FOSSIL FORM AND FUNCTION
Paleontologists look at fossil pieces and compare them to living animals of today to determine what that fossil animal did (how it ate, what it ate, where it lived, how it defended itself). This activity gives students random fossil pieces and allows them to construct an animal and determine what it did.
Instructional Method: Activity
- Teach students how paleontologists determine the function of fossil animals when they no longer are observable.
Objectives: Students will be able to:
- Describe how paleontologists figure out the function of fossilized animal parts.
- Explain how scientists estimate what a missing body part would have looked like
Setup: 30 min
Activity: 45 min
Discussion 20 min
- Pictures of skeletal fossils cut up into pieces (heads, legs, arms, fins, backbones, ribcage's, necks, tails, feet, teeth, etc.) PDF with images provided #1 page, #2 page, #3 page, #4 page, #5 page, #6 page, #7 page
- Sheets of paper
- Lined paper
- Crayons or pencils
Earth is about 4.6 billion years old. Life has been present on it for about 3.2 billion years. Paleontologists must determine how the past inhabitants of the earth fit into the total web of life and how they interacted with each other and their environment.
Fossils are found throughout the world. Each year new fossil discoveries help scientists better understand how life has changed on Earth. The process of change some animals went through can easily be seen as you look at the fossil record. This idea is further developed in the "Reading Chapters of Time" activity.
Fossils come from sea creatures, dinosaurs, plants and other ancient animals. Over 250,000 different kinds of fossils have been identified. After the death of an organism, the soft tissue is ordinarily consumed by scavengers and bacteria. The empty shell or bone is left behind to petrify within the gradually hardening sediment covering the animal part.
Paleontologists seek out tidbits of past life for study. Not all rock types preserve past information easily. Certain rock encases bone, shells, and plant matter better. These kind of fine-grained rocks are where most scientists look when searching for fossil remains. The problem with only looking in the good fossil preserving layers is that you do not get the diversity of animals that an environment can hold.
Finding specimens of many different animals of the past helps scientists to understand the diversity of animals we have today. Today's animals help scientists understand what animals of the past may have done or how they lived. Since we do not have anything but the hard parts of past animals, we look at modern animal skeletons and compare them to fossil remains.
We can easily determine which fossil animals were carnivorous by looking at teeth and claws and comparing them to those of modern carnivores. Comparing creatures of the past with modern animals of today tells us how past creatures may have lived. Flippers suggest the animal spent most of its life in the water. Flippers with knuckles suggest the animal temporarily spent some time on land. We can make this assumption by comparing the ancient animal with those animals of today with the same habits.
Although it is harder to determine what the outer portion of an ancient animal looked like, a lot can be inferred by studying the rock in which the fossil was found. If the rock contains fossilized tropical looking plants, the animal lived in a relatively warm environment, and so on.
Finding an intact or articulated fossil animal is rare, and when one is found, great care is taken to find all its pieces. With the entire skeleton, scientists have no need to infer what the whole skeleton looks like. When an incomplete skeleton is found, it is necessary to estimate what would be in the missing place.
Sometimes the missing bone is one or two vertebrae, or a missing limb. Many times the missing portion is a head, arms, legs or a tail. If just one of the legs is missing it is easy to guess what the other leg looks like. When a head is missing it is hard to infer what it would look like from the body alone. The same goes when both arms or legs are missing. Although parts are missing, much can still be learned about the fossilized animal remains. Scientists still compare those pieces to known animals or fossils and try to determine what role it may have played in the environment.
The following activity allows students to randomly select different animal pieces and place them together as if the pieces where found together. Some students will need to infer what the animal looked like complete because they will be missing pieces. From their animal body parts, students will determine where it lived, what it ate for food, how it interacted with the animals around it (scared other animals, was not bothered, etc.), and will draw a picture of it with skin and perhaps write a short story, like those of nature shows, about the animal.
- Copy pictures of a variety of fossil and modern day animal skeletons on paper.
- Cut the skeletons into pieces by way of heads, arms, tails, legs, ribs, backbones, teeth, feet, flippers, necks, claws, etc.
- Separate all heads, tails, etc. into their own bag of heads and the like. Place a random amount of oddly cut blank pieces of paper, with just the body part name on it, into the different bags.
- Discuss in class how biologists today are able to determine what animals of the past ate, how they lived, etc., by comparing them to similar animals of today. Explain that paleontologists use body structures to help them make these decisions. Sharp pointed teeth = meat eaters, broad flat teeth with ridges = plant eaters, etc.
- Pass out a blank sheet of paper to each student.
- Have students select out of the body parts bags; one paper from each bag.
- Have them glue the pieces on the paper forming an animal, leaving the blank spots blank. In the blank spots sketch what the body part may have looked like by comparing the available parts.
- If the unfortunate student draws three or more blank spots, that actually makes it easier for them. They will know less about their animal and have less to write because the information is not available.
- Using the body parts they have, have students draw the outside of their new animal on a separate sheet of paper. If one of their body parts was blank with only the name they need to guess what the body part would look like and include its characteristics in the outside drawing. (Example, they had a huge head and a huge body and were missing a neck, the student would need to draw a neck that would fit a huge head and body. The resulting neck would probably be thick.)
- After they have constructed the new animal and guessed the blank body parts, have students describe on a lined paper what the animal ate, where it lived, what it did for defense, or in other words how the animal lived. To do so students need to use what clues they received and list them in their animal description: teeth, feet, body part size, horns, lack of horns, etc.
Ask students how they would know if an animal was a carnivore or a plant eater? How would they know if the animal moved fast or slow? Where it lived? How it defended itself? What was the color of the animal's hair or skin? How did they know the animal's skin and hair color? Was it given in the skeleton pieces? Why did they determine the things they did for each one of their extinct animals? Did they use modern animals with the same characteristics to compare with their new animal? Was it warm blooded or cold blooded? Did it lay eggs, give birth to live young, or are they marsupials? How do they know?
Instead of using paper copies of skeletons you can cut plastic animals, dinosaurs, action figures, monster toys, etc. into pieces and place them into the different body parts bags. For blank pieces place random toys labeled blank on them. Use these 3-D body part pieces and follow the same instructions. You may want to have students place all their 3-D pieces in a sandwich bag instead of gluing them on the paper.
After kids have drawn their new animal and described its different characteristics as inferred from the "fossil" pieces, have them write a short story with their animal as the main character. The story needs to have a setting (habitat), and to describe what the animal ate and how it got that food, if it was afraid of other animals, how it defended itself from other animals, and what happened to it when it died (was it eaten, did it drown, was it quickly buried, were its bones randomly dispersed or was it all in one spot?).
Included National Parks and other sites:
Agate Fossil Beds National Monument
Alibates Flint Quarries National Monument
Dinosaur National Monument
Florissant Fossil Beds National Monument
Fossil Butte National Monument
Grand Staircase-Escalante National Monument
Hagerman Fossil Beds National Monument
John Day Fossil Bed National Monument
Petrified Forest National Park
Utah Science Core:
4th Grade Standard 4 Objective 1,2