Power jaws

At-home activity: Crocodile jaw power

biology, earth scienceAndy Chambers, Summer Camps DirectorOct 23, 2020

Crocodiles have relatives going back more than 200 million years, and in fact, paleontologists can tell the crocodile’s evolution story with the help of studying extinct crocodyliforms to compare the anatomy with the anatomy of living crocodiles.

The crocodiles we see today are known for their powerful, V-shaped muzzles that have the most powerful bite in the world! Some crocodiles have long, narrow snouts while others have short, wide snouts; the length of their jaw determines what they can catch to eat. 

How strong are crocodiles’ jaws, and what part of the snout is the strongest? We can discover the answer by using an everyday pair of scissors.

Materials:

  • 2 sheets of copy paper

  • Scissors 

  1. Take a sheet of paper and your scissors. Open your scissors so that the blades are barely open.  Using the tips of your scissors, cut five snips along the edge of the paper. Rate your effort. Was it easy, difficult, or impossible to cut the paper? How were you able to make the cuts? Write down or type your response if you want to keep track of your data!

  2. Fold the paper in half so that you now have two layers of paper. Use the tip of your scissors and repeat the five-snip test. Rate your effort. Was it easy, difficult, or impossible to cut the paper?

  3. Fold the paper in half again and do the five-snip test, still keeping the scissor blades barely open. Repeat folding and doing the snip test until it becomes impossible to cut the folded paper. 

  4. Will opening the scissor blades wider make a difference in how they work to cut the folded paper? Try the five-snip test again keeping the scissor blades further apart. Rate your effort. Was it easy, difficult, or impossible to cut the paper?

  5. What if you try cutting with the middle or base of the  scissor blade? Take your second piece of paper and do the five-snip test with this new place on your scissor blade each time you cut. 

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  6. Try folding the paper in half as many more times as you can, repeating the five-snip test each time. How many more folds can you do before the snip test becomes impossible again? 

After you have completed the snip tests, think about or record your answers to these questions: 

  • Which place on the scissors blade cut through the most layers of paper? Were you cutting quickly or slowly?

  • Which place on the scissors blade could you cut the fastest? Were you cutting through a lot of layers of paper or just a few?

  • What place on the scissors blade gave you the most power for cutting?

  • What place on the scissors blade gave you the fastest speed cutting?

What is going on? 

When the scissors were barely open and you were cutting through a couple layers of paper, you were able to cut quickly and you weren't using a lot of power. Then when you folded the paper so you had many layers, you couldn't cut as quickly and had to use more power. 

What does this have to do with crocodiles?

Think of the paper as different animals that a crocodile could catch to eat, for example an insect, a fish, a turtle, and a zebra. 

  • What kind of animal could one layer of paper represent? 

  • What kind of animal could sixteen layers of paper represent? 

  • What prey animals could the other layers of paper represent in a crocodile’s diet?  

  • What animals would a crocodile have to be fast but not powerful to catch? 

  • What animals  would the crocodile have to be powerful but not fast to catch? 

  • If scissors represent a crocodile's jaw, what part of the jaw has the most power? How do you know this?

Are you feeling as strong as a crocodile? Use your new knowledge to cut out a Crocodile Snowflake or a Row of Crocodiles. 

Crocodile Snowflake

  1. Download the template below and fold the paper exactly along the dotted horizontal fold line.

    Download

  2. Lay the paper on a flat surface with the paper crocodile side down and the folded edge toward you.

  3. Put your right pointer fingernail on the dashed line where it meets the folded paper edge, then fold the bottom left corner up to align the folded edge UP TO the dashed line, but not over it. 

  4. Next, bring the bottom right corner up and align the length of the fold to the left edge. 

  5. Lastly, fold the paper in half again. Keep the points of the paper sharp and all layers aligned. Cut along the guide to create your crocodile snowflake!

Row of Crocodiles

  1. Download the template below and lay the paper print-side down on a flat surface with the instructions end closest to you. 

    Download

  2. Hold the left edge of the paper down and raise the bottom edge of the paper up to find the dotted fold line labeled (1). 

  3. At the left edge, crease a finger’s width of the fold on the dotted line and align the left edges of the paper. 

  4. Slide your fingers from left to right to crease the fold you just made. 

  5. Repeat steps 1-3 on the dotted fold line labeled (2). 

  6. Fold the top edge of the paper down and align the left edge, then crease from left to right. 

  7. Fold the paper in half the long way so that you can see half of the crocodile outline. 

  8. Cut the folded paper along the solid black lines. 

  9. Lastly, unfold the paper and flatten the creases to reveal your row of crocodiles! 


One final step: Show us your crocodilian creations on social media using the hashtag #ShareYourDiscovery!