Jay Johnson - Dinosaurs

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Millions of

Years Ago

You see a lot of dinosaurs in movies and on TV shows. But do you think those are real dinosaurs?

First Dinosaurs Appear

Dino Timeline

MYA=Millon Years Ago

MYA

MYA

Triassic Period

Jurassic Period

Real dinosaurs are extinct that means they are dead and gone forever. Dinosaurs were animals, in the same big group as birds and crocodiles. They lived on earth a very long time ago way before people.

40,000 YEARS AGO

Dinosaurs Become Extinct

First People Appear

DINO Basics

Dinos lived million years ago

Dinosaur means terrible lizard

Today

MYA

Cretaceous Period

MYA

How do we know dinosaurs really lived on earth? Scientists called paleontologists study fossils. Fossils are the remains of things that lived millions of years ago. These remains have become part of rocks buried in the earth.

Rocky Records

There are many fossils of dinosaur tracks, bones, skin, and even eggs! In fact, scientists find a new dino fossil about every six weeks!

Over kinds of dinosaurs have been identified. Most of them have been found in the past years.

Dinosaur

Meals

Most kinds of dinosaurs ate only plants. Many of them had gigantic bodies with huge stomachs. And some had long necks to reach leafy treetops.

Other kinds of dinos ate only meat lizards, insects, and other dinosaurs. Most meat - eaters ran on two feet, rather than four.

They were fast runners, which helped them catch their dinner.

Some meat - eaters were big, but some were as small as chickens!

pOLACANTHUS (plant - eater)

A few kinds of dinosaurs ate both meat and plants. They liked variety!

baryonyx (meat - eater)

Allosaurus

(AL - o - SAW - rus)

This dinosaur weighed up to tons (1.8 metric tons). It was about feet (11 m) long and feet (3 m) tall at the hips.

Allosaurus was fierce. It was one of the biggest, strongest meat - eaters of its time. It had large teeth with

edges like saw blades. Its head

was as big as a first - grader!

Some people believe that Allosaurus looked for food usually other dinosaurs in a group of hunters called a pack.

When it lived:

About million years ago, Jurassic Period

fOssils found in:

Colorado, Wyoming, Utah, Oklahoma, New Mexico

diet: Meat

This four - legged dinosaur was a giant, weighing up to tons (72.5 metric tons). Brachiosaurus grew an amazing feet (30.5 m) long. The length of three of these dinosaurs would equal one football field!

Brachiosaurus

(BRACK - ee - o - SAW - rus)

Like the giraffe, this dinosaur had long front legs and a superlong neck so it could nibble leaves from the highest tree branches. Its head rose up to feet (18 m) off the ground thats as high as a four - story building!

When it lived:

About

million years

ago, Jurassic

Period

fOssils found in:

Colorado, Wyoming, Europe, Tanzania

diet: Plants

Brachiosaurus may have had a good sense of smell because it had huge nostrils on top of its head!

Stegosaurus

(STEG - o - SAW - rus)

Stegosaurus had a tail as long as its elephant - sized body (about feet or meters). With four sharp spines, the tail could be used as a great club to fight off meat - eaters!

Stegosaurus also had a double row of triangular plates from its neck to its tail. The plates probably helped protect the dinosaur from being eaten! Some of the plates were as small as saucers. Others were as big as truck wheels!

When it lived:

About million years ago, Jurassic Period

fOssils found in:

Western North America

diet: Plants

allosauruS

Iguanodon

(ig - WAN - o - don)

Chomp, chomp, chomp! Iguanodon was the first plant - eating dino whose fossils were discovered in modern times. They were found in England in 1825.

Iguanodons traveled together in herds that grazed along the edges of swamps and lakes. Their strong grinding teeth chewed up juicy ferns and reeds.

This dinosaur was heavy. It weighed up to tons (5.5 metric tons). It was feet (10 m) long and taller than two grownups balancing on each others shoulders!

When it lived:

About million years ago, Cretaceous Period

fOssils found in:

Belgium, England, Germany, Tunisia, Mongolia, China, South Dakota, Utah

diet: Plants

Velociraptor

(ve - LOSS - uh - RAP - ter)

Velociraptor lived in deserts. It had large eyes. It may have needed big eyes to hunt at night. It probably ate lizards and other small animals, tiny baby dinosaurs (called hatchlings ), and eggs.

PROTOCERATOPS