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Name:
Date:
Burgess Shale Fossils!
Fossils: Definition and Formation
-Fossils: ______________ or __________ ________________ of a plant or animal preserved in rock.
-Fossils are formed when two conditions are met: 1._____________________________________ and
2. _____________________________________. The rarity of both of these conditions being met means
that the __________ ___________ does not accurately represent the history of life on Earth.
Burgess Shale Fossil Formation
-___________________ fossils are found in the Burgess Shale from the ___________________ period.
-Continental Drift says that Earth’s _________________ move on top off its surface because of the
movement of ______________ _________________. This explains how the Burgess Shale is now found
in the Rocky Mountains.
-The _________________ ___________________ was a period of rapid evolution between 545 and 525
million years ago in which all the basic body plans of modern animals were present.
Burgess Shale Fossils
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-Take a careful look at this world map and get dis-oriented! Does China (3) lie due north of
Africa? Is China really that small! Why is Africa northeast of Europe, and since when is
Europe way below the equator, two-thirds of the way to the South Pole? According to current
interpretations of the paleogeographic record this is how the continental blocks were arranged
about one-half billion years ago - before plate tectonics (still an active process!) rearranged
them into today's familiar pattern.
-Several numbered sites on this map show some of the areas where Burgess Shale-type fossils
have been found. In the center of this reconstruction, the North American continental block is
turned 90 degrees clockwise, lying close to the equator. While it is not shown here, much of its
central portion lies under water, flooded by the immense, inland Sauk Sea (named after Sauk
Center, Minnesota, an ancient shore area). Parts of what will become Eastern Canada and New
England are still stuck onto part of Europe to the south, while South America is still nestled
against Africa.
-Because of North America's location, the sea shores at the Burgess Shale site in Canada are
warm and tropical. Coral reefs are common.
-Later, the separate continental parts shown here will move together, and during the Paleozoic
era the Permian period will form one huge landmass - Pangaea. That, in turn, during the
Mesozoic will break into two masses, Laurasia and Gondwanaland.
-Still later, about 100-140 million years ago, when the mid-Atlantic rift becomes active, the
North American plate and Europe will be shoved apart. On the other side of our continent, the
Pacific plate will be shoved into and under our west coast.
-When that plate moves toward and sinks under the North American continental block, it will
carry along various chunks of off-continental fragments to be scraped and "plastered" against
the western coastal regions as the plate sinks beneath. When this land is added to the coast, it
will push the Burgess Shale location even further from the sea. (Now, it's about 400 miles
inland.) Simultaneously, when the Pacific plate sinks beneath the coast, its (lighter) added bulk
will "float" the Burgess Shale site miles high to its present location.
1. a) Where was the Burgess Shale located 500 million years ago? Two descriptors are necessary (2
Marks)
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b) Where is the Burgess Shale located today? Through what process was it moved? (2 Marks)
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Burgess Shale Fossils
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-The diagram reconstructs the Burgess Shale site as it would have looked millions of years ago.
-Today, some of these underwater locations have become Wapta, Dennis and Stephen mountains
found near the resort town of Banff.
- It is easy to imagine how an avalanche of fine mud sliding down the algal reef could have
swept away animals living in the shallow waters and buried them at the reef’s base.
-The hard parts of these unfortunate reef animals were preserved as fossils through a process
found at many other Cambrian Period sites, but at the Burgess Shale the fine mud of the reef also
penetrated and filled all available spaces within the animals. In this manner the shapes and
locations of the animal’s soft parts were also preserved. This is an extremely rare event and
makes the Burgess Shale’s fossils extremely valuable to paleontologists!
Burgess Shale Fossils
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An interesting, busy place! Prominent at top right the head end of Anomalocaris is shown about
to chomp on Waptia. Lower right shows Ottoia ready to pounce on a meal of Haplophrentis.
