TITLE OF LESSON PLAN:
The Fossil Record

LENGTH OF LESSON:
Two class periods

GRADE LEVEL:
9-12

SUBJECT AREA:
Animals

CREDIT:
Lisa Lyle Wu, science teacher, Thomas Jefferson High School for Science and Technology, Alexandria, Virginia.

OBJECTIVES:
Students will learn the following:

1. Because much of Earth was under the ocean millions of years ago, fossils of sea animals can be found in parts of the Earth that are now far above sea level, such as the area known as the Burgess Shale in the western Canadian Rocky Mountains.

2. This fossil record reveals a rich diversity of complex animal forms that lived in the ancient oceans known as the Cambrian Sea.

3. Many of the Burgess Shale fossils appear to be early ancestors of higher forms of life, including human beings, while others appear unrelated to any living forms.

MATERIALS:
Although students will choose the materials they need to build models and dioramas, they should limit themselves to materials that are available in your school or easily obtained.

Computer with Internet access

Books and articles concerning the fossil record, particularly the Burgess Shale

A list of the following Burgess Shale fossil forms: Anomalocaris canadensis, Opabinia regalis, Pikaia gracilens, Nectocaris pteryx, Aysheaia Peduncilata, Habelia optata, Paterina zenobia, Diaphora bellicostata, Leanchoilia Superlata, Canadaspis perfecta, Micromitra pannula, Naraoia compacta, Yohoia tenuis, Burgessia bella, Acrothyra gregaria, Sidneyia inexpectens, Hallucigenia sparasa, Waptia fieldensis, Olenoides serratus, Wiwaxia corrugata, Llingulella waptaensis, Amiskwia sagittiformis, Nisusia burgessensis, Fieldia lanceolata

Modeling clay and various other art materials for building models and dioramas

PROCEDURE:

1. Make sure students understand what basic background material they will need in order to proceed with the activities. Explain that the Burgess Shale is an area in the western Canadian Rocky Mountains discovered in 1909 by Charles D. Walcott and named for a nearby mountain, Mount Burgess. Because during the Cambrian geologic period, more than half a billion years ago, this area was under an ocean, the fossils of many sea animals have been found there. Because the animals, now fossilized in the Burgess Shale, were buried in an underwater avalanche of fine mud, they have been preserved in amazing detail. Many of them appear to be early ancestors of higher forms of life, while others appear unrelated to any forms on record since.

2. Allow time for students to use the materials you  have provided or the Internet to find out more about the Burgess Shale.  They will find extensive and fascinating information at the following Web  site: http://www.nmnh.si.edu/paleo/bshome.html.

3. Distribute the list of names of animals found in the Burgess Shale, and invite students, working individually or in groups, to select, research, and find a description of one or more animals. (You may want to see that all the listed animals are selected by one or more students.) The Web site cited previously will prove helpful in their research.

4. Have each student provide the following information in a brief written report on his or her animal:

-  How has the animal been classified?
-  What is the meaning of its name?
-  What ecological niche did it fill?
-  How was its anatomical form related to its function?
-  To which life-form would it be most closely related today?

5. After they have completed their research, have students build models of their chosen animals, based on what they have learned. Have them each create a diorama featuring their creatures in the ancient sea. Students should be sure to include information labels for each specimen.

6. Display dioramas around the room.

ADAPTATIONS:

Present students with a shortened version of the list of animals, limiting the list to those described on the Web site mentioned in Procedures. Instead of having students do research on their own, download these descriptions for them.

DISCUSSION QUESTIONS:

1. Many of the creatures of the ancient oceans had strange and complex body shapes. What explains their body shapes? Using creatures from the ancient oceans as examples, discuss how a successful body plan may exist virtually unchanged for hundreds of millions of years while others have become extinct.

2. Hypothesize reasons, motivations and explanations for the first sea creatures stepping out of the ocean. What do you think motivated the first creature to leave the ocean for land?

3. Why do you think scientists study ocean creatures so carefully? What do we learn from the evolution of organisms in the sea?

4. Brainstorm how life on our planet would differ today if a different set of organisms (not including vertebrates) had survived the Cambrian period.

5. Discuss the advantages and disadvantages of a terrestrial, or land, existence. What adaptations were necessary for life on land? How does it differ from life in the ocean?

6. Anomalocaris terrorized the ancient oceans, preying on all sorts of organisms. Yet some organisms, although smaller and not as strong, escaped this predator. Why do you think some organisms survived attacks while others didn't? What adaptations made it possible to evade Anomalocaris?

7. Discuss why some organisms may have existed but left no fossil evidence. Without a fossil record, how might scientists determine if the organsism ever existed?

