Essential Question

1. Essential Question • WHAT IS THE GEOLOGIC TIME SCALE?

2. Standard • Standard 8.E.6 The student will demonstrate an understanding of Earth’s geologic history and its diversity of life over time.

3. Performance Indicator
 8.E.6A.1: Develop and use models to organize Earth’s history (including era, period, and epoch) according to the geologic time scale using evidence from rock layers. 
 The Geological Time Scale

4. What is the Earth’s time scale? • The geologic time scale is a record of the major events and diversity of life forms present in Earth’s history. The geologic time scale began when Earth was formed and goes on until the present. It divides Earth’s long history into units of time. • Scientists developed the time scale by studying rock layers and fossils world wide.

5. What about the Geologic Time Scale? • Precambrian is the name given to the earliest span of time in Earth history. 


6. Reading and About the geologic time scale divisions • The geologic history of the Earth is broken up into hierarchical chunks of time. From largest to smallest, this hierarchy includes EONS, ERAS, PERIODS, AND EPOCHS. All of these are displayed in the portion of the geologic time scale shown below.

7. Eons Eras Periods Epochs BIG E = E + P = EP The geologic time scale divides Earth’s long history into units of time: There are 4 major subdivisions of Geologic Time Eons which subdivides into eras Eras which subdivides into periods Periods which subdivides into epochs

8. These subdivisions are based on large scale events in Earth’s history that are identified in the fossil record and rock layers.

9. The Phanerozoic Eon is subdivided into three major divisions: the PALEOZOIC, MESOZOIC, AND CENOZOICEras. The "-zoic" suffix comes from the root "zoo," which means animal. Cen-" means __RECENT_, "Meso-" means _MIDDLE__, and "Paleo-" means ___ANCIENT_.

10. What is the present day or modern day Eon, Era, Period, and EPOCH we live in? • EON: PHANEROZOIC • ERA: CENOZOIC • PERIOD: QUARTNERY • EPOCH: HOLOCENE

11. Cambrian being the first period is important. • With a more complete fossil record available, the periods of the Cenozoic era are subdivided further into epochs. • Geologic time has not ended.

12. At the end of each era a major mass extinction occurred, many kinds of organisms died out, although there were other extinctions going on during each period of geologic time. The layers of rock on Earth serve as evidence when identifying the geologic time scale. Using the fossil record, paleontologists (scientist who studies fossils)have created a picture of the different types of common organisms in each geologic period.

13. Check Point • Name the divisions in order from the largest to the smallest? • Name the divisions in order from the smallest to the largest? • Name the 3 Eras. • What is the present day or modern day Eon, Era, Period, and EPOCH we live in? • Triassic is a _________ • Precambrian has ____ Eons. • Name the 1st period and which Era do it belong to? • _______________is the only Era that contains epochs. • All Eras end with the suffix _____________. • All epochs end with the suffix _________________. • Has the Geologic time ended? How do you know?

14. Different types of Geologic Time Scale

18. Major information found on the geologic time scale includes: • During the first billion years of Earth’s history, the land was covered with volcanoes.Over the next 3 billion years, simple life-forms began to live in oceans.

19. TAKING A LOOK AT EACH DIVISION

20. The Precambrian Time!

21. The Precambrian Record

22. EARTH DURING PRECAMBRIAN TIME

23. TIMEFRAME • 4.6 billion to 544 million years ago

24. IMPORTANT FACTS - Earliest part of Earth’s history - covered approximately 88% of Earth’s history which makes it the longest part of Earth’s history. • Earth formed • Life arose • First tectonic plates arose and began to move • Atmosphere became enriched in oxygen • Is known as aSupereonbecause it is divided into 3 eons (Proterozoic, Achaean, and Hadean)

25. Precambrian Time

26. Animals (Biological) Features • Most organisms had soft bodies which looked like modern jellyfish and worms • Many Precambrian fossils are Trace fossils.

27. 630 MYA Precambrian Time • Multicellular organisms evolve with soft bodies • Species include: jelly fish; coral stalks; segmented worms; algae

28. Animals (Biological) FeaturesLand (Geological) Features • Primarily covered by the ocean • Had a lot of volcanicactivity

29. MASS EXTINCTION • MASS EXTINCTION IS THE EVENT THAT ENDED PRECAMBRIAN TIME. • * glaciation event • Precambrian time were marked by a prolonged global ice age. This may have led to widespread extinctions.

30. Check Point • Precambrian Time was mostly covered by what? • Precambrian Time was the ______ part of the Earth’s history • What types of animals lived during Precambrian time? • Precambrian Time is known as a ________ because it contains 3 eons. • What caused the mass extinction of Precambrian Time?

32. PALEOZOIC ERA • KNOWN AS THE AGE OF FISH OR TRILOBITES

34. Paleozoic Era Timeframe • 544 million to 248 million years ago

35. Paleozoic Era Life starts in the seas and moves onto land Six periods: Cambrian Ordovician Silurian Devonian Carboniferous-2 periods included Permian

36. Important Facts • Pangeawas forming during this era as far as coming together • Cambrian being the first period is important. • The Cambrian Explosion was a time where there was a relatively rapid appearance of most major animal phyla as evidenced by the fossil record.

37. Cambrian “explosion” For reasons unclear, 13 million years after the start of the Cambrian (so 530 my), there was a tremendous diversification of marine life forms, some of which have never been reproduced. Cambrian Explosion – Most major animal phyla are found in the fossil record (mostly aquatic invertebrates with exoskeletons).

38. Animals (Biological) Features • Began with the early invertebrates, such as trilobites and brachiopods WHAT FIRST APPEARED: • Trilobites • fish • arachnids and insects • first amphibians • near the era’s end the reptiles became dominant. WHAT BECAME DOMINANT: • Trilobites • Fish

39. Lived in Earth’s ancient seas Extinct before the dinosaurs came into existence Cambrian Period is know as the “Age of the Trilobites” (put in on table) Trilobites

40. Brachiopods • Marine animals that resemble clams.

41. Early Fish Early fish did not have jaws. Some species of sharks were in existence at this time.

42. Frilled Shark that was found in Japan in January 2007. This shark was considered a “living fossil”

43. Land (Geological) Features • During most of the Era, warm shallow seas covered much of the planet. WHAT FIRST APPEARED: • Simple mosses • Ferns • Cone-bearing plants • Seed plants

44. Early Land Plants Mosses Cone bearing plants Ferns

45. HOW EARTH LOOKED DURING THE PALEOZOIC ERA

47. Mass Extinction • The mass extinction that ended the era caused most marine invertebrates as well as amphibians to disappear. • About 95 percent of marine species and 70 percent of land animals were wiped out after the Permian mass extinction. • It is suspected that periods of rapid global warming and cooling that happened so quickly most organisms were not able to adjust.

48. WHAT CATASTROPHIC EVENT CAUSED THE MASS EXTINCTION??? 3 THINGS • 1. volcanic activity • 2. Climate Changes • 3. lowering of sea levels as Pangaea was forming (convergent boundaries)

49. Mesozoic Era(Age of the Dinosaurs or Reptiles) Three Periods Triassic Jurassic Cretaceous