Exploring Earth's Geologic History: Timeline of Events

1. Geologic Eras • Today’s Goal • I can list the four major divisions of geologic history in order and describe them Homework Finish Precambrian questions at the end of the notes

2. Day 1 • Complete the Geologic Time Jigsaw Activity • 15 minutes max

3. Geologic Time JigsawANSWER KEY

4. Precambrian Time (pg 142-143) 1. What length of time does the Precambrian cover? 4.6 BYA to 543 MYA 2. List TWO ways the earth was different during the Precambrian time compared to today. different gases in atmo; volcanic eruptions; meteor impacts; violent storms; intense radiation 3. How do scientists think life got started? simple chemicals from oceans and atmosphere 4. What gas was missing in the early atmosphere that the first organisms did not need? oxygen 5. Why was the evolution of cyanobacteria important? carried out photosynthesis; produced oxygen; used sun’s energy to make food 6. Why was the formation of the ozone layer important? protects life against harmful UV rays 7. Eukaryotes evolve about one billion years ago. How were they different from prokaryotes? larger size; has a nucleus; lead to multicellular life

5. Paleozoic Era (pg 144) 8. What length of time does the Paleozoic Era cover? 543-248 MYA 9. What are rocks of this era rich with? fossils 10. What does “Paleozoic” mean? Ancient life 11. What were the first vertebrate animals to evolve? fish  12. Which major plant group did NOT evolve during this era? Flowering plants 13. What were the first animals on land? Insects were first and then eventually amphibians  14. When did reptiles evolve during this era? Late Paleozoic Era 15. What happened at the end of the era? Mass Extinction

6. Mesozoic Era (pg 145) 16. What length of time does the Mesozoic Era cover? 248 to 65 MYA 17. What does “Mesozoic” mean? Middle life 18. What was the Mesozoic Era commonly known as? Age of the reptiles 19. How long did dinosaurs dominate the Earth? 150 MYs 20. What group of organisms around today likely evolved from a group of dinosaurs? birds 21. When did flowing plants evolve during the Mesozoic Era? Late Mesozoic Era 22. Describe the hypothesis that explains how the dinosaurs went extinct. meteor hits earth, dust from the impact circles earth blocking out sun for long period of time 23. Who survived the mass extinction at the end of the Mesozoic Era? Mammals and birds

7. Cenozoic Era (pg 146-147) 24. What length of time does the Cenozoic Era cover? 65 MYA to Present 25. What does “Cenozoic” mean? Recent Life 26. Provide THREE examples of groups of organisms that appeared in the Cenozoic Era. mammals; birds; insects; flowering plants 27. What is the Cenozoic Era commonly known as?  Age of Mammals 28. How did mammals change during the Cenozoic Era? they became larger 29. List THREE types of mammals that existed during the Cenozoic Era but no longer exist. Mastodons; Saber-toothed cats; Giant ground sloths; Small horses 30. How did the climate change during the Cenozoic Era? Ice Age periods

8. Earth’s History in a Year Purpose: To gain a perspective on the vast amount of time required for life on Earth to evolve. The scale of geologic time is vast, currently estimated at nearly 4.6 billion years. During that time, life evolved into the familiar forms we see today. These materials are provided to assist in understanding time relationships and how life on Earth changed through time. The dates shown were compiled from several available sources. TABLE 1 shows some important events in Earth history, presented in the order in which they occurred. The data are also shown on the scale of a calendar year. When geologic time is compressed to the scale of a calendar year…. 1 day =12,600,000 years 1 second = about 146 years At this scale, World War II began about 0.4 second before midnight on December 31.

9. Procedures: • 1. On your worksheet “calendar” label all of the events listed on TABLE 1 on your calendar at the correct date. • Using FOUR different colored pencils, shade the time span of each of the four ERAs listed on TABLE 2 (Cenozoic, Mesozoic, Paleozoic, Precambrian) on your calendar. Shade each ERA a different color. Label each of the Eras on your calendar by using a key located at the top of the calendar.

10. Precambrian Era • Today’s Goal • I can explain how life starts • I can describe earth’s early atmosphere • I can understand the importance of cyanobacteria Homework Answer Paleozoic Questions

11. The Geologic Time Scale The standard method used to divide the Earth’s long natural history into manageable parts Precambrian Time accounts for 85% of Earth’s History!!

12. Oldest rock found in Western Australia The center of Earth was melted by great pressure and intense heat. An atmosphere formed as Earth cooled. The Earth Forms primitive atmosphere forms from volcanic eruptions Did NOT contain oxygen gas Oceans form from water vapor released in eruptions & maybe comets 4.1BYA The surface of Earth cooled forming the crust 6 BYA The Solar system formed from swirling gases and dust 4.5BYA Rocks in the solar system condensed to form Earth

13. Comparison of Atmospheres

14. Where did Life Start? • Hydrothermal Ocean Vents • nutrient rich, possibly with complex molecules which may have joined together to form structures such as cells • Ocean covered in Ice • extra protection from UV radiation • Meteorites or Comets • rich with building blocks of life

15. What does it mean to be living? • Be able to reproduce • Uses energy • Composed of one or more cells • Contains genetic information

16. 3.0 - 3.5 BYA Oldest fossils of bacteria (prokaryotes). • Lack a nucleus • Do not need oxygen to survive

17. 3.0 BYA Cyanobacteria (blue-green algae) evolve • creates energy from photosynthesis • gives off oxygen gas (beginning to form the atmosphere of today) • Form large stromatolites (below)

18. 1.5 BYA • Eukaryotes • contain a nucleus • Evolved from prokaryotes

19. 630 MYA • Multicellular organisms evolve with soft bodies Species include: jelly fish; coral stalks; segmented worms; algae

