PALEOZOIC ERA

PALEOZOIC ERA
ABUNDANT FOSSILS BEGIN
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
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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)
Cambrian Period – Life in the Oceans
Trilobite – Index Fossil of the
Cambrian Period
Fossil Found in the
Burgess Shale
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
Ordovician Period – Life in the Oceans
Graptolite – Index Fossil of the
Ordovician Period
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
Eurypterid –
Index Fossil
of the Silurian
Period (a sea
scorpion)
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
Age of
Fishes
Marine Life of the Devonian Period
Formation of the Northern Appalachian Mountains
Flooding of the Land – Fertile Soil for Plants
Trees Taking Root on Land to Form
the 1st Forests
Trees of the Devonian Period
Extinctions of the Devonian Period
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
Crinoid
Attached
to the sea
floor
Foraminifera
Single-celled
Calcite shells
Animals of the
Mississippian Period
North America at the Equator
– Forming the Southern Appalachian Mountains
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
Age of the Cockroaches
Swamps Covering
Eastern North America
– forming coalfields
1st Reptiles
– the Lizards
North America at the Equator
– forming 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
Dry Climate of the
Permian Period
- Shallow inland seas
Large Coral Reefs
Large Reptiles of the
Permian Period
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)
Pangaea
– the Supercontinent