Cross-Section Fossil Excavation Card

You will need

• Cardstock or cereal box cardboardOne piece folded in half for the card base; wipe clean first

  Use a box that held food, not household chemicals; cardboard is not for chewing; recycle when the project is done.

• Plain paper in 3–4 neutral colorsTan, gray, brown, off-white; standard letter sheets cut into strips
• ScissorsSharp enough for cardstock; adult assists with the base fold if needed
• RulerEssential for consistent layer widths
• PencilFor marking measurements and sketching the fossil
• White school glue or glue stickGlue stick for paper layers; school glue for the card base fold
• Washable markersFor coloring the strata strips and drawing the fossil skeleton
• Permanent markeroptionalOptional; adult only, for labeling strata names on the finished card

  If used, the adult handles this step only — permanent marker does not wash off skin or surfaces.

Steps

1. 1

   Plan the strata layers

   Before any cutting, sit with your child and talk through the concept: rock forms in horizontal layers over millions of years, and the oldest layers are deepest. Sketch four horizontal bands on a scrap of paper and label them Top Layer, Layer 2, Layer 3, and Fossil Layer. Explain that each paper strip represents millions of years of rock. Ask: 'Which layer would a paleontologist have to dig through first?'

   Tip: Naming the layers together increases investment in getting the depths to look right.

2. 2

   Draw the fossil on the bottom strip

   Cut the darkest paper into the widest strip — about four inches tall and the width of the card base. This is the fossil layer. Have your child draw a simplified dinosaur skeleton on it in pencil first, then trace with a washable marker. It does not need to be anatomically correct; a recognizable backbone, a skull, and some ribs are enough. Set it aside to dry completely before the next step.

   Tip: Drawing the skeleton with the strip lying flat is easier than drawing on an assembled card.

3. 3

   Cut and color the strata strips

   Cut three more paper strips in the remaining neutral colors, each one about half an inch narrower in height than the layer below it, so when stacked you see a stepped edge like a cliff cross-section. Have your child color each strip with a washable marker in a single color or a light texture — diagonal pencil lines suggest rock grain. Encourage them to make each layer look different from the others.

   Tip: Consistently shading in one direction gives the strips a geological, layered look.

4. 4

   Score and fold the card base

   Fold the cardstock in half to make the card base. If the cardstock is stiff, use a ruler edge and the back of a scissor blade to score the fold line lightly before folding — press along the scored line, then crease firmly. The card needs to open flat and close flat; a weak fold here causes problems when layers are glued in. Help with this step if the material is resisting.

   Tip: Running a fingernail firmly along the fold after scoring tightens the crease.

5. 5

   Layer and glue the strata

   Open the card flat. Working from the bottom up, glue the fossil strip first at the very bottom of the inside, then each successive strip above and slightly overlapping the top edge of the one below it. The top strip should sit nearest the card's center fold. Each strip should reveal the one below it at the bottom edge, like stepped rock strata. Press each strip flat for thirty seconds before adding the next.

   Tip: Check that the card still closes flat after adding each strip — correct any overlap before the glue sets.

6. 6

   Add geological labels

   Once all strips are dry, your child can write the names of geological time periods along the left edge of each strip in pencil — Cretaceous, Jurassic, Triassic are real examples that work well. Say: 'Paleontologists know which period a fossil is from by identifying which rock layer it was found in.' If they want more permanence, you can trace the pencil labels in washable marker.

   Tip: Looking up the actual colors associated with each period in a geology chart makes the strip colors more intentional.

7. 7

   Close and present the card

   Close the card and let your child write a title on the front — something like 'Fossil Record' or the name of the dinosaur skeleton inside. Encourage them to open it slowly for someone else, narrating which layer they're looking at as each strip comes into view. That presentation moment is the payoff the whole project has been building toward.

   Tip: Drawing a small shovel or a magnifying glass on the front cover signals that there is something to discover inside.

Take it to the table

Materials checklist, the steps and the variations on one Letter page.