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As part of our annual unit on fossils and geologic time, our students explore the role of paleontologists in discovering our Earth's history as they dig for the bones of an "ancient" critter. Throughout the dig, students work as research teams to collect information as they excavate a site to find bones. Once the excavation process is completed, teams reconstruct the bones to form an “ancient” creature and determine the cause of its death, relative size, and a description of its habitat.
Our students gained much more from this project than we had ever imagined. Much needed process skills were used each day. Our students have an understanding of paleontology that could never be learned from a textbook and lectures. Students discovered that science is more than a bunch of facts! Science is exploring, investigating, and discovering the world around them!
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Preparing for the Dig
To prepare each site, we constructed a 2' by 2' container from plywood and 2” x 4” lumber. Each site was sealed with silicone, painted, and marked with grid lines (see general site description (pdf)) to help students detail the location of their finds. The “sandstone” was a mixture of 1 part sand mortar to 2 parts sand. You will want to experiment with your materials to get the best mixture.
Each site contained the bones from a bird skeleton. You can obtain bird skeletons from a variety of sources - hunters, science supply stores, or your own dinner table! To prepare the bones, we boiled them to remove most of the gunk. After the boiling process, the bones were scrubbed with a brush and given a quick soak in bleach water. The bones were allowed to air dry for several days.
After placing a thin layer of the sandstone mixture in a site, related bones (wings, legs, or neck) were placed together, while others were scattered to recreate a skeleton from a critter than had been prey for larger animals. In some years I have used leftover bones and created sites that contained the remains from more than one animal to provide an extra challenge during reconstruction. Once all the bones were in the site, they were covered with the remaining sandstone mixture.
Each site was provided with a unit binder, which included background information (pdf), safety rules/inventory list (pdf), general site description (pdf), daily checklists (pdf), job charts (pdf), basic journal information (pdf), several journal pages (pdf) for all the teams, and four site maps (pdf) (one for each quadrant.) A geologic time scale and sample skeleton diagrams from a local museum were also included in the binder. Excavation tools were provided for each site and included tooth brushes, dental picks, wooden picks, metal chisels (screwdrivers), spoons, shovels (plastic butter tubs), small hammers, debris buckets (old 5 gallon buckets), and strainers. Each site was also provided with a cardboard box referred to as the bone box.
Dig teams excavated one quadrant of a site and were required to communicate with other teams at their site during the process- similar to “real life” excavation work. The journals, site maps, and inventory lists in the unit binders helped them communicate with teams in other classes. We utilized a digital camera to keep a record of each team's progress throughout the project (excavation and reconstruction) which helped them share their work with other teams.
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Prior to the first dig day, students were instructed on proper excavation procedures (Excavation Procedure worksheet (pdf) as they completed the dig procedure page, such as how to make a journal entry, tips on drawing diagrams on the site maps, and the proper procedure for tagging the bones. Students searched the unit binder for most of the information for the worksheet. Other information, such as site maps and tagging, was provided during the class discussion.
To allow every student a chance to participate, we provided teams with a job rotation schedule. Students rotated through two jobs: the investigators (excavators) and the reporters (recorders). This rotation allowed every student to be a productive member of the team. One team member was designated as captain. The captain reported progress reports to the teacher, made sure that everyone had their job assignment, and filled in if a team member was absent.
On the first dig day, team captains assigned jobs outlined in the job charts and the students started the excavation. They were directed to excavate 1/4 of their quadrant each day. When investigators discovered a bone, it was entered in the daily journal inventory and detailed on the site map before it could be removed from the site. After the bone was removed, it was tagged by site code and number (such as SS-1 for Sandstone Survey, 1st bone) and placed in a bone box for their site. Daily updates were provided for the teacher by team captain. The updates described their team's activities for the day and their plans for the next day. All team members were responsible for cleaning their area each day.
NOTE: Students were required to wear safety goggles during excavation. Proper techniques and tips for using tools (to limit the need for first aid) were demonstrated the first dig day.
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After completing excavation, students were allowed time to reconstruct their critter and complete a final analysis (pdf) including the critter's size, habitat, cause of death, and skeletal diagram. To help them reconstruct the skeleton, basic diagrams (from a local museum) provided some assistance, but final identification was left up to the teams. A digital camera allowed teams to communicate their reconstruction ideas to teams in other hours.
Most teams concluded the critter was a bird since the bones were hollow and similar to bones in the bird skeletons. Due to the sandstone matrix, teams concluded the critter lived near water. Many teams speculated that the critter died when it was killed for food by a larger animal or group of animals - called the “scavenged critter theory”. The missing pieces of the skeleton were believed to have been washed away by a stream or river or carried off by predators. The reconstructed skeletons did not fully resemble a true skeleton as it was difficult to get a 3-D model. Many teams were able to identify a variety of bones to reconstruct legs, wings, and/or chest areas. The absence of skull bones was easily dismissed by the “scavenged critter theory” described above.
NOTE: Students were not informed of the critter’s real identity as we felt the process of identification was more important than just getting the correct answer. Too often our students are focused on getting the right answer rather than exploring all the possible ones. Teams were required to provide evidence (from the dig journal & site map) to support their claims. For instance, they couldn't claim their critter was 6 foot tall, when the leg bones were only 6 - 8 inches in length.
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Digging into Science Share-A-Thon
Lauren Teather, a teacher in Africa, has challenged her students with the "Digging into Science" project for the past two years. She has provided the worksheets she uses with her students. Thanks for sharing, Lauren!
• digjobdescriptions.doc - Lauren changed the job of captain to "researcher". She has 3 sites called Jurassic, Triassic, and Cretaceous. The researcher's job is to put together information describing the animal life, plant life, and major evolutionary events that occurred during the geologic time period for the site. She has the students rotate through the jobs for 3 days, which gives each student a chance to assume the roles of investigators, recorders, and researchers.
• digjournalwriting.doc - Lauren modified the Daily Journal page (pdf) into a set of questions that the students must answer each day.
• diggrpassessment.doc - Lauren uses this page to evaluate the group during the dig process.
• digfinaleval.doc - Lauren's version of the Final Analysis (pdf).
• digfinalportfolio.doc - This page describes the requirements for the Final Portfolio, which includes inventory sheets, journals, site maps, and other documents from the dig and research.
• digassessment.doc - Lauren uses this page to evaluate the group's efforts as well as individual students.
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Activities, lessons, & worksheets available on any page of this web site are intended for use by a single teacher in his/her classroom or to share at educational conferences. Reproduction for commercial use or profit is not permitted without the express written consent of Mrs. Tracy Trimpe. Visit my Frequently Asked Questions page for more details!