Dinosaurs4th Grade Science

By Ashleigh Johnson

Standards Being Addressed Earth Science: Earth in Space and Time

The identification and comparison of common objects in the sky begins the study of Earth in space. Through long term observations of the sun and moon, students identify patterns in movement and collect data to summarize information regarding the orbit of the Earth around the sun, and the moon around the Earth. Models and activities provide the tools to demonstrate the orbits and explain the predictable cycle of one month in the phases of the moon, and day and night as the apparent movement of the sun and moon across the sky. Students explore the history of the Earth through evidence from fossils and compare fossils of life forms with organisms that exist today. The underlying theme within the physical, life, and Earth science is energy and specifically energy from the sun. Students can make connections between the heat and light energy from the sun and the dependency of all living things on the sun.  K-7 Standard L.EV: Develop an understanding that plants and animals have observable parts and characteristics that help them survive and flourish in their environments. Understand that fossils provide evidence that life forms have changed over time and were influenced by changes in environmental conditions. Understand that life forms either change (evolve) over time or risk extinction due to environamental changes and describe how scientists identify the relatedness of various organisms based on similarities in anatomical features.  K-7 Standard E.ST: Develop an understanding that the sun is the central and largest body in the solar system and that Earth and other objects in the sky move in a regular and predictable motion around the sun. Understand that those motions explain the day, year, moon phases, eclipses, and the appearance of motion of objects across the sky. Understand that gravity is the force that keeps the planets in orbit around the sun and governs motion in the solar system. Develop an understanding that fossils and layers of Earth provide evidence of the history of Earth’s life forms, changes over long periods

E.ST.E.3 Fossils- Fossils provide evidence about the plants and animals that lived long ago and the nature of the environment at that time. E.ST.04.31 Explain how fossils provide evidence of the history of the Earth. E.ST.04.32 Compare and contrast life forms found in fossils and organisms that exist today.

Today you will have your first taste of what life was like before you. It hasn’t always been a life of fast food, computers, and cars. Believe it or not there was a time when schools, stores, and sports didn’t even exist! Another species that is now extinct, roamed and ruled the earth. A species

called Dinosaurs. So become the best paleontologist you can be and come with an open, ready mind to learn about the time of the dinosaurs, the dinosaurs themselves, and how we even know they existed!

The name “dinosaur” means “terrible lizard” because of the close resemblance

they have to modern day lizards.

Modern

Lizard

Din

osa

ur

When Did the

Dinosaurs Exist?

The Dinosaurs began ruling the earth about 245 Million years ago during the Mesozoic Era. The dinosaurs ran the planet during the Triassic, Jurassic, and Cretaceous time periods.

When the dinosaurs roamed there were no houses, stores, cars, people, buildings, roads, phones or even mail! They lived in a world where it was full of nature and nothing but nature. There were many , many trees and ferns The climate was tropical and warm, different than what we know today. There has not been any concrete evidence found that suggest humans and dinosaurs existed together.

Dinosaurs fit into 1 of 3 different categories.

1. Herbivore- Only eats plants

2. Carnivore- Only eats meat3. Omnivore-

Eats both plants and meat.

Back to the Quiz!

Tyrannosaurus RexAlso know as the T-Rex or the

Tarbosaurus, the Tyrannosaurus Rex is one of the most notorious and feared carnivores but are classified by scientist as more of a scavenger. They are bi-pedal meaning they walk on two thick, muscular legs and feet. They have two other small short limbs on their upper body, you may recognize them as arms. Their running speed averaged between 25 -45 mph. Their average height was 23 feet with an average length of 42 feet and an average weight of 16,000 lbs! That’s comparable to an elephant of a semi-truck! Their skulls measure about 5 feet in length, that’s taller than you!

More about the T-Rex please! Pretty Please!!

AnkylosaurusThe ankylosaurus, a herbivore, is a

wide“tank-like” dinosaur that was completely protected from carnivores with thick, hard, plates covering its entire body. They were on average 20-30 feet in length, 6 feet wide, 4-5 feet tall. weighed as much as 5 or 6 tons, and sat low to the ground in comparison to other dinosaurs. The Ankylosaurus used their club tail as a defense mechanism. It was covered in plates made of bone, known as osteoderms. It was believed that its tail had enough strength to break the bones of its attacker with a single swing! These dinosaurs prefered a tropical climate.

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Tric

era

top

sThe Triceratops, also commonly known as the three-horn ( because of the three horns on its head) was the most well-known horned dinosaur. It can be compared to the modern day rhinoceros. It was an herbivore and used its beaked mouth to tear plant fibers. It was around 30 feet long, 7 feet tall at its hips, and weighed 6-12 tons! Its legs were short, thick and muscular and carried the heavy weight of its body evenly. The plated shield jetting off of the back of its head was used for protection. Triceratops also traveled in herds.

