Dinosaurs
This presentation is the property of its rightful owner.
Sponsored Links
1 / 30

Dinosaurs PowerPoint PPT Presentation


  • 87 Views
  • Uploaded on
  • Presentation posted in: General

Dinosaurs. An era- extinct. Closer View. What are dinosaurs?.

Download Presentation

Dinosaurs

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Dinosaurs

Dinosaurs

An era- extinct


Dinosaurs

Closer View


Dinosaurs

  • What are dinosaurs?

  • Dinosaurs were the dominant vertebrateanimals of terrestrial ecosystem for over 160million years. The dinosaurs evolved from a group of early reptiles known as thecodonts, which arose during the Permian period (290-250 million years ago) and were dominant throughout the Triassic (250-208 million years ago.


Two major groups of dinosaurs evolved from the thecodonts

Two major groups of dinosaurs evolved from the thecodonts

The ornithischian (bird hips) dinosaurs

The saurischian (lizard hips) dinosaurs


C ommonalities of 2 groups

Commonalities of 2 groups

Both of these dinosaur lineages originated at about the same time.

Both evolved into many species that were ecologically important and persisted until about 66 million years ago.


Difference between the two dinosaur groups

Difference between the two dinosaur groups.

"Bird-Hipped" dinosaurs"

Lizard-Hipped" dinosaurs

  • They had beak-like bone in the lower jaw in front of the teeth, called a predentary.

  • Narrow palebral (the bone that crosses the outside of the eye socket)

  • Bony (ossified) tendons above the sacral area of the vertebrae

  • Opening below the nostrils (called the subnarial foramen)

  • An elongation some neck vertebrae (resulting in long necks)

  • A big thumb,

  • An extra, wedge-shaped ankle bone (the astragalus)


H ow did the dinosaurs die

How did the dinosaurs die?

This is one of the greatest mysteries of all times, and still waiting to be solved. All scientists agree that the last dinosaur died out for some reason about 65 million years ago


D ifferent theories of dinosaur extinction

Different theories of dinosaur extinction:

Greenhouse effect

Asteroid

ozone

Giant meteor


Greenhouse effect

Greenhouse effect:

The phenomenon where the earth's atmosphere traps solar radiation, caused by the presence in the atmosphere of gases such as carbon dioxide, water vapour, and methane that allow incoming sunlight to pass through but absorb heat radiated back from the earth's surface.


Asteroid

Asteroid

There is proof that an asteroid Over 9 miles wide stuck the earth on the tip of the Yucatan peninsula, in the Gulf of Mexico. Asteroids happen every now and then today, but a big one would be the size of a basket ball nowadays. A 9 mile long asteroid would change atmosphere all over the world. Massive forest fires would spread through countries, severe storms all over the world, poor air quality, ocean to ocean tidal waves, and probably the worst thing ever: It would eliminate ALL sunlight for longer than 6 months. This would surely kill 70% of all life forms. The only that would survive would be smaller animals hiding out through this destruction.

:


Ozone layer

Ozone layer

The ozone layer is like a protective shield against these rays. It blocks most of the harmful energy that the sun sends to the surface of the earth.


G iant meteor

Giant meteor

If a huge meteor hit the earth

The force of the impact would probably rise millions of tons of dust into the air. It might also shake the earth enough to start eruptions from many volcanoes.

The dense clouds of smoke and dust in the air would keep sunlight from reaching the surface of the earth. And for this reason most of the planets would die.


M y discussion ozone theory

My discussion: Ozone theory


To understand the ozone theory lets discuss

To understand the ozone theory,lets discuss ………

Ultraviolet rays

Volcanic eruptions

Ozone layer- definition and dynamics

Effect on living organisms (especially dinosaurs)


Ultraviolet rays

Ultraviolet rays

The sun is the natural source to all life. Without it there cannot be life. But the sun is so powerful that it does create dangerous substances such as the most common ultraviolet rays. Ultraviolet rays create a small amount of radiation which is harmful to all living organisms. It also is known to cause cancer as well, which is fatal.

This is where the ozone layer comes into effect to fend off these hazardous and dangerous rays. The ozone layer is like a protective shield against these rays. It blocks most of the harmful energy that the sun sends to the surface of the earth.


V olcanic eruptions

Volcanic eruptions

It is assumed that during the Cretaceous period there were many outbreaks of volcano's. When a volcano erupted it not only sprays millions of gallons of hot lava, but also a mass of a certain chemical called Hydrochloric acid. This poisonous gas

can deface the ozone layer. One volcano

would do much harm but scientists know

that during the Cretaceous period there

was not only one, but mass amounts of

aggressive behaviour by volcanoes around

the world.


Ozone layer definition and dynamics

Ozone layer- definition and dynamics

Definition

Ozone : The ozone layer is like a protective shield against these rays. It blocks most of the harmful energy that the sun sends to the surface of the earth.


