Preparation: Before class on Day One prepare the puzzle pieces. Cut them out and place them in an envelope. Remove a few pieces of the puzzle. This is to replicate the experience of a paleontologist who may not have "all the pieces of the puzzle" to fill in the whole picture of a new species.

Day One

1. On the board write the title of the lesson, "The Missing Piece: A Tale of a Tail". Divide the class into groups of two. Provide each group of students with an envelope that contains Student Handout 1-The Missing Piece (Puzzle Pieces). There are two puzzle choices provided. You might give each group the same puzzle or different ones. Be sure to prepare the puzzles ahead of time by cutting them into pieces and removing several parts that will challenge students as they try to discover the image that is on each puzzle. Direct the students to try to solve the puzzle. They should be given approximately 5 minutes to solve the puzzle. Students will then complete Student Worksheet 1-The Missing Piece . Discuss the answers as a class.

2. Think-Pair-Share: In the same groups of two, have students complete Student Worksheet 2-Historical and Scientific Experts. Students should use the symbolic clues on the graphic organizer to identify what each expert studies in their field. Discuss the answers as a class.

3. Ask the students, "How are the jobs of historians, scientists, paleontologists, and other scientific experts like a puzzle?"

4. Explain to the students that history and many scientific fields share many commonalities. To identify the facts, the truth, or the story, many things and/or ideas must be put together. However, often there are missing pieces that make this task challenging and can often lead to mistruths. It may be days, months, or years until the truth can be found. Many scientists, inventors, and historians had to try many times to identify the facts. Sometimes time, technology, and different perspectives from other individuals are needed to unfold the real story. Does this bring cause to criticize those who failed to locate the "missing piece" or were their efforts the beginning of a great discovery?


5. Use an LCD projector or distribute Leidy with Bone of Hadrosaurus foulkii, 1858. Students should analyze the photo and complete Student Worksheet 3-Joseph Leidy with Bone. Discuss the answers as a class.

6. On the board write the words "Elasmosaurus platyurus Cope". Ask the students what "Elasmosaurus platyurus Cope" might be. Explain that Edward Cope is the "author" of "The Missing Piece: A Tale of a Tail".

7. Share the Background Information on the historical context of the dig for Elasmosaurus platyurus Cope. This information can be found in the Background Information for Teachers section of this lesson plan. It contains an explanation of how our country was pushing westward. It was through this movement that the fossil bones of Elasmosaurus platyurus Cope were discovered.

8. Distribute Student Handout 2-Paleontologist Biographical Background. This handout contains a photo and brief biographical information about the key paleontologist involved in the "Elasmosaurus platyurus Cope" case. Review this information as a class. Students should keep this handout accessible for future reference.

9. Homework: Distribute:

Skeleton Diagram of Elasmosaurus platyurus Cope (short neck)
Skeleton Diagram of Elasmosaurus platyurus Cope (long neck)
Illustration of Elasmosaurus platyurus Cope with Dinosaurs (short neck)
Illustration of Elasmosaurus platyurus Cope with Dinosaurs (long neck)

Students should analyze the primary sources and answer the questions on Student Worksheet 4-Which End is the Tail?



Day Two


Revisit the sources given for homework. As a class, discuss the answers to the questions on Student Worksheet 4-Which End is the Tail?

You may wish to refer to Teacher Guide to Student Worksheet 4-Which End is the Tail?.

Divide the class into groups of four. The key question for each group to answer is, "Which end is the tail?" Students will be permitted to use the images they were given for homework. They will also be provided with Student Handout 3-Paleontologist Views on "Elasmosaurus platyurus Cope". This handout contains excerpts and modifications from the following source documents:

Edward D. Cope, "Remarks on a new large enaliosaur," Proceedings of the Academy of Natural Sciences of Philadelphia 20 (March 24, 1868), 92-93.

Joseph Leidy, "Remarks on Elasmosaurus platyurus," Proceedings of the Academy of Natural Sciences of Philadelphia. Vol. 22, (1870), 9-10.

Each group of students will complete Student Worksheet 5-Solving the Dinosaur Mystery. This worksheet contains a list of questions that is to be used by the groups as they analyze images and documents of Elasmosaurus platyurus Cope. Each group should share their final conclusion with supporting detail to the class.

You can use Teacher Guide to Student Worksheet 5-Solving the Dinosaur Mystery as a reference when students share their conclusions.

4. Distribute and instruct students to complete the Student Worksheet 6-Publishing Your Findings Students will write a persuasive letter to a popular magazine like National Geographic or Science Discovery in which they will do the following:

A. Describe the Elasmosaurus platyurus Cope. Include facts on its habitat, how it survived, how it moved, etc
B. Identify which end of the Elasmosaurus platyurus Cope is the tail
C. Incorporate several facts to support their conclusion
D. Include opinions to support their conclusion
E. Answer the question "Why is the job of paleontologist like Cope and Leidy, as well as other historical and scientific experts challenging?"

5.After students have completed the assessment, share and discuss Anterior cervical vertebrae, Elasmosaurus platyurus Cope, 1868. Identify the axis and atlas as "the missing piece", the piece which Cope had missed or overlooked. Ask the students to view the photograph and try to identify what it is. If they cannot, have them guess based upon their readings. Explain that Cope had not noticed the atlas/axis at what he thought was the tip of the tail.

6. Ask the students to define what the atlas and axis are. Have students' associate previous meanings of the word.

a. Axis-a straight line which something else turns. (Think of a wheel.) Second vertebrae which holds the atlas.

b. Atlas-the first vertebrae that supports the head. (Students may know an atlas as a group of maps of the world. Ask how maps got their name. The origin of "Atlas" for map: A Titan named "Atlas" was punished to carry the world on his shoulders for undermining the Greek god Zeus. He was drawn on one of the first maps, hence a book of maps became known as an atlas. Since Atlas supported the world on his shoulders, what do you think the atlas bone would support? [The head.]

7. Finally, ask the students where the head should go? The head should go on what Cope thought was the tip of the tail. The tail was actually a very long neck! Mystery solved! At this time you could also share Cope's Restoration of the Giant Enaliosaurs, Elasmosaurus platyurus. This source illustrates the correct structure of Elasmosaurus platyurus.