Not Enough Information?

Back to the Quiz!

VELOCIRAPTOR

The Velociraptor is a carnivore like the T-Rex although it is a hunter (Pack hunter) rather than a scavenger and it is much smaller in size. It can reach up to about 6 feet in length, 3-4 feet high, and around 30 lbs on average. They could reach speeds of 40 mph for short distances. As their defense and hunting weapon they used the deathly sharp, retractable claws that had on each of their feet. Their bodies were covered and feathers and its looks can be related to a big chicken! They were very fast and agile, bipedal, dinosaurs. The preferred a desert like environment with little water.

Check it out!

Stegosaurus

The Stegosaurus was about 14 feet tall, 28 feet long, and weighed around 6,800 pounds. Its size be can be compared to a school bus. Even with its large size, its brains were only the size of a walnut and weighed only 80 grams! Its back contained 17 boney plates that stuck out towards the sky as well as a four boney spikes on its tail. The purpose of these pates was believed to be regulation of temperature. The plates are suspected of having blood vessels in them that absorbed heat from the sun. The plates were also used as a defense. It was an herbivore and had a beak –like mouth with no teeth in the front. It did have teeth on the sides.

LetsFind

More!

Ap

ato

sauru

sThe Apatosaurus, also known as the brontosaurus and the

long neck, is a very gentle herbivore. It was one the

largest dinosaurs of all. It grew to 70-90 feet in length, weighed 33-38 tons and was

10-15 feet tall. It could stand on its hind legs to reach

leaves on tall branches, but it normally walks on all four

legs. It was a very long neck and tail. The tail was used to

swing at attackers. Its nostrils were located on the top of its

head so that it can spend great lengths of time

underwater. This I also believed to be the. They lived

along riverbanks and swallowed rocks to help

digest the tough plant fibers because its teeth were not

sufficient.

PterodactylThe Pterodactyl made its home in trees and caves, similar to our modern day bat. While not technically considered a dinosaur because it flew, it is a winged reptile that lived during the time of the dinosaurs. It had a wing-span of up to 40 feet wide. and were made of a leathery type skin. Three claws extended out of the wing at about the midpoint of the wing. Their bones were light and hollow, some were coated in fur. They ate insects and ocean creatures so they were considered carnivores. They had full mouths of around 90 bristle like teeth.

Where are the dinosaurs now?

The Dinosaur species is now extinct, meaning every dinosaur that ever existed is no longer living. The entire species died off and they no exist in modern times. There are several theories the answer the question of how this happened. The most promising theory is the meteorite theory which has the most concrete evidence. Back to the Quiz

!

The Asteroid Theory

It is believe that when the asteroid hit the earth, it caused a massive, drastic climate change that the dinosaur species could not live through. The dinosaurs that were not killed when the asteroid hit, dies of other cause such as starvation or freezing. The evidence of this asteroid is found in the layers of our Earth. As scientist have investigated, asteroids have been found to contain extremely high levels of iridium. Non-coincidentally, a very thing layer of iridium has been found in our Earths crust which is where a majority of the dinosaur remains have been located leading us to believe they were extinct when there were high levels of Iridium present. Leading many to believe only one thing, the asteroid theory. Keep in mind however, there are many other theories and much more evidence arguing for the asteroid theory.

If the Dinosaurs are extinct, how do we know about them?

When the Dinosaurs died, they left behind all kinds of evidence for us to find so we could learn about them and what life was like in the past. The most helpful evidence they left behind was something called a fossil.

Foss

ilsFossils are signs and

remains that have been preserved in the Earths crust for our finding. There are many different kinds of fossils. They can be the imprint left in a rock, a skeleton left behind, and even footprints or tracks. They can be dried, frozen or smothered and preserved in a bed of clay.

Now that you’ve read…• When the dinosaurs lived

•Where the name “dinosaur” comes from• What it was like when they lived

• What the dinosaurs ate•A few specific dinosaurs and what they were

like•Theories of how the dinosaurs became extinct

• How we know about dinosaurs• What a fossil is

Now, let’s see what you’ve learned with a mini quiz!

Question 1

Which dinosaur that you read about can be compared to the

modern day rhinoceros?

A. Tyrannosaurus RexB. AnkylosaurusC. Triceratops

D. Stegosaurus

Thank you for joining me on this fantastic journey through time! I hope you were able to

learn how different the Earth was billions of years ago and even though the creatures

were so different, they are still comparable to many animals we know today! I hope you

were able to what happened to end the dinosaur species, how they left evidence

behind and how we find clues and use them to learn about the past.

These small, fun lessons will give you the foundation you need to learn even more

about the history of our Earth and how fossils are a gift that lead us to the past! Enjoy!