Science Skill Builder: Inference

Interpreting information obtained from fossils is like detective work. Many fossil bones have been found in limestone caves in Swartkrans in South Africa. Use clues from the fossil evidence presented below to determine how the fossils might have accumulated in the cave.

• The fossils are embedded in breccia, a sedimentary rock made of rock particles cemented together with limestone.
• The fossils include the skull of an early human child with two puncture wounds, a leopard jaw with a few teeth, and large bones from many types of mammals.
• Fossils from small bones such as ribs and vertebrae are not present.
• Trees grow near the opening of the cave. Trees protect the opening.
• The cave entrance is a hole in the ground that continues as a vertical shaft.
• Leopards are known to eat their prey in trees.

Using the information from the previous section, answer the following (Ansers may vary, possible answers are given):

1. Why might the location of trees near the cave entrance be important? (Since leopards eat their prey in trees, the remains of a leopard's meals are likely to be near trees.)
2. How might the early human child have received its wounds? (The human child could have been attacked by a leopard.)
3. What is the source of the bones from mammals? (The bones are left from the leopard's prey.)
4. Why does the leopard jaw only include a few teeth? (The others may have broken off or eroded.)
5. Why might small bones like ribs and vertebrae be absent from the cave? (They may have been scattered elsewhere, dissolved, or eroded away. Or, leopards may have eaten the small bones, not discarding them like the larger ones.)
6. Is it possible to know for certain how the fossils accumulated in the cave? Why? (It is not possible to know for certain, because the fossils accumulated a long time ago. However, scientists may generate a hypothesis supported by the evidence. The hypothesis for this sit is that leopards dropped bones into the cave as they ate their prey in the trees.)

Write a story about how fossil bones got into the cave over a million years ago. Make sure your explanation fits all the pieces of evidence given above. You may want to include a drawing or diagram.