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Earth and its solar system were forming.
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life first appeared
oldest fossils are 3.5 billion years old -
stable continents appeared
bacteria, archeans, and eukaryotics began to appear -
mjor groups of animals appeared in the fossil record
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area north of the tropics was almost ocean
known for its diverse marine invertebrates, including graphtolites, trilobites, brachiopods, and conodonts -
rapid spread of jawless fish
relatives of spiders and centipedes
evidence of vascular plants -
ferns, horsetails, and seed plants
three major continental masses (North America and Europe, Siberia, and South America, Antartica, India and Australia) -
more tropical humid climate than today
more modern looking fish appeared -
end of the Permian period has the largest mass extinction recorded in the history of the Earth.
plants shifted to gymnosperms -
breakup of Pangaea
low sea level and high elevated continents -
plant eating dinosaurs, fish, squid and ammonites were populous
plenty of land plants, and early mammals no bigger than rats -
extinction of the dinosaurs
diversification of modern insects -
oldest known fossils of most modern mammals appear
mammals such as horses, deer, camel, elephants, cats, and dogs existed -
pattern of biological change where we see different climates
Sierra Nevada and Cascade Mountain ranges formed. -
one of the largest land animals, the mammoth, was alive
saber-toothed cats, sloths, and other large mammals lived in North America
Beginning 11, 700 years ago, humans came into existence