Tortoises--Bones on their Backs

Turtles are found in almost every part of the world. Find out what we can learn from these fascinating creatures and create a science project that will WOW everyone!

• 1.

  A tortoise’s shell is a living, integrated part of the animal similar in nature to human hair or nail. A tortoise’s shell, its skeleton, is made of 50 bones, a modified vertebrae, and bony skin plate. When the shell is damaged, it bleeds. Amazingly, tortoise shells sometimes regenerate to repair the damage.

• 2.

  Look at photographs of tortoises, especially ones such as the Indian Star and the Asian Flower Back. Notice the patterns and colors found on these ancient species. Find out about how turtles are being affected by changes in the Earth’s climate, such as rises in sea temperatures.

• 3.

  Here are some tips for completing your sculpture. Create an armature from crumpled aluminum foil. Build up the vault of the shell. Shape the neck, tail, and four legs.

• 4.

  Choose several Crayola Model Magic® colors to make a realistic replica of one species of tortoise—background, highlights, and marbleized colors. Mix original hues by blending two or more colors, or adding washable marker color to Model Magic and kneading to blend. Plan for a textured, realistic look for your magnificent creature.

• 5.

  Build extremities. Cover all the foil extremities with a Model Magic background color such as black. Form small cones for toes (turtles walk on their toes). Attach toes to legs. If Model Magic pieces dry while you work, use Crayola School Glue to attach t

• 6.

  The legs and tail of a tortoise may have two differently textured surfaces. To cover the underneath side, form small balls of Model Magic in a color different from the background. Flatten these balls on the background. For the top side of the legs and tai

• 7.

  Shape the neck and head with a beaked nose, open mouth (but don’t extend the tongue because turtle tongues can’t protrude out of the mouth), and hooded eyes on either side of head. Apply similar colors and modeling techniques used for the legs and tail to

• 8.

  Assemble lower shell (plastron). Run a flat ridge of background color down the underside of foil from the neck to the tail (these are the cartilaginous bones that evolved from collarbone and ribs). Next, shape flat wedges (osterderms or fused plates)

• 9.

  Construct upper shell (carapace). Build wedges similar to those made for the plastron only with more dimension and shades of colors. To form the vault of the top shell, radiate wedges out from a center circular plate. Again layer marbleized shapes to enha

• 10.

  Connect parts. A bony structure called the bridge joins the upper and lower shells. Mold the underneath part of the bridge. Design the top side part of the bridge similarly to main shell. Attach shells to these. Use more modeling material to reinforce

• 11.

  Glaze the tortoise. Mix equal amounts of glue and water to make a glaze to strengthen the figure and give it that shiny tortoise look. Cover your craft area with newspaper. Brush on the glaze. Air-dry.

• 12.

  Label and exhibit your magnificent creation in a science fair, art show, or other major event. Offer details about the turtle’s habits, habitat, and prognosis for future survival.

Benefits

• Students gather information about tortoises including details about body parts.
• Students research the effects of climate change on turtles’ lives.
• Students realistically reproduce textures and colors of turtles using modeling techniques to create 3-D sculptures that illustrate their findings.

Adaptations

• Explore how a turtle’s shell affects its life, dictating the way that it breathes and moves. Find out why some turtles have a flatter shell. Study the "shell" of a leatherback turtle. How have turtle shells changed during 200 million years? Prehistoric tu
• Look at the three types of turtles: tortoises (who are land animals that sometimes go in water), terrapins, and sea turtles (both live in the sea and lay eggs on land). There are eight species of sea turtle, more than 100 types of tortoises, and 180 terra
• Find out why balloon releases, including strings, are a danger to turtles and other marine animals.
• Delve into the role that turtles play in the various creation myths of Native American tribes such as the Iroquois, Huron, and Hopi. Find out about the Hindu belief that the universe is balanced on a turtle shell.
• Thirty-six species of turtle are endangered. Investigate the reasons for this including egg harvesting, adult capture, and habitat destruction. Learn why repopulation is not a quick and easy solution. Find out what changes are being made to help resolve t
• Assessment: Does the sculpture accurately exemplify the three parts of the shell and the turtle’s body parts? Is the coloration accurate? Are colors and various forms of modeling techniques used to create realistic texture and dimension?