First Life • The first life forms on Earth did not need oxygen. Who or what were these organisms? How about _________ !!!!!!!!!!!!!!!! _________ are not complete organisms. They need other organisms to provide nutrients to live SO!!!!!!!!!!!!!!!!!
First Life
• The first life forms on Earth did not need oxygen.
Who or what were these organisms?How about _________!!!!!!!!!!!!!!!!_________ are not complete organisms.
They need other organisms to provide nutrients to live
SO!!!!!!!!!!!!!!!!!
2.5 b.y.a.
• Oxygen build up primarily due to organisms that perform photosynthesis.
• These photosynthetic organisms are called _________.
• Today cyanobacteria live in all green plants and are called?
_________
• Most of the first oxygen reacted with iron forming _________(rust).
• Once the available iron finished reacting, oxygen began to accumulate in the atmosphere.
• _________ began to accumulate in the atmosphere about 2.5 billion years ago.
• Ocean dwelling organism appeared in the fossil record about 540 million years ago (m.y.a.).
Precambrian Fossils
_________ – are layered mounts of calcium carbonate, which are the remains of material deposited by algae.
Paleozoic Era: Life Explodes
The Paleozoic ear is made of several periods including:
• Permian – youngest period• Pennsylvanian• Mississippian• Devonian • Silurian• Ordovician • Cambrian – oldest period
Early Paleozoic History
During the Cambrian, Ordovician, and Silurian periods, the vast southern continent of _________ included:
• South America• Africa• Australia• Antarctica• India• And perhaps China
North America
• was most likely on or near the equator.
• had no living things, plant or animal.
• Later on North America collides with Africa beginning the formation of the Appalachian Mountains and continues for 200 million years.
• By the Silurian period, shallow seas or epicontinental seas covered much of North America.
• Many barrier reefs prevented circulation between the shallow marine basins and the open ocean.
• As the water evaporated salt and gypsum deposits formed.
_________ 2.7 b.y.a
• We now have the basic part to make all forms of life
• We just need to make things more and more complex
• _________ must adjust to do different kinds of jobs
What is the name of the 1 celled life form in the oceans?
• _________
•represents all animal life to come
• _________
•represents all plant life to come
Plankton – 1.8 b.y.a.
Colonial organisms
• _________ critters that are not very specialized
_________ _________ -
(polyps)_________
Early Paleozoic Life
Life at this time is restricted to the oceans. All forms of life were invertebrates.
1- _________ – bottom dwelling scavengers. They occurred in more than 600 types. They were the _________ form of life at this time.
Paleozoic Era - Cambrian period
Dominant form of life is the trilobite
A. Body segmentsB. Head shieldC. Tail shield
2 – _________ – these shelled organisms replace trilobites as the dominant form of life. Except for one species, brachiopods are extinct today.
• Their larvae were free swimming, but like oysters and clams, these shelled animals were attached to the ocean floor.
Paleozoic Era - Cambrian period
•brachiopods are present [ forerunner to the _________]
3 – _________ – cousin to the octopus and squid. These highly mobile _________ were the major predator of the time.
• Cephalopods were the first large animal on Earth.
• By the end of the Ordovician many organism were able to secret material to form hard parts such as an exoskeleton.
Paleozoic Era –Ordovician505 – 440 m.y.a.
•cephalopods (_________)
oldest one is the _________
Late Paleozoic
The tectonic reorganization of Earth’s landmasses into one supercontinent called _________.
Late Paleozoic History
• North America collides with Africa closing the narrow sea that separated them.
• As this collision continues the rest of the Northern Hemisphere continents join them.
• This resulted in the formation of the northern continent of _________.
• By the Permian, Gondwana has traveled north and collides with Laurasia.
• By the end of the Paleozoic _________ is formed.
Late Paleozoic Life
• Plants living at the water’s edge move onto the land.
• These plants were leafless vertical spikes about the size of your index finger.
• By the end of the Devonian Period (40 million years later) there were forests.
• The first forests were in _________ …..
_________
First primitive fish_________
Paleozoic Era – Silurian440 – 410 m.y.a.
• Appearance of _________ water fish.• 1st land critters appear and
were????? _________
Including: _____________________________________________
Paleozoic Era - Devonian Known as the AGE OF FISHES
• _________
_________ __________________
• _________
all modern fish
• Amphibians diversified on land because they had no major competitors.
• By the Pennsylvanian period large tropical swamps extended across North America, Europe, and Siberia.
• Coal deposits today resulted from these swamps.
Lobe fin became the ancestor of
_________