Dinos in the Dark

When you think of dinosaurs and where they lived, what do you picture? Do you see hot, steamy swamps, thick jungles, or sunny plains? Dinosaurs lived in those places, yes. But did you know that some dinosaurs lived in the cold and the darkness near the North and South Poles?

If you're surprised, you're not alone. For many years, paleontologists believed that dinosaurs lived only in the warmest parts of the world, the places where turtles, crocodiles, and snakes live today. Later, these dinosaur scientists began finding bones in unexpected places.

One of those unexpected fossil beds is a place called Dinosaur Cove, in southeastern Australia. One hundred million years ago, in the time of the dinosaurs, Australia was connected to Antarctica, and both were located near the Earth’s South Pole. Today, paleontologists dig dinosaur fossils out of the ground, and think about what those ancient bones must mean.

What was the climate like at Dinosaur Cove 100 million years ago? It was cold! The average temperature was probably around minus 1 degree Celsius (around 30 degrees Fahrenheit), the sort of yearly weather you'd find today in southern Alaska. Not just the cold, but also Dinosaur Cove's location near the South Pole would make a huge difference for the dinosaurs living there.

Near the South Pole, for several months each year, the Sun never rose. Instead, Dinosaur Cove was plunged into a dark, cold winter night that didn't end until the spring or summer.

Go or Stay?

In some other parts of the world, dinosaurs probably migrated away from the darkness of the polar winter. But the animals at Dinosaur Cove couldn’t travel each year when the long night came. They lived on a peninsula of land, blocked to the north by a huge lake and to the south and east by ocean water. The only way out was to the west, and this way was too far for most of the animals at Dinosaur Cove to migrate.

To survive, these dinosaurs had to adapt. How did they change over time? Imagine you are a dinosaur at Dinosaur Cove. If you happen to have larger eyes, you will have a better chance of surviving than will a dinosaur with small eyes. Just as you probably got your big eyes from your parents, your children are likely to have big eyes, too. Over many generations at Dinosaur Cove, dinosaurs with bigger eyes became more common.

With their larger eyes, plant-eating dinosaurs could have seen the trees in the darkness - mostly evergreen trees that never lost their needles in the winter. At the same time, these big-eyed dinosaurs could have kept their eyes wide open for predators - the sharp-toothed and big-eyed meat eaters that would have hunted them.

Dino Blood?

Even with big eyes, though, the dinosaurs at Dinosaur Cove faced another problem - the cold. Turtles, snakes, and crocodiles are all reptiles. Almost all of them live in the warmer parts of the world, and for good reason. Their bodies don't produce their own heat, so they stay the same temperature as their surroundings. We say these animals are "cold-blooded," but their blood doesn't have to be cold. It's just as warm as the air or water around them.

If reptiles' bodies get too cold, they grow sluggish and slow. Some paleontologists wonder if maybe dinosaurs were more like birds than they were like reptiles. If dinosaurs were "warm-blooded" like birds, then they could have made their own heat. That would explain how dinosaurs might have survived through the cold, dark winters at Dinosaur Cove.

The Last Dinosaurs?

But that brings up another mystery. Most paleontologists today think the dinosaurs died out because the world got very cold very quickly. Perhaps a giant rock from space (an asteroid) slammed into Earth and threw up a cloud of dust, or perhaps ash from volcanoes blocked out the Sun. Either way, these scientists think, the world grew too cold for the dinosaurs to survive.

If some dinosaurs could survive cold polar winters, however, maybe they could also survive a colder planet. Could it be that the descendents, maybe the great-great-great grandchildren of the creatures at Dinosaur Cove, survived the extinction? Could they have been the last dinosaurs on Earth?

The marvelous thing about science is that each new answer creates more questions. Perhaps one day you will become a paleontologist and travel to the coldest parts of the world to search for the bones of Earth’s last dinosaurs. Be sure to pack a sweater!

Printable Files

Notes for assembling the book:
You can put this book together a couple of different ways. You can print out the pages, cut them in half and then order the pages back to front. Fold the stack in half and then staple the spine of the book. Pairs of pages can then be stapled or glued along the right edge.

You can also assemble the book as a foldable book.

To assemble the K-1 or 2-3 books this way, print the two pages and align the document pages so that the following book page numbers are in the lower right hand corner: front page and page 4. (The cover page should be on top and page 4 on the bottom). Set your copier to copy single pages into double pages and run the two pages in the order specified. Cut along the dotted line in the center of the double-sided page, place the book pages in order, fold, and staple along the spine.