20. Order of Events

21. Precambrian Time • Earth’s Crust cools • Sun forms • Left over material from our sun collides to form the planets • Earth was entirely molten • Atmosphere & oceans form • Eukaryotes (cells with a nucleus) • Oldest known rock • Cyanobacteria (photosynthetic) • Bacteria or prokaryotes (cells without a nucleus) • Multicellular life (examples: sponges)

22. Precambrian Time (Answers) • Sun forms • Left over material from our sun collides to form the planets • Earth was entirely molten • Earth’s Crust cools • Atmosphere & oceans form • Oldest known rock • Bacteria or prokaryotes (cells without a nucleus) • Cyanobacteria (photosynthetic) • Eukaryotes (cells with a nucleus) • Multicellular life (examples: sponges)

23. Day 2 Using a scrap piece of paper, put your name on it and number 1-5 and answer the following challenge questions • What are the four major divisions of geologic history? • What were the first living organisms called? (HINT they did not need oxygen to survive!) • What does the word Paleozoic mean? • Mesozoic era is commonly called the _________________. • What period are we currently living in today?

24. Paleozoic Era • Today’s Goal • I can list the 6 periods in the Paleozoic Era and events that happen in each Homework NONE

25. Precambrian Recap!

26. Paleozoic Era Means “Ancient Life” Life starts in the seas and moves onto land Six periods: Cambrian Ordovician Silurian Devonian Carboniferous Permian

27. Cambrian Period(570-500 MYA) • Cambrian Explosion – Most major animal phyla are found in the fossil record • mostly aquatic invertebrates with exoskeletons • Burgess Shale – major fossil site located in Canadian Rockies

28. Ordovician Period(500-435 MYA) • 1st vertebrates - jawlessfish (filter feeders) • The vertebrate protects the spinal cord, which carries signals from the brain throughout the body. The lamprey of today is a parasite The hagfish is a scavenger

29. Silurian Period(435-395 MYA) • 1stjawed fish • later evolved into sharks- made of cartilage • Ozone (O3) layer formed which blocks harmful UV radiation • life could evolve on land • 1st land plants • mosses & ferns

30. Devonian Period(395-345 MYA) • “Age of the Fish” • 1stbony fish • scales and swim bladder for buoyancy • 1st insects • Arthropods-spiders & scorpions • 1st vertebrates on land • Amphibians • Evolved from the lobed-fin fish which include some species of lungfish

31. View of Earth—Devonian Period (410 MA)

32. Carboniferous Period(345-280 MYA) • North America is at the equator • Tropical swamps form coal deposits • Climate is very warm • Amphibians & insects dominate and become large • Dragon flies (1 m wing span) • Cockroaches (10 cm long) • 1st reptiles

33. View of Earth—Carboniferous Period (330 MA)

34. Permian Period(280-225 MYA) • Reptiles dominate • Pangaea begins to form • Ancestral North America collided with Africa to produce Appalachian Mountains • dry climate • ice age in the southern hemisphere • Mass Extinction • More than 90% of all marine invertebrates go extinct • 70% of all land species go extinct

35. Order of Events

36. Paleozoic Era • Jawless fish (ex. Lamprey) • Ocean invertebrates made of soft tissue (ex. Jellyfish) • Bony fish (ex. Salmon & Flounder) • Ocean invertebrates made of an exoskelton (ex. Trilobite) • Jawed fish (ex. Shark) • Invertebrate on land (ex. Insects & Scorpions) • Greatest Mass Extinction • Land Plants • Reptiles • Amphibians • Ozone layer

37. Paleozoic Era (Answers) Ocean invertebrates made of soft tissue (ex. Jellyfish) Ocean invertebrates made of an exoskelton (ex. Trilobite) Jawless fish (ex. Lamprey) Jawed fish (ex. Shark) Bony fish (ex. Salmon & Flounder) Ozone layer Land Plants Invertebrate on land (ex. Insects & Scorpions) Amphibians Reptiles Greatest Mass Extinction

38. Mesozoic Era • Today’s Goal • I can list the 3 periods in the Mesozoic Era and events that happen in each Homework Answer Homework Questions

39. Homework Questions • What are the 6 periods of the Paleozoic Era in order? • What period did jawless fish begin to appear? • What period did the ozone layer form? • What period is considered to be “the age of the fish”? • What period did the first reptiles show up in?

40. Mesozoic Era(Age of the Reptiles) 248 million years ago to 65 million years ago Pangaea separates Three Periods Triassic Jurassic Cretaceous

41. View of Earth—Permian Period (260 MA)

42. Mesozoic Era(Age of the Reptiles) 248 million years ago to 65 million years ago Three Periods Triassic Jurassic Cretaceous

43. Triassic Period(225-180 MYA) Pangaea (supercontinent) formed

44. Triassic Period(225-180 MYA) First Dinosaurs (small in size) Pisanosaurus Length:3 feet Height:1 foot Weight:15 pounds Eoraptor: Length:3 feetHeight: 1 footWeight:20 pounds Lesothsaurus: Length:3 feet Height:1 foot Weight:15 pounds

45. Triassic Period(225-180 MYA) Conifers and cycad forests dominate (Gymnosperms)

46. Triassic Period(225-180 MYA) First turtles and lizards

47. Jurassic Period(180-135 MYA) Pangaea starts to separate

48. Jurassic Period(180-135 MYA) Dinosaurs diversify and dominate

49. Jurassic Period(180-135 MYA) Reptiles in the sea • Most with similar shapes as a dolphins or sharks • Ate fish and other marine animals • Some were VERY large • All could swim VERY fast

50. Jurassic Period(180-135 MYA) 1st mammals (small rodents).