want to see how different earth was during that time so I
could confirm and add to the overall knowledge about the dinosaurs. The Cretaceous time period
was the last time period in which dinosaurs are seen. This time period spanned from 144 million
years ago (mya) to 66 mya; right after the Jurassic time period and before the Tertiary. This is a time
when dinosaurs were at their height with many thousands of different species known or yet to be
identified. Our earliest ancestors were small rodent–like mammals that lived during this time and
gradually evolved into the many different types of mammals we see today. The dinosaurs though,
would become small reptiles such as the lizards we see today after one of the greatest known
extinctions of all times–the K–T Extinction also known as the extinction of the dinosaurs. In this
time, I would see many giant dinosaurs such as the T–rex. These dinosaurs would be competing for
their own survival and their children's survival very roughly by killing other dinosaurs who get too
close to their nests or them. During this time, I would be wondering how did these giant creatures 30
feet tall die and have us puny mammals take their place as the dominant species? I would then
recount that thanks to a combination of a massive asteroid hitting earth, mammals, deadly diseases,
volcanoes, flowering

Essay about Examining the Cretaceous: Paleogene Extinction...
Examining the Cretaceous–Paleogene extinction event Over 98% of all organisms that have lived on
Earth are now extinct. A mass extinction event occurs when a large number of species die out within
a small time frame (relative to the age of Earth). Mass extinctions are intensively studied for both
cause and effect, as there is usually room for debate regarding catalysts that precede the extinction
and the massive influx of new biological species that follows. There have been five major mass
extinctions, dubbed the "Big Five," that have wiped out at least 50% of the species living at those
times. The most well known mass extinction of the Big Five, with the decimation of every species
of non–avian dinosaur, is the Cretaceous–Paleogene ... Show more content on Helpwriting.net ...
This final blow would have sent earth into a nuclear winter. According to this theory, dust caused by
the asteroid collision disrupted plant growth by blocking out the sunlight needed for photosynthesis
for nearly a year. A chain reaction occurred as plants died off, so did the herbivores relying on the
plants, and then the carnivores that relied on the herbivores. Around 75% of species became extinct,
including dinosaurs, mammals, giant marine lizards, fish, birds, and insects. Meanwhile, seawater
flooded around 40% of the world's continents ("Mass Extinctions").
However, such mass extinction opens up speciation – when new species are developed. After the K–
Pg extinction, new groups of organisms were on the rise. Giant boid snakes (12 – 15 meters) began
appearing on land and the teleost fish (diverse class of ray–finned fish) filled marine niches left
vacant. Most significantly, "Paleocene mammals would spread and evolve into the many ecological
niches left open by the extinction of the dinosaurs," ("Cretaceous: Extinction of the Dinosaurs").
The entirety of Earth's ecosystem was affected by the K–Pg extinction, caused by volcanoes,
oceanic shifts, and ultimately, an asteroid. Lucky for humans, mammals capitalized on the
opportunity

The Dinosaur Extinction Mystery By Michael Bento Essay

Recommended

Recommended

More Related Content

Similar to The Dinosaur Extinction Mystery By Michael Bento Essay

Similar to The Dinosaur Extinction Mystery By Michael Bento Essay (9)

More from Jennifer Wright

More from Jennifer Wright (20)

Recently uploaded

Recently uploaded (20)

The Dinosaur Extinction Mystery By Michael Bento Essay