Title: Footprint Detectives: Making Inferences Using Dinosaur Trackways

Author: Carol Moertl, Shady Lane Elementary School, Menomonee Falls, WI 53051 Email address:pmoertl1@execpc.com

Grades: 1-2

Overview of Lesson:

Using their own feet and scale dinosaur models, students will make observations, examine data, and form hypotheses about footprints and dinosaur trackways.

Suggested Time: one 30 minute session and three 40 minute sessions

Students' Prior Knowledge:

Students need to know that dinosaurs are a group of animals that lived long ago. Paleontologists learn about them through examining fossils, the ancient remains or impressions of plants and animals. Students should have had experience examining different fossil remains or casts of fossils. Students should know how to measure using a centimeter ruler.

Background Information:

Dinosaur footprints or trackways are what paleontologists call trace fossils. Trace fossils are not actual remains but the tracks, skin impressions, or the coprolites (fossilized waste) that dinosaurs left behind. Paleontologists can learn a lot about dinosaurs by looking at their tracks. They make inferences about:

• the size and shape of a dinosaur’s foot
• whether a dinosaur walked on two or four legs
• whether a dinosaur was a carnivore or herbivore
• how big it was (hip height was about four to five times the foot length)
• how fast it moved
• if dinosaurs travelled in herds (lots of overlapping and parallel trackways) and the direction they were travelling
• dinosaur behavior, including fighting (two sets of prints in a chaotic pattern)which dinosaurs were common in an area
• when certain dinosaurs appeared and disappeared in an area (Tracks are found in several successive layers of rock.)
• what the environment was like when the dinosaurs lived (Tracks are most commonly found along shorelines, and certain kinds of tracks are more likely to be found in different kinds of rock. Shallow tracks might indicate that the footprints were made at a dry time when lake levels were low. Deeper tracks might indicate that they were made under wetter conditions when lake levels were high.

Two excellent reference books are 

Tracking Dinosaurs: A New Look at an Ancient World by Martin Lockley, Cambridge University Press, ISBN: 0-521394-63-5 and 

Dinosaur Lake: The Story of the Purgatoire Valley Dinosaur Tracksite Area by Martin G. Lockley, Barbara J. Fillmore, and Lori Marquardt, published by the Colorado Geological Survey, ISBN 1-884216-53-6.

Materials:

Session 1:

• books about animal tracks
• Venn diagram

Session 2:

• two dish tubs (one for flour/chalk; the other for cleanup water)
• flour or ground up chalk, enough to cover bottom of tub up to one inch
• black paper from a roll cut into 12-foot lengths, enough for all the students to have a chance to make tracks
masking tape
• paper towels for cleanup

Session 3: 

• slide projector
• slides of dinosaur trackways
• plastic tracings of dinosaur trackways from Colorado

Session 4: 

• stick of clay for each student
• dinosaur models
• tissues to clean off models’ feet

Student Activities:

Session 1: The teacher reads aloud and discusses a book with students about animal tracks. Suggested title: Whose Tracks Are These? A Clue Book of Familiar Forest Animals by Jim Nail, ISBN 1-57098-078-0. Have students make observations about the tracks, regarding size, shape, direction of travel, etc., and make inferences as to what animal they think made a particular trackway. Using a Venn diagram, compare and contrast several sets of animal tracks.

Session 2: Using black paper from a roll and flour or ground up chalk, have students make their own footprint trackways. Put a tub of flour or ground up chalk on the floor at one end of a 12-foot-long piece of black paper taped to the floor. With their shoes off, have one or several students at a time make trackways according to teacher directions. Have them clean off their feet with towels and the tub of water.

Some track suggestions:

• Have one student walk slowly across the paper.
• Others can run, skip, hop, or jump.
• Have two or three students walk across side by side.
• One can follow another.
• Students can walk across the paper at different angles.
• Have two students mill about in the middle of the paper.

