field trip to the field museum and shedd aquarium · timescale, map, and summary of major events in...

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Name: ________________________________ Field trip to the Field Museum and Shedd Aquarium Field Museum At the Field Museum, we will focus on one major exhibit, the Evolving Planet exhibit, located on the second floor of the Field Museum. This field trip guide is selfpaced, and you can move at whatever pace and in whatever order you find most convenient. You will find useful resources, including a timescale, map, and summary of major events in Earth history, later in this field trip guidebook. Goals for this portion of the field trip include the following: Gain a better understanding of the geological timescale and major events in the history of life, including the origin of life, mass extinctions, and major evolutionary transitions. Gain firsthand experience with the major biological organisms that constitute the fossil record, especially as informed by the major evolutionary faunas and floras. Observe fossils and appreciate the ways that paleontologists use them to reconstruct ancient organisms and communities. Pay attention throughout the exhibits: Murals and reconstructions As you enjoy the exhibits, pay special attention to the original and historically important paintings by Charles R. Knight, done in the early 1900s. Knight was one of the first and most important painters of paleontological subjects, and gained widespread fame for his works published in National Geographic and other venues. There are murals and reconstructions by other artists and museum exhibit staff members, as well. Many of these include reconstructions of individual animals, such as dinosaurs, invertebrates, and other plants and animals. Although these are artistic installations, they are often done with significant advice from scientists to ensure that they are as realistic and scientifically accurate as possible. 1. Given your knowledge of the history of life, note which murals, exhibits, and reconstructions are the most scientifically accurate. 2. Which ones (if any) strike you as particularly full of errors? In other words, critique the scientific accuracy of some murals and reconstructions.

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Page 1: Field trip to the Field Museum and Shedd Aquarium · timescale, map, and summary of major events in Earth history, later in this field trip guidebook. Goals for this portion of the

Name: ________________________________ 

 Field trip to the Field Museum and Shedd Aquarium 

 

Field Museum At the Field Museum, we will focus on one major exhibit, the Evolving Planet exhibit, located on 

the second floor of the Field Museum. This field trip guide is self‐paced, and you can move at whatever pace and in whatever order you find most convenient. You will find useful resources, including a timescale, map, and summary of major events in Earth history, later in this field trip guidebook. Goals for this portion of the field trip include the following: 

• Gain a better understanding of the geological timescale and major events in the history of life, including the origin of life, mass extinctions, and major evolutionary transitions. 

• Gain first‐hand experience with the major biological organisms that constitute the fossil record, especially as informed by the major evolutionary faunas and floras. 

• Observe fossils and appreciate the ways that paleontologists use them to reconstruct ancient organisms and communities. 

 Pay attention throughout the exhibits: Murals and reconstructions 

As you enjoy the exhibits, pay special attention to the original and historically important paintings by Charles R. Knight, done in the early 1900s. Knight was one of the first and most important painters of paleontological subjects, and gained widespread fame for his works published in National Geographic and other venues. There are murals and reconstructions by other artists and museum exhibit staff members, as well. Many of these include reconstructions of individual animals, such as dinosaurs, invertebrates, and other plants and animals. Although these are artistic installations, they are often done with significant advice from scientists to ensure that they are as realistic and scientifically accurate as possible.  1. Given your knowledge of the history of life, note which murals, exhibits, and reconstructions are the 

most scientifically accurate.      2. Which ones (if any) strike you as particularly full of errors? In other words, critique the scientific 

accuracy of some murals and reconstructions.     

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 Pay attention throughout the exhibits: Fossil specimens 

While you view the exhibits, also be on the lookout for real fossils. The Field Museum is exceptional, if not singularly unique, because it places type specimens on display. (Type specimens are the fossils considered the best preserved and displaying the most diagnostic features of newly described species. In other words, type specimens are those priceless and scientifically most important specimens photographed in the original scientific publications!) In most museums, such specimens are locked away in padlocked drawers, far from public exposure, and only viewable by specialist paleontologists.  3. Identify as many type specimens as you can throughout the exhibits. Type specimens are often 

designated with specialized terms such as holotype, paratype, lectotype, and neotypes.        4. See if you can identify examples of each of the following modes of preservation.  

Mode of preservation  Exemplar species  Type of plants/animals 

Unaltered     

Casts and molds     

Permineralization     

Recrystallization (Pyritization, silicification, etc.) 

