Welcome to Class Write down the four eras (put them in the correct order)
Post on 29-Dec-2015
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Agenda for Today
• Hand back tests-go over– Correct tests
• Go over periods and epoch (notes)
• Create a travel brochure
Change Over Time• Scientists have discovered evidence of livings things
changing over time
• evolution - inheritable change in the characteristics within a population from one generation to the next– development of new types of organisms from
preexisting organisms– Evolution occurs by natural selection
• Major geologic and climatic changes can affect the ability of some organisms to survive.
• Use geologic evidence to determine how environmental changes affected organisms in the past.
Cambrian• Marine invertebrates-trilobites,
brachiopods
• Other organisms include jellyfish, worms, snails, and sponges
Ordovician• Brachiopods and mollusks started to thrive
• Vertebrates appear – jawless fish
Silurian
• Sea stars and coral
• Land plants appear
Devonian• Many fish appear-bony, some could
breathe air, others possibly made it to land
• Ferns, horsetails abundant
Carboniferous• Warm• Forests, swamps cover
most of the area• Fish and amphibians• First Vertebrates on land
Permian• Pangea comes together
– Lose the seas=mass extinction– Reptiles and amphibians survive
Triassic
• Dinosaurs present• Ammonite fossil
common = index fossil
Jurassic• 2 groups of dinosaurs evolved
– saurischians, or “lizard-hipped” – Ornithischians, or “bird–hipped”
Cretaceous• Common Cretaceous dinosaurs were T-Rex,
the ankylosaurs, the ceratopsians, and the hadrosaurs
• Flowering plants appeared
Cretaceous-Tertiary Mass Extinction
• No dino fossils found after Cretaceous
• Impact Theory
Cenozoic Era
• Quaternary– Pleistocene– Holocene
• Tertiary – Paleocene– Eocene– Oligocene– Miocene– Pliocene
Paleocene and Eocene Epochs• New mammals, such as
rodents, evolved• Early ancestors of the
horse, whales, flying squirrels, and bats, evolved
• Temp dropped 4ºC at the end of the Eocene
Oligocene and Miocene Epochs
• Became significantly cooler and drier – Antarctic icecap began to form
• Early mammals became extinct• Large species of deer, pigs, horses, camels, cats,
dogs • Grasses, cone-bearing, and hardwood trees
Pliocene Epoch• Animals such as bears, dogs, and cats,
evolved into modern forms• Herbivores flourished• Continental ice sheets began to spread
– Bering land bridge and the Central American land bridge formed = migration
Pleistocene Epoch• Ice sheets advanced and retreated several times
– Animals need thick fur– Migrated to warmer regions– Became extinct
• Fossils of modern humans were discovered– Evidence they hunted
Holocene Epoch
• Began as the last glacial period ended– ice sheets melted, sea level rose about 140 m, and the
coastlines took on their present shapes• Modern humans develop agriculture and began
to make and use tools made of metal
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