Field Trip 11: Los Angeles County Natural History Museum

Introduction

The Natural History Museum of Los Angeles County (NHM) is the largest natural and historical museum in the western United States, with a collection that includes nearly 35 million specimens and artifacts, spanning 4.5 billion years of history (www.lacounty.gov). The museum opened in 1913 in what is now called Exposition Park and has since gone through at least 5 expansions and renovations.

This chapter will focus on the earth science related exhibits in the museum: the Gem and Mineral Hall, the Dinosaur Hall, and The Age of Mammals exhibit. The intent of the questions is that they will serve as an inquiry-based means of motivating students to undertake an interesting and educational self-guided tour of the museum. You could also consider using this activity as a “make up” field trip for students that were unable to attend other field trips required by your course.

Students should plan for a half a day or longer at the museum. I encourage my students to “make a day of it” and go with classmates, significant others, brothers, sisters, parents, or friends and embrace the experience. The magnificent building housing the museum is officially listed as a National Registry of Historic Places, and the outdoor grounds and Rose Garden are beautiful as well. In addition to the three exhibits students need to visit to complete this assignment, there are many other interesting permanent and “special” exhibits within the NHM that add to the experience. The NHM museum shares the Exhibition Park campus with the California Science Center (free entrance), the Los Angeles City Rose Garden (free entrance), and the California African American Museum, all of which are just few minutes walk from the NHM.

Admission costs are reduced for students and for groups. If you wish to arrange a group visit call the museum at (213) 763-3218. There are a variety of resources offered through the NHM website that can help you and your students prepare for an educational visit to NHM, as well as academic fee waiver applications for qualifying individuals or institutions: resources for teachers Links to an external site..

Parking in the NHM lot is currently $13 and can be found immediately southwest of Bill Robertson Lane and Exhibition Boulevard. Encourage students to carpool or take the metro to the Expo Park stop, which is immediately north of the NHM.

Note that Exhibition Park also contains the LA Memorial Coliseum and Banc of California stadium, which can make for horrific traffic if either are hosting an event. Plan accordingly.

Learning Objectives

Through participation in this field trip students should be able to:

  1. Name California’s geologic provinces
  2. Identify the geologic province most associate with California’s gold and silver deposits
  3. Collect data to compile a “research report” about a mineral
  4. Describe the role the San Andreas Fault has played in forming the mountains of southern California
  5. Describe how the amount of offset in sedimentary layers relates to the magnitude of an earthquake
  6. Summarize the potential impacts of a major earthquake on the San Andreas Fault in southern California.
  7. Identify the luster and crystal shape/habit in mineral specimens
  8. List the physical traits that are definitive of dinosaurs
  9. Relate geologic Eras and Periods to geologic events during the time of the dinosaurs
  10. Relate plate tectonics to the distribution of dinosaurs
  11. Describe how environmental factors can drive the evolution of mammals

Key Vocabulary

Chemical formula – a means of representing the ratio of atoms of elements that make up a compound using symbols and numbers, e.g. H2O

Crystal habit – the general shape of a crystal; can be variable for a given type of crystal depending on the environment in which the individual crystal grows  

Dinosaur – any reptile of the subclass Archosauria distinguished from other reptiles especially by features of the pelvic bones (Bates and Jackson, 1987)

Evolution – how a group of related organisms adapt to environmental conditions over time

Fault – a fracture in Earth’s crust along which movement has occurred

Fossil – the preserved remains, impression, or trace of a past living organism

Luster – the quality of light reflected by a mineral

Mammal – warm-blooded vertebrates that have fur or hair and secrete milk to young produced through live birth

Pre Field Questions

  1. Using your textbook or other resources provided by your instructor, answer the following questions:
  2. What physical properties are used to identify minerals?
  3. What controls the color of different minerals?
  4. What controls the crystal shape/habit of a mineral?
  5. What is meant by the “luster” of a mineral? What are the two principal types of luster?
  6. List the different types of non-metallic luster, from most lustrous to least lustrous.