   

Carbonization     

  

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 Pay attention throughout the exhibits: Fossil specimens You know that life has experienced five major mass extinctions, and some scientists think we are experiencing a sixth currently because of anthropogenic influences. As you travel through the exhibits, pay attention to the mass extinctions and fill out the following table.  

Mass extinction 

Era  Period  Age (m.y.a.)  % of life lost  Main cause 

           

           

           

           

           

 5. What is the argument for a sixth, current extinction?    Precambrian 6. How old is Earth?   7. How much of Earth’s history is represented by the Precambrian?   8. Describe a few of the fossils typical of the Precambrian.   

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Cambrian evolutionary fauna 9. What are some of the major fossiliferous groups represented in the Cambrian evolutionary fauna?  

    

10. How did Cambrian communities exist ecologically? (in other words, describe the typical ecological strategies found in Cambrian communities.) In what way is the ecology quite different than found in the Ediacaran communities of the Precambrian?     

11. What geological formation does the main diorama reconstruct? Where were the fossils for this formation discovered?     

12. Was there any life on land during the Cambrian?     

13. Describe what Earth was like during the Cambrian. (For example, where were continents located? What was sea level like? What was the climate like?) Where was Illinois located at this time? 

    Paleozoic evolutionary fauna 14. What are some of the major fossiliferous groups represented in the Paleozoic marine evolutionary 

fauna? How did they live (in other words, describe the typical ecological strategies found in Paleozoic communities.)        

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15. What were some important innovations in the history of vertebrates during the Paleozoic? Which of these innovations were important to terrestrialization? 

     16. What was life on land like during the Paleozoic? What were some important innovations during this 

time?      17. Describe what Earth was like during the Paleozoic?  Where was Illinois located at this time? 

    

Silurian fossil reef diorama 18. Deposits of ancient coral reefs occur in Silurian rocks under the city of Chicago (which we will visit 

during our second field trip). By looking at these fossilized coral reefs, what can we say about the environmental conditions during the formation of these ancient reefs?     

19. What organisms composed the primary constructors (the building blocks) of the reef structure?     

20. What organisms lived attached to this reef structure?     

21. What organisms swam near or crawled along the reef?      

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Carboniferous coal forest 22. The great coal forests of the Carboniferous Period were composed of plants that are very different 

from trees alive in modern forests. Describe these ancient plants and how they are different from modern plants.      

23. What animals lived in these coal forests? What is unique about these animals? (Scientists are unclear why these animals are so unique, and there are two hypotheses. The first was that there were no larger animal predators, which allowed insects to evolve to enormous body sizes to take advantage of the wealth of food. The second is that the incredible amount of oxygen—the highest ever known in Earth history—allowed greater respiratory efficiency, which allowed larger body size. Why might the Carboniferous have had such high oxygen levels?) 

     

24. Toward the end of the Carboniferous Period, the continents continued to drift together, eventually colliding, to form the supercontinent Pangaea. Describe what happened as Africa collided with eastern North America. What prominent features were formed in North America at this time? 

     

Permian 25. What is Pangaea? What lines of evidence support the existence of Pangaea?     26. Toward the end of the Paleozoic, Earth's climate began to change dramatically. Describe this 

climate, and describe how fossil plants can be used to study climate.. (You will view more discussion of the connection between climate and plants in the Cenozoic exhibits, too.) 

      

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27. Draw and label the parts of the amniotic egg. Why was the evolution of this type of egg so important to the evolutionary success of early tetrapods? Can you think of a connection between the evolution of the amniotic egg, Permian climate, and the evolution of plants and animals?        

Mesozoic portion of the Modern evolutionary fauna 28. What are some of the major fossiliferous groups represented in the Mesozoic portion of the Modern 

marine evolutionary fauna? How did they live (in other words, describe the typical ecological strategies found in Mesozoic communities.)      

29. What was plant and animal life on land like during the Mesozoic? What were some important innovations during this time? 

    30. Describe what Earth was like during the Mesozoic? Where was Illinois located at this time? 

    

31. The first dinosaurs evolved in the Triassic. Describe what the earliest dinosaurs looked like. What did they eat? How big were they? Where are their fossils found? 

    

32. What are angiosperms? What is coevolution? Name several organisms that coevolved with angiosperms and explain why. 

    

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Cenozoic portion of the Modern evolutionary fauna 33. What are some of the major fossiliferous groups represented in the Cenozoic portion of the Modern 

marine evolutionary fauna? How did they live (in other words, describe the typical ecological strategies found in Cenozoic communities.)     

34. What was plant and animal life on land like during the Cenozoic? What were some important innovations during this time? 