After each trackway is made, have children examine it closely, noting the clues that tell how it was formed. After several trackways have been made and discussed, have most of the class cover their eyes while one or more students make trackways according to teacher directions. With eyes uncovered, the rest of the class become footprint detectives to uncover clues and make inferences about how each new trackway was formed.

Session 3: The teacher shows slides of dinosaur trackways taken in Colorado to the class and compares them with animal tracks and student footprints. Use the terms trace fossils, sauropods (the big, long-necked herbivores) and theropods (carnivores) when comparing and contrasting the trackways. Tape the plastic tracings of the various trackways on the floor and have the students make inferences about them. Questions to answer: What kind of dinosaur(s) made these tracks? How did the dinosaur(s) move?,etc.

Students will notice that most of the footprints look rather “blobby” or indistinct. The teacher at this point can discuss erosion and wetness conditions. (See background information.) The teacher can also point out that sauropods usually put more pressure on their toes. Explain the arrows on the plastic that show the direction of the mud ridges that built up as the dinosaur stepped. Tell the students that all sauropod trackways found so far show that they were walking.  Compare the theropod trackways. Which one shows that the theropod was probably running? (The one with the bigger stride)

Give each student a chance to walk on a tracing in the way he/she feels the dinosaur(s) walked when making the original trackway. Using centimeter rulers, have the students measure the length and width of the footprints and the distance between prints. Discuss their findings.

Session 4: Culminating activity and assessment

Each student is given a piece of clay which he/she flattens into a rectangular shape suitable for a trackway. Then using dinosaur models, the student presses the model’s feet into the clay to make a trackway. The teacher will demonstrate use of the clay and the models before the students begin. Dinosaur feet must have all clay removed from them when trackways are finished. Have students remove clay with a tissue.

The students then share their trackways in small groups with group members making inferences about them. Each student should be able to explain what can be learned about dinosaurs from his/her particular trackway.

Teacher Notes:

A Venn diagram transparency on the overhead works well.

Every student must have a chance to help make a trackway and to walk on the plastic trackway copies. For pictures and directions for making plastic trackways, look under Classroom Resources on this website.

Limit each student to no more than two dinosaur models. Otherwise, their trackways will be a mess!

Vocabulary:

inference, tracks, trackway, compare, contrast, Colorado, trace fossils, sauropod, theropod, herbivore, carnivore, centimeters, erosion, models

Interdisciplinary Connections:

Language arts - listening and discussion skills

Math - measuring using a centimeter ruler

Science - making inferences from observations

Social studies - map work - Where is Colorado?

Technology - word processing stories about trackways (extension)

Art - illustrating stories (extension)

Extension activities:

1. Have students with a partner compare and contrast two different animal trackways.
2. Have students look for animal trackways in their neighborhoods.
3. Have students make plaster casts of an animal footprint that they have found.
4. Have students use their own ideas to make various footprint trackways.
5. Have students use rubber dinosaur footprint stamps and an inkpad to make trackways.
6. Have students write and word process a story about their clay trackways and make illustrations of the dinosaurs they used.

Wisconsin State Science Standards:

C4.2

http://www.dpi.state.wi.us/standards/scic4

Use the science content being learned to ask questions, plan investigations, make observations, make predictions, and offer explanations

C4.4

http://www.dpi.state.wi.us/standards/scic4

Use simple science equipment safely and effectively, including rulers, balances, graduated cylinders, hand lenses, thermometers, and computers, to collect data relevant to questions and investigations

C4.5

http://www.dpi.state.wi.us/standards/scic4

Use data they have collected to develop explanations and answer questions generated by investigations

C4.7

http://www.dpi.state.wi.us/standards/scic4

Support their conclusions with logical arguments

Wisconsin State Math Standards:

A4.3

http://www.dpi.state.wi.us/standards/matha4

Connect mathematical learning with other subjects, personal experiences, current events, and personal interests

• see relationships between various kinds of problems and actual events
• use mathematics as a way to understand other areas of the curriculum (e.g., measurement in science, map skills in social studies)