Gem and Mineral Hall

Entrance

  1. Describe the color of amethyst, malachite, pyrite, microcline, and rhodochorsite.

Map of the gem and mineral hall.

Simplified map of Gem and Mineral Hall.  Not to scale. 

A. Walls to the right of entrance

  1. List California’s 7 geologic provinces.
  2. List your favorite mineral from each geologic province (keep same order as above).
  3. In which geologic province are gold and silver most important?
  4. List 5 minerals found in San Diego County.

E. Elabaite Tourmaline

  1. How does this specimen differ from those you’ve observed in class?

Video Questions

  1. How were the mountains of southern California made?
  2. How are the magnitude of an earthquake and the amount of offset in sedimentary layers related?
  3. Which segment of the San Andreas fault hasn’t had an earthquake in historic times?
  4. What sequence of events is needed to produce a magnitude 8 earthquake in southern California?
  5. Why would a major earthquake on the San Andreas fault jeopardize the water supply for Los Angeles?
  6. Describe the role the San Andreas fault has played in causing Transverse Ranges to have an east-west orientation.

M. Meteorites

  1. What is the difference between meteoroids, meteors, and meteorites?
  2. Which type is most rare?
  3. What minerals to meteorites contain?
  4. What is the origin of meteors?

B. Forming minerals

  1. What are the three environments in which minerals form? Give an example of a mineral from each.

C. Systemic Mineralogy Wall

  1. Which common minerals are included in the Tectosilicates?
  2. Find at least three varieties from the feldspar mineral group. Chemically, how do they differ from one another?
  3. List the different colors are the quartz specimens?
  4. What mineral class does muscovite belong to?
  5. What mineral class does staurolite belong to?
    a. Sketch a staurolite crystal.
  6. What is the most obvious difference between azurite and malachite?
  7. How many different colors do the barite specimens show?
  8. What mineral class does calcite belong to?
  9. How would you describe the shape of the galena crystals?
  10. How would you describe the shape of the stibnite crystals?
  11. How would you describe the shape of native gold and silver?
  12. What is one mineral that contains Mercury? (Hg)
  13. What are some of the minerals that contain Lead? (Pb)
  14. What are some of the minerals that contain Zinc? (Zn)
  15. What are some of the minerals that contain Copper? (Cu)
  16. Take a little time to admire the minerals in the 12 freestanding cases in the middle of the room. Write down your favorite mineral specimen in each case.
  17. Name one mineral that shows an example of:
    a. metallic luster
    b. vitreous luster
    c. pearly luster
    d. waxy luster
    e. dull/earthy luster
    f. fibrous habit
    g. cubic shape/habit
    h. needle shape/habit
    i. tabular shape/habit
    j. prism shape/habit
    k. bladed shape/habit
    l. dodecadhedron shape/habit

Gem Vault

  1. Find the gemstones of fluorite, orthoclase, calcite, pink tourmaline, and blue topaz. List their color and carat weight.

35. Which state produces the greatest number and variety of gemstones? 

Dinosaur Hall

Refer to the museum map Links to an external site. if you’re not sure where to go.

