Jun. 03, 2011

Fossil Detectives

by Science Friday Education

Click to enlarge images
Paleontology is the study of ancient life. Paleontologists examine plant and animal fossils for clues about the past, and try to reconstruct past environments and the interaction of prehistoric organisms within a particular environment. Paul Serreno, the paleontologist featured in this Science Friday video, specifically studies dinosaur evolution by finding, examining and comparing dinosaur fossils.
In this activity, students will learn about the two main types of fossils, body and trace fossils. Students will observe and examine a set of fossils to classify them as body fossils and trace fossils. Students also will act as paleontologists and try to identify each fossil.
Grade Level: 6th – 8th grade
Subject Matter: Paleontology (Life Science and Geology)
National Standards: NS.5-8.1, NS.5-8.3, NS.5-8.4
Reporting in the journal Science, Paul Sereno, Ricardo Martinez and colleagues describe Eodromaeus murphi. This dinosaur was four feet long, weighed fifteen pounds and lived 230 million years ago, just a few million years after dinosaurs first evolved. Eodromaeus murphi looks like its contemporary Eoraptor, except for its long canine teeth. Those suggest that the newly-discovered dinosaur is an ancestor of the predatory dinosaurs, including T. rex.
Activity Materials
Body and trace dinosaur fossils (Recommended: Dinosaur Museum In a Box kit available at
Magnifying lens, one for each pair or group of students
Note: This lesson plan can be modified to use any set of fossils as a substitute as long as the set includes body and trace fossils.
Paleontology: the study of ancient life.
Fossils: the preserved traces or remains of plants and animals.
Body fossil: fossilized remains of the actual body parts of an organism such as bones, teeth and claws.
Trace fossil: fossilized remains of an organism’s activity or behavior such as tracks, eggshells, nests, and coprolites.
Coprolite: fossilized feces.
What To Do

Prep: Label each fossil in the set by letter, and create an information sheet that identifies the fossil and whether it is a body or trace fossil. Students will use this sheet as a reference towards the end of the activity, during the review.

1. Begin the lesson by having students watch the Science Friday video, “Fossils from the Dawn of Dinos.” Discuss with students how fossils are formed. What are some different types of fossils a paleontologist might find at an archaeological site? What is the difference between body fossils and trace fossils?

2.  Inform students that they will act as paleontologists by examining several dinosaur fossils and determining whether they are either body or trace fossils. Help students create a four-column chart on a sheet of paper or in their notebooks. Label the columns from left to right "Fossil Letter", "Fossil Sketch", "Predictions", and "Fossil Type".

3. Hand out one fossil to each pair or group of students. Have students observe the fossil using a magnifying lens. Students should sketch a diagram of the fossil, with the letter on the label of their fossil, in the first column of their chart. Are there any patterns or distinguishing features on the fossil? What does it look like?

4. Ask students to share and discuss their observations of the fossil within their pair or group. Can they identify what the fossil is? Can they determine what kind of dinosaur it is? What can they tell about the dinosaur from examining the fossil? Students should record their predictions in the second column of their chart.

5. Based on their observation and description of each fossil, do students think it is a trace or body fossil? Instruct students to record their prediction and reasoning under the third column of their chart.

6. Have students exchange fossils and repeat steps 3-5 for each fossil.

7. Compare and contrast results with the entire class. Was it difficult to tell the difference between a body or trace fossil? Were students able to identify each fossil?

8. Hand out the fossil reference sheet created prior to the lesson. Ask students to identify each fossil (skull, eggshell, tooth, etc.), and whether it is a body or trace fossil. Have students explain the features or characteristics of each fossil that helped them identify it. Were they able to identify the type of dinosaur? If they are not able to identify the dinosaur, what observations can they make about each fossil? Can size, shape, or other distinguishing features help them learn about that dinosaur?

What’s Happening?
Fossils generally form when an organism is covered quickly after death by sediment. Over a very long time, the remains of the organism are gradually replaced by surrounding minerals that harden into rock. Scientists organize fossils into two main categories: body and trace fossils. Body fossils are the actual body parts of the original organism. Trace fossils are evidence of an organism’s activity or behavior. Paleontologists use fossils as clues to learn about how dinosaurs lived and what they looked like over 65 million years ago.
In this activity, students examine a set of fossils to determine whether each one is a body or trace fossil. Examples of body fossils include bones, teeth, and claws. Trace fossil examples include footprints, tooth marks, burrows, coprolites, nests and eggshells. A fossilized skin impression is considered a body fossil only if the impression was made at the time of the animal’s death; otherwise, it is considered a trace fossil.
By comparing both categories of fossils with similar modern day organisms, paleontologists are able to hypothesize a dinosaur’s inner biology, appearance and behavior. The teeth of a dinosaur can be analyzed to determine if it was a carnivore, herbivore or omnivore. The size and shape of dinosaur footprint tracks can help determine the size and behavior of a dinosaur, including how big it was, how it walked, how fast it ran, and whether it walked on four legs or two. Fossilized nests and eggshell fragments enable paleontologists to learn about a dinosaur’s life cycle and nesting behavior. Even fossilized feces (coprolites) can be analyzed to determine a dinosaur’s diet!
Topics for Science Class Discussion
• What tools or techniques do paleontologist use to find fossils?
• Which is found in greater abundance --trace or body fossils? Why?
• What do fossilized human remains tell us about the behavior or physical features of early humans?
Extended Activities and Links
Visit a local museum that features dinosaur fossils. Have students go on a scavenger hunt in the museum to find body and trace fossils on display.
Assign each student one particular type of dinosaur to research and present their findings to the class, using visual media such as slide presentations, poster boards or diagrams. Instruct students to explain what is known about that dinosaur and why.
Explore fun fossil facts and interactive games on the American Museum of Natural History’s OLogy website:
Follow in the footsteps of a paleontologist and learn the necessary procedures needed, from selecting a dig site to preparing a fossil for research and analysis:
View various types of fossils found in different geological time periods:§ionnav=main

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