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Mesozoic Era (Age of the Dinosaurs). 225,000,000 years ago to 65,000,000 years ago Warm Climate Three Periods Triassic Jurassic Cretaceous. Triassic Period (225-180 MYA). Pangaea (supercontinent) formed. Triassic Period (225-180 MYA). First Dinosaurs (small in size). - PowerPoint PPT Presentation
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Mesozoic EraMesozoic Era(Age of the Dinosaurs)(Age of the Dinosaurs)
225,000,000 years ago225,000,000 years ago toto 65,000,000 years ago65,000,000 years ago
Warm ClimateWarm Climate
Three PeriodsThree Periods
TriassicTriassic
JurassicJurassic
CretaceousCretaceous
Triassic Period (225-180 MYA)
Pangaea (supercontinent) formed
Triassic Period (225-180 MYA)
First Dinosaurs (small in size)
Triassic Period (225-180 MYA)
Conifers and Cycad Forests Dominate (Gymnosperms)
Jurassic Period (180-135 MYA)
Pangaea starts to separate
Jurassic Period (180-135 MYA)
Dinosaurs Dominate: Allosaurus, Diplodocus, Brachiosaurus, Stegasaurus.
Jurassic Period (180-135 MYA)
Reptiles in the sea - Icthyosaurs – 8 m; Plesiosaurs – 15 m.
Jurassic Period (180-135 MYA)
1st mammals (small rodents).
Jurassic Period (180-135 MYA)
1st birds (Archaeopteryx).
Cretaceous Period (135-65 MYA)
Continents in modern positions
Cretaceous Period (135-65 MYA)
Dinosaurs still dominate: T. rex (carnivore); Triceratops (horned); Trachadon (duck-billed)
Cretaceous Period (135-65 MYA)
Angiosperms (flowering plants with fruit) evolve & dominate
Cretaceous Period (135-65 MYA)
Mass Extinction: 50% of all plant and animal groups die
Alvarez’s Meteor Impact Theory- iridium layer (common in meteors), dust blocked out the sun.
Cenozoic EraCenozoic Era(Age of the Mammals)(Age of the Mammals)
65,000,000 years ag65,000,000 years ago to to Present Dayo Present Day
Two PeriodsTwo Periods
TertiaryTertiary
QuaternaryQuaternary
Tertiary Period (65 MYA to 1.8 MYA) Warm and humid climate
Mammals dominate: increasing in size
Angiosperms (flowering plants) dominate
Grasses develop, grazing animals become even larger
Earliest prehistoric humans (approximately 3.5 MYA).
Animals of the Tertiary
Organisms that have been found in the La Brea tar pits of Los Angeles
Megatherium, a giant ground sloth (20 ft long).
Animals of the Tertiary
Indricotherium, measured up to 13 ft at the shoulder.
Diatryma, a giant predatory bird.
The Great Ice
Age
Quaternary Period (1.8 MYA to Present)
The “Great Ice Age”, ice sheets covered 30% of all land
Land & ice bridges connected many continents allowing animal migration
North American elephants (mastodons, mammoths), giant sloths & armadillos, and saber-toothed cats go extinct.
Modern humans evolve, maybe causing the above extinctions from hunting.
A Sixth Mass Extinction?
• Are we the cause of a sixth mass extinction that is currently taking place?
– Round Table Discussion