Rock Cycle - Past Life (2A)

  • Exploring how dinosaur footprints are formed.
  • Learning about trace fossils.
  • trace fossil
  • imprint
  • Playdough or soft clay
  • Rock Cycle - Past Life (2A)
  • rulers

Students make and record prints from models.

A fossilized fish, preserved in shale


Some organisms leave information about their activities in rocks. Paleontologists use these clues to recreate how the organisms may have lived. These clues are called trace fossils. There are several main types of trace fossils. Tracks and trails are produced by an organism walking, crawling, foraging, or resting. Many dinosaur tracks tell us something about how large the dinosaur was, how fast it walked, and who walked with it.

Burrows and borings are the tiny tunnels worms and other creatures make as they move through the ground. Different types of burrows indicate feeding, dwelling, or foraging behaviors. 

Coprolites are fossilized animal excrements. They help in determining the approximate structure of the animals gut and may give some indication of the animals’ diet.

  1. This activity has the students create their own "trace fossil," by making a hand print. This hand print can provide information, just like a dinosaur footprint provides information about the lifestyle of dinosaurs. Tell the students that they are going to make an imprint much like the way dinosaurs made footprints.
  2. Students should roll the playdough or clay into balls and flatten it. Students should press their hands into the dough to make an imprint. Let them compare their hand prints with their neighbors. Have them look at the size, lines of the palm and other characteristics.
  3. Emphasize to students that they need to observe the differences very carefully. Measuring and recording these differences is very important. You may wish to ask them how their prints are similar to the dinosaur footprints and how they are different.
  4. Give students the dinosaur models and have them make imprints of the foot and skin of the dinosaurs. Make sure that footprints and skin prints of each model are created. Students should then compare the prints made by the different models. They should draw their findings on the lab sheet. Students may notice differences between the models and the animals in real life. Remind them that manufacturers of toys sometimes do not create realistic models. Explain that this is a way of getting information about a dinosaur without having a fossilized skeleton. Many times paleontologists rely on only "trace fossils."

    PLAYDOUGH RECIPE #1 (dough formed is not as durable as recipe #2)
         1 cup flour
         1\2 cup salt
         2 teaspoon cream of tartar
         1 cup water

    RECIPE #2. CLASSROOM QUANTITIES (alum helps preserve the playdough)
         5 cups of flour
         1 cup of salt
         2 tablespoons of alum
         2 tablespoons oil
         3 cups of very hot water

    Both recipes need to be cooked over medium heat and stirred for 3-4 minutes until the dough forms a ball and separates from the sides of the pan. You may add food coloring or glitter for special effects. For even distribution, add the food coloring at the same time as the water.

  5. In your kit you have a model of a Velociraptor, Stegosaurus, Triceratops, Apatosaurus, Pachycephalosaurus,  Ankylosaurus, Parasaurolophus, Styracosaurus, Tyrannosaurus, Brachiosaurus, and Edmontosaurus. Dimetrodon is in the collection but it is a mammal-like reptile and not considered a dinosaur.Below is some information of the dinosaurs.

Stegosaurus   Extremely small skull about 16 inches, but was 24 feet long, weighed about two tons, double row of large, bony plates with the largest about two feet wide and two feet tall;  end of tail were foot long spikes covered in tough horn;  back legs where twice as long as the front legs;  broad, three toed feet;  front feet had five strong clawed toes

Triceratops     long, sharp horns; bony frill around neck;  skull measured up to 7 feet, with two horns on the brow about 3 feet long; short horn on nose about 7 inches;  front of mouth was a sharp beak;  grinding teeth in back;  neck frill was solid sheet of bone;  was 30 feet long 10 feet tall, and 9 tons   Long hipbones were attached to a large number of vertebrate, making the body stronger;  walked on four legs, they were all thick;  on the feet there were short wide toes; five in front and 4 in back

Parasaurolophus   Hollow, 1 meter long crest acted as a resonator, producing a loud trumpeting noise. beak and toothed jaws

Brachiosaurus  52 teeth, large nasal opening at top of skull, 40-50 ft tall, 8.5 ft long; 50-80 tons;  4 strong legs, 14 neck vertebra with longest being 3 feet long;  neck also have complicated joint system to help strengthened;  front legs were longer to support neck;  had small feet for its size, with front foot and first 3 digits of hind foot with a claw;  neck up to 20 feet long

Tyrannosaurus   about 40 feet long and 12 feet tall, could rear up on its hind legs and reach 18 feet.  It weighed 6-7 tons, more than an elephant.  It walked on two legs and held its long tail straight out behind it  which helped to balance.  The back legs were strong enough to support the body, including massive angle bones.  Each foot had four toes, one small and three large ones.  The claws were large.    The arms and two clawed hands were small for its body and did not even reach its mouth.  It has special ribs that were opposite the vertebrate.  Massive skull was nearly four feet long.  60 sharp teeth embedded in 3 foot jaws


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