Gather all the materials before beginning the project. To make an apatosaurus footprint, simply hand draw a footprint on a piece of white paper. The heel is round and there are three pointy toes. Take this picture to an office supply store and have it enlarged and printed. The final measurement should be about 3 feet long and slightly over 2 feet wide. Cut out the footprint. Lay it on top of a piece of cardboard and trace around the footprint. This will transfer the image to the cardboard. Cut out the footprint from the cardboard to make the stamp.
Kindergarten students will use dough when stamping their apatosaurus footprint. How much dough you make depends on whether you are doing a class craft or individual crafts. If you want every child to make her own footprint, you will need a considerable amount more dough. For one footprint, combine 1 cup all-purpose flour, 3/4 cup salt, and 3/4 cup hot tap water. Combine the ingredients and knead to get a pliable dough. Keep the dough in an airtight container until you are ready to use it. However, you will have to knead the dough to soften it again.
Roll out the dough on a piece of wax paper for the kindergarten student. Use pieces of tape at the corners of the wax paper to help hold the wax paper in place while you are rolling out the dough. Apply a tiny pinch of oil or Crisco to one side of the apatosaurus footprint stamp. Let the student place the stamp, oily side down, onto his dough. Gently lift the stamp up to see the footprint. Write the student's initials on the dough using a black permanent marker.
Allow the footprints to air-dry for at least 24 hours, maybe longer depending on the thickness of the dough. You can place them in the sun to help quicken the drying process. Once it's dry, write "Apatosaurus Footprint" at the top. A black permanent ink marker works fine. Let your students place their bare foot into the footprint to see just how much bigger the apatosaurus foot is compared to their foot.