  1. What makes a dinosaur a dinosaur?
  2. What is a defining feature of all dinosaurs?
    • What two anatomical features allow for this physical trait?
  3. What animal group do dinosaurs belong to?
  4. What span of time is covered by the Mesozoic Era?
  5. What descendants of the dinosaurs do you see most every day?
  6. What are the two main dinosaur groups?
    • Which group of dinosaurs would Tyrannosaurus Rex belong to?
    • Which dinosaur group was made up of mostly plant eaters? Give one example of dinosaurs from this group.
  7. What was the “headgear” of dinosaurs used for?
  8. What were the tail spikes and bony plates along the spine of a Stegosaurus used for?
  9. During which geologic Era did dinosaurs thrive?
  10. During which 3 geologic Periods did dinosaurs evolve?
  11. During which geologic Period did Pangaea begin to disassemble?
  12. In which geologic Period did dinosaurs originate?
  13. During which geologic Era did mammals diversify?
  14. Which geologic Period is defined by appearance of humans?
  15. What explains why fossils of some dinosaurs, like Majungasaurus, can be found as far apart as South America and Madagascar?  
  16. How is it possible that dinosaurs once lived near the South Pole?
  17. How do rocks tell us about past environments?
  18. Where was the Western Interior Seaway?
    • How did this seaway impact the geography of North America?
    • What geologic evidence do we have for the existence of this seaway?
  19. Why did dinosaurs evolve from walking on just two legs to walking on four?
  20. Were most dinosaurs carnivorous or vegetarians?
  21. During which geologic period did T-Rex live?
  22. Is the large T-Rex named “Thomas” fully grown?
  23. How common are T-Rex fossils?
  24. How long ago did the dinosaurs go extinct?
    • What caused the extinction?
    • Name four pieces of evidence scientists use to support this theory.
  25. What is the name of the largest dinosaur species on display?
  26. What are the same traits that survivors of the mass extinction shared?
  27. What features do the dinosaurs of today share with dinosaurs of the Mesozoic?
  28. Give one trait of dinosaurs during each of the three geologic Periods of the Mesozoic.

Upstairs 

29. In general, did dinosaurs grow faster or slower than other animals?
30. What might a dinosaur have sounded like?
31. What was dinosaur skin like? How do we know?

Atrium (start at “Early Cambrian Scene” then walk clockwise around the balcony)

32. Answer the following question for each animal below: How long ago did _______________ exist?

    • Ammonoids and trilobites
    • Archaeopteryx
    • Stegosaurus
    • Pteranodons
    • Giant rhinoceros
    • Wooly mammoth

Age of Mammals Exhibit (start on first floor)

Refer to the museum map Links to an external site. if you’re not sure where to go.

  1. Did dinosaurs and mammals exist on Earth at the same time?
  2. When did the “Age of Mammals” begin?
    • Why did it begin at that time?
  3. What are four physical traits that make a mammal, a mammal?
  4. Watch the video “Mammals Evolve” on the flat panel screen to the right of the American Mastodon. When did the dinosaurs die out?
  5. Do mammal species typically get larger or smaller over time?
    • Why?
    • Why would a species become larger through evolution?
    • Why would a species become smaller?
  6. What was the main reason large carnivores, like saber-tooth cats, went extinct?
    • When did this happen?
  7. What are 3 factors that could have led to the extinction of large herbivores, like the giant camel?
  8. Where were the fossil remains of the mastodon skeleton found?
  9. What were 2 things that allowed humans to migrate out of Africa?
  10. When did Homo sapiens first appear?

Upstairs

  1. What evidence do we have that the climate was cooler 50,000 years ago in Los Angeles?  
  2. What was the environment of the L.A. Basin like 15,000,000 years ago?
    • How do we know?
  3. What was the climate like in the Mojave Desert 10,000,000 years ago?
    • How do we know this?
  4. What was the environment of the L.A. Basin like 27,000 years ago?
  5. What is meant by “Older is Deeper” when referring to sedimentary rock?
  6. What do foraminifera tell us about past climates?
  7. During the past 65 million years, when has the climate warmed the fastest and why?  

To add to this field trip study of the history of mammals through museum exhibits, refer to the next chapter, The La Brea Tar Pits.

Follow up Questions

  1. What controls the color in minerals? Give some examples.
  2. What controls the cleavage of a mineral? Why do some minerals not have cleavage?
  3. What controls the crystal shape (crystal habit) of a mineral?
  4. Mineral Report. Choose a mineral and identify the following for that mineral:
    • Color(s)
    • Chemical formula
    • Mineral class; explain why the mineral belongs in that class
    • Crystal habit
    • Luster
    • Hardness
    • Cleavage
    • Typical occurrence in nature
    • Industrial uses/economic value
  5. Why did the dinosaurs go extinct? Site more than one cause using information from the museum as well as at least two additional resources.