EVALUATION:

You can evaluate your students on their group's research and models using  the following three-point rubric:

-  Three points:answers to all questions students  were asked about their animals; carefully constructed models that  closely match researched descriptions of the animals
-  Two points:answers to most questions students  were asked about their animals; models that fairly match researched  descriptions of the animals
-  One point:answers to few questions students  were asked about their animals; models that only vaguely match researched  descriptions
You can ask your students to contribute to the assessment rubric by determining criteria for evaluating models.

EXTENSION:

Animal Identification
Explain that the visual representation of life from Earth's early history is a combination of scientific descriptions by paleontologists and artistic interpretations made by artists and model makers. Provide students with some unidentified natural objects (parts of a whole) such as animal skulls or bones and ask them to visualize and sketch the whole animal. Ask students to list the clues they used to visualize the animal. When they are finished, show them a picture of the animal and tape up the pictures they made. Discuss the differences.

What Time Is It?
Have students research and discuss geochronology—the science of using geologic markers to date Earth's history. During the discussion, students should address the different methods used by scientists to establish time frames for geologic events, and they should explain why several methods may be used together to date a single fossil. For example, why might one fossil require the use of radiocarbon dating, the law of superposition (layering), and observations of reversals in Earth's magnetic field? Following research and discussion, students should choose one geologic dating technique and create a visual display detailing the procedure. On their display, students should include steps in the procedure for dating fossils.

SUGGESTED READINGS:

“Floor Show”
John R. Delaney.Sciences, August 1998.
This article presents research that suggests life may have gotten its start at the ocean floor in little “gardens of Eden”—ecological niches formed by volcanoes.

“The Unquiet Oceans”
Todd Preston. E: The Environmental Magazine, March/April 1997.
This feature article describes the contemporary threat of underwater noise pollution to sea creatures that have evolved to acquire highly sensitive hearing. The author explores the causes of this underwater stress. 

WEB LINKS:

Franklin Institute Science Museum
“Undersea and Oversee”: Collection of Web site resources and classroom activities about oceans. 
http://www.fi.edu/oceans/oceans.html

Learning from the Fossil Record
Presented by the University of California Museum of Paleontology. Contains lesson plans, activities, and essays for studying about dinosaurs and fossils in grades K-12. 
http://www.ucmp.berkeley.edu/fosrec/fosrec.html

Paleontology without Walls
Information and exhibits on three major and interrelated areas of paleontology: phylogeny (the family tree of life), geology, and evolution. 
http://www.ucmp.berkeley.edu/exhibit/exhibits.html

Burgess Shale Fossil Sampler
Information about the fossils located in the western Canadian rockies. Photographs of fossil specimens, drawings of primitive animals, and a Cambrian-era world map. 
http://www.nmnh.si.edu/paleo/bshome.html

Hooper Virtual Natural History Museum
Developed by the Earth Sciences Department, Carleton University, Ontario, Canada. An array of photographs, information, and current research regarding paleontology, including marine life. 
http://www.wf.carleton.ca/Museum/lobby.html

VOCABULARY:

Cambrian
Relating to the earliest geologic period of the Paleozoic era or the corresponding system of rocks marked by fossils of every great animal type except the vertebrates.
Context:
Hidden inside these craggy peaks are perfectly preserved Cambrian fossils. Cambrian is a geologic time zone starting approximately 570 million years ago.

extinction
The process of being eliminated.
Context:
The tiny wormlike creature escaped extinction.

niche
The particular role of an organism or species in its environment.
Context:
Tiny wormlike creatures secured an ecological niche in the ancient oceans.

notochord
A longitudinal, flexible rod of cells that, in the lowest chordates and in the embryos of the higher vertebrates, forms the supporting axis of the body.
Context:
The notochord is a long, stiff rod running the length of the body.

paleontologist
A scientist who deals with the life of past geological periods as known from fossil remains.
Context:
Paleontologists, scientists who study the fossil record, from across the globe visit this site.

ACADEMIC STANDARDS:

Grade Level:
9-12
Subject Area:
Earth science

Standard:
Understands basic Earth processes.

Benchmarks:
Knows how life is adapted to conditions on Earth.

Grade Level:
6-8, 9-12
Subject Area:
Earth science

Standard:
Understands basic features of the Earth.

Benchmarks:
(6-8)Knows that fossils provide important evidence of how life and environmental conditions have changed on Earth over time. 
(9-12)Knows how the evolution of life on Earth has changed the composition of the Earth's atmosphere through time.

Grade Level:
6-8
Subject Area:
life science

Standard:
Knows about the diversity and unity that characterize life.

Benchmarks:
Knows that animals and plants have a great variety of body plans and internal structures that serve specific functions for survival.

Grade Level:
6-8, 9-12
Subject Area:
life science

Standard:
Understands the basic concepts of the evolution of species.

Benchmarks:
(6-8)Knows that the fossil record, through geologic evidence, documents the diversification and extinction of many life forms. 
(9-12)Knows the history of the origin and evolution of life on Earth.

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