Activity 2: Paleo Dig
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:
Day 1 - 1 hour, as well as 1 hour teacher time. Day 2 - 2 hours
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
2. Teacher Time
3. Day 2
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
Utah Science Core:
4th Grade Standard 4 Objective 1,2