START of the PALEOZOIC ERA
• Continents separate
• North American continent at the equator with the Arctic region facing eastward
PALEOZOIC PERIODS
Cambrian
Ordovician
Silurian
Devonian
Mississippian
Pennsylvanian
Permian
• Trilobites, 1st vertebrates
• Graptolites, 1st corals
• Eurypterids, 1st land animals
• Age of fishes, 1st forests
• Crinoids & Foraminifera
• Age of Cockroaches, 1st reptiles
• Pangaea forms, 1st mammals
CAMBRIAN PERIOD
• No land plants or animals
• Most of North America covered with warm oceans
• Burgess Shale forms in the Rocky Mountain region with soft bodied animals
• Common fossils– Trilobites (like crabs) - index
– Brachiopods (like clams)
– Ostracoderms (primitive fish)
ORDOVICIAN PERIOD
• All life exists in the oceans
• Small plate from northwest Africa collides with eastern North America to form the Green & Taconic mountains
• Common fossils
– Graptolites (colonial floating animals) - index
– Brachiopods, bryozoans, pelecypods, corals,
echinoderms, gastropods, cephalopods
SILURIAN PERIOD
• 1st land animals– Ancestors of spiders, millipedes, scorpions
• Land plants– Club mosses
• Eastern North America– Dry climate evaporates the shallow seas leaving large
salt & gypsum deposits
• Common fossils– Eurypterids (sea scorpions) – index
– Coral forming coral reefs, others like Ordovician life
DEVONIAN PERIOD
• Age of Fishes– Lungfish lived briefly on land
• 1st forests– Primitive conifers, ferns, giant rushes
• North America– Still at the equator, northwest Africa collides with
eastern North America to form the northern Appalachians & White mountains
• Common fossils– Coral reefs, jawless & armoured fish
MISSISSIPPIAN PERIOD
• Common fossils
– Crinoids (sea lilies) – starfish attached to the
sea floor
– Foraminifera (amoeba like single celled
animals) – tiny calcite shells
• North America
– Southern Appalachian mountains form
PENNSYLVANIAN PERIOD
• Age of Cockroaches
– Insects increase, large dragonflies & cockroaches
• 1st reptiles
– lizards
• North America
– Still at the equator
– Warm, wet climate floods eastern USA in huge
freshwater swamps – forming rich coalfields
– Continents continue colliding to form the Appalachian
mountains
PERMIAN PERIOD
• Dry climate
– Shallow inland seas evaporated leaving large
deposits of salt & gypsum
• Large reefs
– Coral, algae, sponges thrived
• Great southern ice age
– South America, Australia, South Africa, India
END of the PALEOZOIC ERA
• Pangaea forms– Continental crust welds together into one
supercontinent
• Mountains form– Appalachian & Ural mountains fully elevate
• 96% species extinction– Trilobites, eurypterids, coal forming seed ferns, scale
trees & primitive conifers - extinct
• 2 important survivors– Cephalopods (oceans) & reptiles (land)