Then, just to its left, Pikaia swims above the substrate showing its flattened tail. Just below
center stage, Opabinia's trunk-like snout has caught Burgessochaeta, a bristle worm relative of
Canadia (not shown). There, to its left, Hallucigenia and Wiwaxia scurry along just in front of a
very large Sanctacaris. At center left, Aysheaia dines on the sponge Vauxia while at lower left,
Microdicyton nibbles away on a companion sponge. Above Opabinia, two Naraoia move along
leaving long tracks in the bottom sediment. The spiny, vase-like sponge to their left is Pirania
with two attached Nisusia.
2. What is so special about the Burgess Shale fossils? Hint: there are two reasons (2 Marks)
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3. What factors contributed to the preservation of the Burgess Shale animals as fossils? (2
Marks)
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Burgess Shale Fossil Analysis
a) Using the tools available (hand lens, pencil, fossil diagrams) and the Appendix VI Student Handout
attempt to determine the characteristics present in individual Burgess Shale fossils. Record this in Table
1: Burgess Shale Animals.
b) Using these characteristics and the information on modern animal groupings found in the Appendix VI
Student Handout attempt to determine if there are any resemblances between Burgess Shale fossils and
the animals we see around us today.
c) Based on shared characteristics between the Burgess Shale fossils and modern animals attempt to
classify the fossils into a phylum and class. Note: This is not possible for all of the fossils!
d) Answer the Discussion questions using the information you recorded in Table 1: Burgess Shale
Animals.
*To help you with this project you should explore two websites:
a) The Burgess Shale site by Parks Canada/Royal Ontario Museum. This has computer animated videos,
diagrams, photos and more of all of our samples!
http://burgess-shale.rom.on.ca/en/fossil-gallery/list-species.php
b) Berkley Evolution website looking at the Burgess Shale fossils:
http://evolution.berkeley.edu/evolibrary/article/_0_0/cambrian_01
Burgess Shale Fossils
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Table 1: Burgess Shale Animals (10 Marks)
#
Animal
Marrella
splendens
Characteristics
Resembles
Phyla
Class
1
17
Pikaia
6
Canadaspis
perfecta
19
Hallucigenia
11
Wiwaxi
corrugate
8
Anomalocaris
Canadaensis
Burgess Shale Fossils
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#
Animal
Leanchoilia
superlata
Characteristics
Resembles
Phyla
Class
3
4
Naraoia
compacta
7
Ottoia
prolifica
5
Sidneyia
inexpectans
Discussion Questions (15 Marks)
1. Examine any animals you thought belonged to Phylum Arthropoda. Name three characteristics that
these Arthropods have in common. (3 Marks)
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2. What morphological feature do all Burgess Shale animals studied have in common? Hint: Think about
where they live! (1 Mark)
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3. Which animals were difficult to classify? Why? (2 Marks)
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4. Can you think of a reason why our modern classification system cannot accommodate the morphology
of the animals you mentioned in Question 2? Hint: Your answer should mention the role of extinction in
evolution. (2 Marks)
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5. Give three reasons why the Burgess Shale fossils are so important to scientists that they are designated
a part of a UNESCO World Heritage Site. (3 Marks)
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6. Does the Burgess Shale provide evidence for the Gradual Change model of evolution of the Punctuated
Equilibrium model of evolution? Explain your answer. (2 Marks)
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7. What improvements could be made to this lab to make it more effective? (2 Marks)
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Fossil Inventory:
1. Marrella splendens
2. Burgessia bella
3. Leanchoilia superlata
4. Naraoia compacta
5. Sidneyia inexpectans
6. Canadaspis perfecta
7. A+B Ottoia prolifica
8. Anomalocaris Canadensis
9. Isoxys acutangulus
10. Selkirkia columbia tube
11. Wiwaxia corrugate
12. Pirania muricata
13. Vauxia gracilenta
14. A+B Hyalithes carinatas
15. A+B Diraphora bellicostat
16. Ogygopsis klotzi
17. Pikaia
18. Peytoia
19. Hallucigenia
Burgess Shale Fossils
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