1. Grade 7 Science

2.  3 very long Eons:  Hadean,  Archean and  Proterozoic;  Covers 87% of earth’s history;  Formation of earth, volcanic activity;  Atmosphere and oceans formed;

3.  A thick, stable crust was formed;  Oldest rock evidence = 4.3 billion years old;  Algae and bacteria were the first life forms;  Jellyfish and worms evolved towards the end of this time period.

4.  Latest 13% of earth’s history;  3 smaller periods called “Era’s”  Paleozoic: “Age of Fishes” or “Age of Ancient Life”  Mesozoic: “Age of Dinosaurs” or “Age of Medieval Life”  Cenozoic: “Age of Mammals” or “Age of Recent Life”

5.  “Age of Fishes” or “Age of Ancient Life”;  7 “Periods”, first is called the Cambrian, hence, all previous time is called the “Pre-Cambrian”  This first Era covers over half of the Phanerozoic Eon.

6.  “Pangea” forms: Motion of the earths crustal plates brought much of the total land together and fused into a super-continent.  Era begins when animals first developed skeletons (exo-)

7.  Ends with major catastrophe that wiped more species off the face of the earth than at any other time in history (Permian extinction: 95% of all species)  Scorpions and centipedes were the first animal to live on land.  Insects, fern-like plants and conifers (trees that have cones) developed.

8.  “Age of Dinosaurs” or “Age of Medieval Life”;  3 “Periods”:  Triassic  Jurassic  Cretaceous

9. Triassic Period:  Pangea breaks apart;  Dinosaurs and mammals first appeared.

10. Jurassic Period:  Rocky Mountains form;  First birds appear.

11. Cretaceous Period  Flowering plants appeared;  Period ends in a mass extinction (by an asteroid???)

12.  “Age of Mammals” or “Age of Recent Life”;  2 “Periods”:  Tertiary and  Quaternary.

13. Tertiary Period:  Mountain building:  Andes, Alps, Himalayan and Western North America

14. Tertiary Period:  Modern mammals, new birds, first horses, saber- tooth tiger, whales, first elephants and mastodons.

15. Tertiary Period:  First Humans  “Ardi” (4.4 mya)  (Ardipithecus ramidus) ??? Ardipithecus kadabba 5.6 mya

16. Quaternary Period:  Ice Ages to the present;  Extinction of large mammals such as wooly mammoths;  Modern humans appear and dominate.