    35. Describe what Earth was like during the Cenozoic? Where was Illinois located at this time? 

    

36. Define browsing and grazing. Give examples of browsing mammals and grazing mammals. How are their teeth different and why do these differences exist? 

    

37. Describe Earth's climate during the Cenozoic. How do evolutionary changes in plants and animals mirror these climate changes? (Pay particular attention to how the evolution of grass, primates, birds, and horses all show similar evolutionary trends.) 

    

38. Describe the age, location, depositional environment, and other aspects of the Green River Formation, an important Lagerstätten. What plants and animals are preserved in these deposits? 

    

39. What group gave rise to the hominids? How do we know? Who is “Lucy” and why is she an important fossil? (You may wish to go back to the previous room and examine the primate tree of life.) 

  

 

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40. What are ice ages? How many ice ages have there been on Earth? Was the most recent ice age the most intense? 

     

Shedd Aquarium At the Shedd Aquarium, we will focus one major exhibit, the Wild Reef exhibit, located as a 

special exhibit in lower level of the Field Museum. This field trip guide is self‐paced, and you can move at whatever pace and in whatever order you find most convenient. You will find useful resources, including a map later in this field trip guidebook. Goals for this portion of the field trip include the following: 

• Observe living members of important fossiliferous groups. 

• Understand the modular lifestyle of asexual organisms and the importance of spatial competition for such organisms. 

• Observe the structure and function of modern coral reefs, paying particular attention to the important ecological roles of the reef inhabitants. 

  

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Pay attention throughout the exhibits: Fossils and their living relatives While you view the exhibits, be on the lookout for living relatives of fossils. 

 41. What are the major characteristics that allow organisms to be fossilized? Why is the marine fossil 

record so much better than its terrestrial counterpart?     42. See if you can identify living examples of each of the following groups of animals.  

Fossil group  Modern representatives 

Sponges (Poriferans)   

Corals, anemones & jellyfish (Cnidarians) 

 

Trilobites, insects & crustaceans (Arthropods) 

 

Brachiopods & bryozoans   

Cephalopods   

Snails (Gastropods)   

Clams, mussels, scallops & oysters (Bivalves) 

 

Crinoids & urchins (Echinoderms) 

 

Sharks, fishes & mammals (Vertebrates) 

 

  

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The basic building blocks of coral reefs The basic coral animal is called a polyp, and 

is similar to a sea anemone inside a hard, calcareous skeleton called a theca. Corals feed using poison‐barb‐tipped cells called nematocysts along their tentacles, which they use to capture small animals (zooplankton) and then place in their mouth (which also serves as their anus). When disturbed or not feeding, the polyps can retract into their skeleton. 

Many reef‐building corals, called hermatypic corals, also have unicellular algae called zooxanthellae that live within the epithelial tissue of the polpy. These endosymbiotic algae allow such corals to, in essence, photosynthesize. But this lifestyle requires that these corals grow quickly to live close to sea level where the sun's intensity is greatest. Because of this dual feeding ability, most coral's photosynthesize during the day and hunt with their tentacles at night. 

Corals are colonial animals that reproduce asexually, cloning themselves along the margin of the colony. Because the tropical ocean is often nutrient poor and there is tremendous competition for food (and sunlight), real estate is perhaps the most important factor for survival of corals. Spatial competition is intense! 

43. What kind of mineral are coral skeleton's built from? When reefs are preserved as sedimentary rock, what would we call this rock?     

44. Describe the mutualistic behavior of the hermatypic (zooxanthellae‐bearing) corals. In what way does the coral polyp benefit? In what way does the zooxanthellate algae benefit?      

45. What important requirements or strategies does this mutualism force the coral to enact?     

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46. Where are most coral reefs located? What factors appear to be most important for a reef to flourish?       

Modular design of coral reef structures Corals are modular organisms, which 

means they grow as asexual, connected, colonial modules that build large structures. Other modular animals include bryozoans, sponges, and a variety of other animals that have helped build reefs throughout the Phanerozoic. (Note that such reefs are not coral reefs, but instead sponge reefs, bryozoan reefs, etc.) 

47. What might be some benefits and costs of such modular lifestyles? 

        

There are often pieces of coral on the sea floor near coral reefs. This can happen because of hurricane and wave damage, which can place immense pressure on coral reef structures. Damage can also occur by fishes and other animals (especially parrot fishes and urchins) that bite off pieces of coral during their feeding. 

