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Cambrian Period 570 to 500 MYA
This is the period where a lot of animals appeared in fosils. The climate was cold to begin with which made the sea a good place for animals. All of a sudden alot of life forms were created. Alot of them lived in water. They had no backbones in the shallow seas. Oxygen levels were rising enought that they could support animals. Animals that lived in this period were Arthropod's they have tough outter skin. They also were one of the first animals to have eyesight. There were also Mollusks, Worms, -
Ordovician 500-435MYA
The animals they had at that time were graptolites, trilobites brachiopods and conodonts. The climate changed. The weater became warm and there was more moisture in the air. Many glaciers formed which made sea levels drop. 60% of the invertebrates went extint. Most of the life was still found under water. There were plants now for the first time but they lived in the water because they didnt have veins for moving water. The water had to flow through the plant in order for the plantto get water -
Silurian 435-395 MYA
The weather was becoming warmer. That made the glaciers melt therefore making the sea leves rise. Fish were starting to get lower jaws. The plants had to learn how to live on land or else thaey would die. -
Devonian 395-345
This was called the age of fish.Two major plants were zosterophyllophytes and trimerophytes. Plants developed vascular tissues. That helped them carry food and water. The first trees were created in this period. Land living vertebrates came on to earth and wingless insects. This is when alot of fish changed and there was a large variety. Alot of them developed jaws, gills, and paired fins. -
Carboniferous 345-280 MYA
There was a ton of coal made at this time. Alot of trees grew at the time. The forests got rid of carbon dioxide and left the atmospere full of oxygen. Triolbites were getting less common and were becoming extint. Armored fish ruled the seas but then they became extint and then modern day fishes took over. There was a big climate change and alot of animals died but they didnt go extint. -
Permian 280-225 MYA
Alot of the land was together. The land was pretty dry. In this time there was the largest mass extinction ever. 90% of marine animals died. 70% of land animals died. Reptiles got thicker skin. Fishes had bones and fins that were thick and heavy scaled. Plants got use to the dry conditions. -
Triassic 225-195 MYA
Because so many animals died new ones were created. This period didnt have alot of green plants and trees, but there was an explosion of cycads, ferns and gingko trees. There wasnt enough vegatation for dinosaurs to live. So there were not that many dinosaurs anymore. -
Jurassic 195-136 MYA
Dinosaurs dominated the land. The plants got greener and more lushious. The climate was hot and humid. There was steady rain fall. The weather was perfect for plants. Some plants were ferns, conifers, cycads club mosses and horsetails. The water animals grew alot as well as the dinosaurs. Some water animals were Pliosaurs, Liopleurodon< Crytoclidus, Plesiosaurus, Prehistoric fish and Prehistoric sharks. -
Cretaceous 136-65 MYA
This is the end of the "Age of Dinosaurs". Alarge crater killed them.Also valcanos were active and that killed the dinosaurs as well. The first flower plants developed. This is when grass started showing up as well. Also modern day birds. The earth was still warm and the sea levels rose again. The continents were starting to form the shapes. There was a new breed of bony. -
Tertiary 65-1.8 MYA
The large species died which allowed to the rise of mammals. North and South America separated which opedned up the oceans. Contnents were finnaly in place. The climate was cooling. There was 5 opochs. Paleocene, Eocene, Oligocene, Miocene and Pliocene. There was bears, hyenas, dogs,cats, seals, walruses, whales, dolphins, hoofed mammals, horses, hippos, rabbits, monkeys, apes and humans. -
Quaternary 1.8MYA-Present
Some animals got massive, grew big fur coats and then disappeared, Continents are finnaly in place.Sea levels rose. This group was split into 2 sections, Pleistocene and Holocene. Mammoths, Cattle, Deer, Homo habilis,Homo erectus and Homo sapiens.
