PUTTING IT ALL TOGETHER
Paleontologists spend time searching for fossils, but when one is found, painstaking work must be undertaken to learn about the species. Students will perform a small-scale dig to learn what it is like to be a paleontologist.
Instructional Method: Experiment / Activity
Goal: To teach how paleontology digs develop and how information is gathered from the dig.
Objectives: Students will be able to:
- Define "paleontologist" and "paleontology" List the steps taken on a paleontology dig.
- Apply the steps to their own fossil dig using their representative fossil.
- Uncover buried "fossils" using appropriate tools and scientific methods.
- Piece the "fossil" back together and develop theories as to the "fossil's" natural history.
Day 1 - 1 hour, as well as 1 hour teacher time. Day 2 - 2 hours
- Popsicle sticks (enough for 15 per student or group of students)
- Tape (scotch works well)
- Markers (at least one per student)
- Examples of dinosaurs (pictures, models, etc.)
- Shoe boxes (one per student or group of students) OR a school sand box that can be protected over night
- Small shovels, brushes, or hammers
- String and stakes (if using a sand box)
Fossils are found throughout the world, often in very remote and inaccessible regions. A paleontologist's job requires time spent searching for the remains of life on Earth. Initial discoveries of fossils are perhaps the most exciting and easiest part of a paleontologist's job. The work really begins when the fossil is prepared and readied for transport back to the laboratory.
For large vertebrate fossils, tons of rock may need to be removed to begin the excavation process. In order to piece together this "lithic" (stone) jigsaw puzzle, detailed measurements, sketches, photographs and notes are taken from beginning to end to record all scientific data that can be gleaned from the excavation and removal process.
As portions of the fossil are uncovered, a clear hardening agent is sometimes applied to protect and strengthen the fossil. Fine pointed instruments and brushes are used in the final stages of excavation to clean off rock from the fossilized bone. In preparation for transportation, plaster and strips of burlap are applied to form a "cast" around the fossil and surrounding rock.The cast is carefully removed back at the laboratory.
Every aspect of the dig location, rock strata in which the fossil is found, orientation and amount of fossil material is recorded for use in reconstruction of the skeleton. Paleontologists spend hundreds of hours in preparing a fossil for scientific study and eventual display.
Complete skeletons are rarely found. Often scientists use imagination and deductive reasoning to put the pieces back together. Even incomplete fossils are important and can relate historical climate conditions of the animal's habitat. If a pine needle impression is found in the locality of , say, a T-rex, you can assume that the T-rex hunted or lived in a pine dominant forest. If only a tooth or claw is found of a raptor you know that it lived in the area.
In the following activity you will perform a small scale dig using popsicle sticks as fossil pieces. You will find the necessity of note keeping on your findings and the order it was found. Paleontology is fun but takes a lot of work once the fossil is found.
1. Day 1
- Have students lay 12 sticks side by side, flat on the table, to create a small canvas area for their artwork. Keep at least three sticks per group left over. Tape the sticks together at the top and bottom. This keeps the canvas together making it easy to draw. Turn the taped sticks over, so the tape is on the back of the drawing surface. (10 minutes).
- Using markers, have students draw a picture of a dinosaur or other ancient creature across the Popsicle sticks, so that each stick only contains a fragment of the drawing. (25 minutes).
- Remove tape from the sticks and jumble up the sticks. Each student should practice putting his/her fossil puzzle back together at least once. (10 minutes).
- Have each student write a one-page natural history of his/her fossil. For example: is it a carnivore, does it swim, does it walk upright? Emphasize that these theories about their fossil should come from clues in their picture. (15 minutes).
- Place sticks in a plastic bag with name and hand the bag into the teacher.
2. Teacher Time
- Remove two or three random sticks from each fossil puzzle, and replace them with blank sticks.
- Bury the fossil pieces in sand. Keep the fossils of one bag close together in the sand, making it relatively easy for the students to find and sketch.
3. Day 2
- Assign each student a shoebox or a marked space in the sandbox to perform a dig. (Use stakes and string to mark the spaces). For older students, this activity works best if the students are not digging their own fossil puzzle.
- Have the students carefully dig one inch of sand at a time. Students take notes on sand color, texture and sand grain size. (Older students are to graph and sketch the dig site at least once every inch - using the string to create a grid over the surface of the shoebox or sandbox.) (30 minutes).
- Once the sticks are found, without removing them from the sand, all students will sketch the sticks' arrangement. (30 minutes).
- Have students carefully remove the sticks from the sand and then lay them out on a table. Attempt to piece the drawing back together. There will be holes in the puzzle, because the teacher removed a few sticks and replaced them with blanks. Have students draw in the missing pieces using a color marker, different from the original drawing. (30 minutes).
- Once the puzzle is complete, have students develop a one-page natural history of this new animal. (30 minutes).
- Have students who created the fossil and the students who found the fossil compare the natural histories written. This will show some of the inconsistencies and constants in Dinosaur theories, as well as some of the things paleontologists have to deduce to make theories work. (30 minutes).
Why was it harder to put together the puzzle on Day 2? Do you think Paleontologists find fossils that are complete? How do Paleontologists fill in the holes in a skeleton? Would the kind of rock that a fossil was found in be important? What could a paleontologist tell from the kind of rock in which a fossil was found? Where can we learn more about Paleontologists?
Other activities that continue to develop fossil understanding and stratigraphy are found in Fossil Form and Function and Reading Chapters of Time.
1. Create some distraction fossils to be mixed into the stratified soil. Draw plants, eggs, or as you remove pieces of one student's fossil, mix them in to another students. This way the students will have to sort through the data to re-create the true fossil. Examples of real mixed up fossils are the brontosaurus vs. camerasaurus (sp?) and apatosaurus (sp?) as an example. (20 minute teacher time, 10 additional minutes activity time)
Discussion questions: Why is it harder to put the fossil together with these extra pieces? Where did these other fossils come from? What do they tell us about the environment in which the fossil was living / after it died? How do paleontologists sort though fossil pieces? How do paleontologists know that they have put the pieces together correctly? What if they discover later that they put the wrong head on a body? What happens?
2. Have each student choose a recorded dinosaur species and research the natural history of the creature. Re-do the activity, with each student drawing his/her species. Have the students bury their own fossils and trade dig sites with another student and repeat the activity. Have the student who dug the fossil write a short natural history. Have them compare the one they wrote with the actual natural history researched by the original student.
Discussion questions: Was the natural history that you made up similar to the one researched by the other student? What was different? Why do paleontologists think their version is more accurate than your version? What clues did paleontologists use to determine the natural history that we didn't realize were clues? Would those extra clues explain the difference?
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