O zone layer dynamics

Ozone layer dynamics

The ozone layer is roughly 1 ½ miles high in the atmosphere and is transparent to the naked eye.

This ozone layer can be damaged by pollution and it's common to hear from scientists that automobiles and big industries are causing damage to the ozone layer.

Of course there weren’t cars in the Triassic, Jurassic, and Cretaceous period so ozone should've been in perfect condition during these huge reptiles roamed the earth.

Actually there is one natural disaster that can damage the ozone layer really bad. Volcanos.


Effect on living organisms especially dinosaurs

Effect on living organisms (especially dinosaurs)

Most Dinosaurs did not have fur, and many were known not to be like crocodiles laying in water all of the time. This is proven by the way that their bodies are shaped. So we know that they ran around land and if the ozone layer broke apart then cancer is free to spread throughout the world

  • This would be the beginning of dinosaurs dying off.


Scientific evidence

Scientific Evidence

Dinosaur extinction theories you'd realize that many are linked to volcano's because of the proof of that timeline and the loads of volcano rock material found at the same ground level as the latest found dinosaur fossils

Dinosaur diggers have found that when they dig up dinosaur fossils that are dated from the Cretaceous period they also find a lot of volcano rock in the same area.


North american fossils

North American fossils:

At present the most informative sequence of dinosaur-bearing rocks in the world from the K–T boundary is found in western North America, particularly the late maastrichtian-age hell creek formation of Montana, USA.

In addition to rich dinosaur fossils, there are also plant fossils that illustrate the reduction in plant species across the K-T boundary


Marine fossils

Marine fossils

The mass extinction of marine plankton appears to have been abrupt and right a Further analysis shows that several processes were in progress in the late Cretaceous seas and partially overlapped in time, then ended with the abrupt mass extinction. 


The k t boundary and iridium

The K-T Boundary and Iridium

The Cretaceous–Tertiary extinction event, which occurred approximately 65.6 million years ago (ma), was a large-scale mass extinction of animal and plant species in a geologically short period of time.

Widely known as the K–T extinction event, it is associated with a geological signature known as the K-T boundary, usually a thin band of sedimentation found in various parts of the world.

Non-avian dinosaur fossils are only found below the K–T boundary, indicating that dinosaurs became extinct immediately before or during the event.


K t boundery continued

K-T Boundery continued…

Scientists theories that the K–T extinctions were caused by one or more catastrophic events such as massive asteroid impacts the cxichulub impact or increased volcanic activities.

Several impact crater and massive volcanic activity in the Deccan traps have been dated to the approximate time of the extinction event.

These geological events may have reduced sunlight and hindered photosynthesis, leading to a massive disruption in Earth's ecology.


Multiple effect

Multiple Effect

In a review article, J. David Archibald and David E. Fastovsky discussed a scenario combining three major postulated causes: volcanism, marine regression, and extraterrestrial impact. In this scenario, terrestrial and marine communities were stressed by the changes in and loss of habitats.

Dinosaurs, as the largest vertebrates, were the first to be affected by environmental changes, and their diversity declined.

At the same time, particular materials from volcanism cooled and dried areas of the globe.

Then, an impact event occurred, causing collapses in photosynthesis-based food chains, both in the already-stressed terrestrial food chains and in the marine food chains.


Evidence that discredits ozone theory

Evidence that discredits Ozone Theory

Multiple v/s Single cause effect

The major difference between this hypothesis and the single-cause hypotheses is that its proponents view the suggested single causes as either not sufficient in strength to cause the extinctions or not likely to produce the taxonomic pattern of the extinction.


Bibliography

Bibliography

http://pubs.usgs.gov/gip/dinosaurs/

http://www.waoy.org/26.html

http://en.wikipedia.org/wiki/Dinosaur

http://www.pbs.org/wgbh/evolution/extinction/dinosaurs/asteroid.html

Thunder Through the Prehistoric land of Dinosaurs’, 2004, John BonnettWexo (Wexo.J), Wildlife education.

Abc: web references

Abc: book references


Dinosaurs

Tyrannosaurus rex, Brontosaurus, triceratops…

… But how did they get their names?

Why are they so hard to say?

In 1842 more than 150 years ago, a scientist named Sir Richard Owen made up the name “dinosaur”. Well actual he called them deinos sauros. Those two words are Greek words. Deinos means terrible, sauros means lizard. So the word dinosaur really means terrible lizard. Dinosaur names all come from either Greek or Latin words. So part of each dinosaur name has either a Latin or Greek word in it some where .Perhaps that’s why they are so hard to say!!!!


Dinosaurs

Here is how it works.

  • Triceratops is the three horned dinosaur. In Greek the word tri means three, cerat means horn and ops means face- three horned face.

Do you see how it works? Tyrannosaurus rex is the fierce meat eater. Tyranno means tyrant, sauros means lizard, rex means king. So what do you think that means???????

Tyrant lizard king


T hank you

Thank you

……… Shreyas Gangwani 9HUU


  • Login