48. What happens if a coral breaks or falls over? Does it die? How might it cope with such damage?        

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49. Identify (and draw) some species of the basic morphologies of corals, including branching, massive, and platy forms. How would you interpret each shape as a strategy for feeding, sunlight, spatial competition, and resistance to storm damage.           

50. Because coral's race to live at the sea's surface, corals have proven an important piece of evidence for following changing sea level in Earth history. How fast can a coral grow? How long can a coral reef live? What have they said about current and past sea level and climate changes?        

Inhabitants of coral reefs The marine communities in this exhibit are those that form on the carbonate platforms of the 

world. Reefs, in some form, have been present on the Earth during most of Earth history. (Stromatolites are common Precambrian reefs built from algae!) A reef is a marine “framework” community that stands up from the ocean floor. Reefs are constructed by the interlocking growth of closely‐packed organisms that secrete calcium carbonate.  

All Phanerozoic reefs are constructed in much the same way, with each organism in the reef community performing a particular task (Precambrian reefs lacked animals, so the ecology may have been different). The five guilds of reef inhabitants are listed below. Each guild performs a particular task in building and maintaining a reef structure.  You will see during our second field trip that the general feeding strategies have remained the same since the Cambrian, but the types of organisms filling each guild have changed through time. 

1.  Constructors (builders) – these are the organisms that build the actual framework structure of the reef. In a modern reef, this role is played by scleractinian corals. The organisms that fill this role have hard skeletons, and are sessile.  In the past, they have been built by extinct coral groups, sponges, algae, and even brachiopods and oysters. 

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2.  Bafflers – the chief role of bafflers is to block or slow the flow of water over the reef and cause the deposition and stabilization of loose grains. These animals usually wave back and forth in the current on stalks attached to the constructors. They feed by filtering particles out of the moving water. In a modern reef, the main bafflers are the sea fans, which are a type of soft coral. Members of this guild are generally sessile benthonic filter feeders.  In the past, they have been bryozoans, crinoids, algae, and other organisms. 

3.  Binders – These organisms form the “glue” that holds the reef together. These organisms are encrusters that grow horizontally, covering surfaces and filling the holes in the reef. Modern members include sponges, calcifying algae, and bryozoans, and these have also played this role in the past. 

4.  Destroyers – These are animals that bore into, bite off, or otherwise destroy the structure of the reef. Today, these include solitary mobile animals such as parrotfish, sea urchins, and starfish, and also some kinds of sponges that bore into the reef. In the end, these organisms produce fine carbonate mud, which is transported off the reef, or falls into crevices in the reef.  The fossil record of such destroyers is somewhat unclear because of a lack of preservation. 

5.  Dwellers – These are animals that live on or in the reef simply because they prefer a hard substrate or protected cavity to hide. Many of these dwellers are nocturnal, coming out to feed at night when predators are less able to see them.  This group is a diverse group of sessile or mobile organisms, including sea anemones, clams and snails, crustaceans, fish, sharks, crinoids, starfish, octopuses, and brachiopods.  Similar animal groups took advantage of reefs like this throughout the Phanerozoic. 

 51. Fill out the following chart, describing some species you observe that do each reef role. 

Reef guild  Representatives 

Constructors (builders)   

Bafflers   

Binders   

Destroyers   

Dwellers   

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52. Pick a particular species and describe (and draw) in detail how it lives.  For example, what does it eat? What eats it? How does it reproduce? What size is it? Where it lives on the reef? When during the day is it most active? What special adaptations does it have?                                        

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Life on the soft ocean floor away from reefs 

The organisms that live on the soft ocean floor (mud, silt, sand) away from reefs are very similar to those that live on reefs, but these environments lack the stabilized substrate provided by reef constructors. Therefore, the community is better represented by the baffler and dweller guilds, but also with many organisms that burrow into the soft sediment.  Communities of shallow‐water, marine organisms that live on soft substrates are better represented in the fossil record than any other habitat. Shallow oceans flooded the continents through much of geologic history, and these environments are sites of relatively continuous deposition of sediments, and preserve a huge number of fossils. Today we will examine two examples of such habitats: the soft‐substrate habitat and the sea grass community.  Mangroves are another important habitat, but the record of them is very poor in the fossil record. 

 53. Observe representatives of these non‐reef communities and (1) name the various organisms found 

in each, (2) describe some of their ecological strategies, and (3) compare your observations to those from the coral reef communities.  

                          

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ADDITIONAL NOTES   

   

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ADDITIONAL NOTES   

   

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ADDITIONAL NOTES    

   

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ADDITIONAL NOTES