Dinosaur Footprints: Choosing the Voice

Tracks Beneath the Spotlight

1Welcome to the dinosaur track gallery. Before you look up at the skeleton cast, examine the shallow marks beside your feet. A dinosaur pressed these tracks into soft sediment long ago. Other layers later covered the impressions. Under suitable conditions, tracks can be preserved as the sediment becomes rock. Unlike a bone, a footprint records contact between an animal and the ground. It offers evidence of an action rather than a piece of the animal's body.

2The display includes a replica of a track surface. The original slab remains in protective storage. A low barrier surrounds the platform. This replica was made by the museum's exhibit team. A spotlight shines across the shallow impressions. Notice how that introduction puts the replica before its makers. For listeners standing beside the display, the object is the starting point; the people responsible for producing it come later in the sentence.

3Now follow the row of prints toward the wall. Researchers compare the length of each footprint with the distance between successive prints. These measurements can help them investigate how an animal moved. A trackway does not supply a complete account of a dinosaur's day, however. Different animals can leave similar tracks, and the condition of the ground can affect an impression. Scientists therefore examine several clues before proposing an explanation for the marks.

4Our exhibit team tested the narration before recording it. Student listeners requested a pause after the instruction to follow the prints. The team added the pause and shortened a description of the platform. During the next test, the listeners found the first print more quickly. Their comments also helped the team separate information about ancient tracks from information about the modern replica. Both subjects belong in the guide, but listeners need to know which one a sentence describes.

5At the final stop, compare the replica with the photograph above it. The photograph shows the original surface, while the replica allows a closer view of its shape. Neither object answers every question about the animal that passed by. Together, they invite careful observation. As you leave, choose one print and describe what you can actually see. Keep that observation separate from any explanation you propose.