recorded human history, rise and fall of civilizations, global warming, habitat destruction, pollution mass extinction
0.01
Pleistocene
Homo sapiens, ice ages
1.6
Tertiary
Pliocene
global cooling, savannahs, grazing mammals
5.3
Miocene
global warming, grasslands, Chalicotherium
24
Oligocene
37
Eocene
modern mammals flourish, ungulates
58
Paleocene
66
Mesozoic
Cretaceous
last of age of dinosaurs, modern mammals appear, flowering plants, insects
144
Jurassic
huge plant-eating dinosaurs, carnivorous dinosaurs, first birds, breakup of Pangea
208
Triassic
lycophytes, glossopterids, and dicynodonts, and the dinosaurs
245
Paleozoic
Permian
Permian ends with largest mass extinction in history of Earth, most marine inverterbrates extinct
286
Pennsylvanian
vast coal swamps, evolution of amniote egg allowing exploitation of land
320
Missipian
shallow seas cover most of Earth
360
Devonian
vascular plants, the first tetrapods, wingless insects, arachnids, brachiopods, corals, and ammonite were also common, many new kinds of fish appeared
408
Silurian
Coral reefs, rapid spread of jawless fish, first freshwater fish, first fish with jaws, first good evidence of life on land, including relatives of spiders and centipedes
438
Ordovician
most dry land collected into Gondwana, many marine invertebrates, including graptolites, trilobites, brachiopods, and the conodonts (early vertebrates), red and green algae, primitive fish, cephalopods, corals, crinoids, and gastropods, possibly first land plants
505
Cambrian
most major groups of animals first appear, Cambrian explosion
570
Proterozoic
stable continents first appear, first abundant fossils of living organisms, mostly bacteria and archeobacteria, first eukaryotes, first evidence of oxygen build-up
2500
Archean
atmosphere of methane, ammonia, rocks and continental plates began to form, oldest fossils consist of bacteria microfossils stromatolites, colonies of photosynthetic bacteria
3800
Hadean
pre-geologic time, Earth in formation
4500
Bibliography
Foster, Robert. Geology. 3rd ed. Columbus, OH: Charles E. Merrill, 1976.
Stanley, Stephen. Earth and Life Through Time. New York: W. H. Freeman, 1989.
Toulmin, Stephen and June Goodfield. The Discovery of Time. New York: Harper & Row, 1965.
