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cambrian period 542 million years ago
22 trilobites appear 23 shelled brachiopods appear -
Ordovician period 488 million years ago
1 There is very little plant life during this period 30 colonies of tiny invertebrates flourished and verb rates appear fish did not have jaws or teeth and their bodies were covered with bony plates. -
silurian period 444 million years ago
24 eurypyerids (sea scorpions) sea stars and coral become more common 33 vascular land plants and animal such as scorpions begin to evolve on land. -
Devonian peroid 416 million years ago
31 huge plants begin to develop early amphibians form 37 age of fishes fix that can breath out of water and spend time on land form -
precambrian time 4.6 billion years ago
10 the presence of stromatolites indicates that shallow seas covered much of the earth during intervals. 11 nearly half of the valuable mineral deposits in the world occur. -
M zapata p7