To assemble the grades 4-5 book this way, print the four pages and align the document pages so that the following book page numbers are in the lower right hand corner: front page, page 6, page 2, and page 4. (The cover page should be on top and page 4 on the bottom). Set your coper to copy single pages into double pages and run the four document pages in the order specified. Cut along the dotted line in the center of the double-sided page, place the book pages in order, fold, and staple along the spine.

Electronic Books

A partnership with Content Clips has allowed us to provide electronic versions of our expository articles. Students can listen to the article as they read along on the screen.

These versions require Adobe Flash to view. If you don't have Flash, you can download it for free from the Adobe web site. You will also need to turn off your pop-up blocker to use Content Clips.

In each book, the play button (in the top right hand corner) will play an audio file of the text on that page, while the pawprint (bottom right hand corner) will turn to the next page.

Please note that the audio files take a moment to load on each page. Once the file has been loaded, a play button will appear in the top right hand corner of the page. To minimize the delay on each page, you can open the file and read through the article first. Once each page's audio has loaded, it remains loaded until you close the browser window. By preparing the article ahead of time, you can have students start at the beginning of the book and read without delays.

Grades K-1 electronic book

Grades 2-3 electronic book

Grades 4-5 electronic book

Content Clips is an interactive web environment designed to help K-12 teachers supplement their curriculum with compelling online resources and activities. By creating a free account, you can save resources and activities (such as the electronic books) to your own collection. You can also create your own interactive activities to use in your classroom. If you follow the links to the electronic books listed above, you will enter the site as a guest and will not be able to save them to your own collection. If you wish to save these stories in your own collection, create an account, login, and then search for "dinosaurs."

Related Activities

These lessons and activities can help you integrate this article into your science and literacy instruction. For additional ideas, please see Learning About Fossils Through Hands-On Science and Literacy in the Science and Literacy department of this issue.

Dinosaurs

Dinosaur Unit

http://www.sedl.org/scimath/pasopartners/dinosaurs/welcome.html This unit includes seven lessons about dinosaurs, including extinction, fossils, types of dinosaurs, meat and plant eaters, life cycle, and change. The lessons integrate science, language, math, and art through literature, activities, and centers. Spanish translations are also provided. This unit is designed for students in grades K-2.

Discovering Dinosaurs

http://school.discoveryeducation.com/lessonplans/programs/tlc-dinosaurs/index.html In this lesson, students examine images of dinosaur remains and tracks and make inferences about the dinosaurs represented. This lesson helps students understand the nature of scientific theory and how scientists can interpret fossil evidence in different ways. This lesson is designed for students in grades 3-5.

Context Clues

Text Talk: Julius, the Baby of the World

http://www.readwritethink.org/lessons/lesson_view.asp?id=25The importance of reading aloud to children is a long established tenet of reading instruction. This lesson supports the language development and reading comprehension of kindergarten through second graders. Through the use of the text talk strategy, students explain, develop, and expand upon story ideas. This lesson is designed to help students learn how to gain meaning from decontextualized language.

Five Types of Context Clues

http://www.schools.manatee.k12.fl.us/webdisk/Tyler/WebPages/5contextclues.pdf This handout, written for students, explains five types of context clues and provides an example of each.

Acquiring New Vocabulary Through Book Discussion Groups

http://www.readwritethink.org/lessons/lesson_view.asp?id=170This lesson explores various ways in which you can foster students' vocabulary skills through direct instruction and small-group discussions. While reading the text Pink and Say by Patricia Polacco, students identify words that are unfamiliar to them. Working collaboratively in small groups, they discuss the meaning of these new words using context clues from the text, prior knowledge, and print and online resources. They then apply their knowledge of the new vocabulary to further their understanding of the text. This particular lesson can be modified and reused for other areas of the curriculum, with moderate preparation and researching of topic-related resources. Extensions are included to further expand vocabulary acquisition and reading comprehension. This lesson is designed for students in grades 3-5.

Learn New Words Using Context

http://www.learnnc.org/lessons/BettyDeluca5232002364With guided practice students will use context clues to determine meaning of unfamiliar words in short passages. When students have completed the practice activities, they will read a newspaper or magazine article, picking out unfamiliar words and using context clues to decide what the word means. As a group activity they will share the article, the words, and their meanings with the class. This lesson is designed for students in grades 4 and up.

Context Clues (Learning Upgrade)

http://www.youtube.com/watch?v=qgaSmJKR9HMThis animated video teaches students how to use context clues to define new vocabulary.

Come talk about this article at the Beyond Penguins and Polar Bears blog!