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South America during the PLEISTOCENE EPOCH. Brought to you by: Jesse Sean Mark Naomie. Our location is South America, and our time frame is 2.6 (ma) to 12,000 years. Introduction. Giant Pleistocene mammals. Introduction.
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South America during the PLEISTOCENE EPOCH Brought to you by: Jesse Sean Mark Naomie
Our location is South America, and our time frame is 2.6 (ma) to 12,000 years.
Introduction • Giant Pleistocene mammals
Introduction Darwin visited South America in 1832 and was amazed by the giant mammal fossils he found. Lestodon Pleistocene- The age of the giants
ENVIRONMENT • Pleistocene climate was marked by repeated glacial cycles where continental glaciers pushed to the 40th parallel in some places. It is estimated that, at maximum glacial extent, 30% of the Earth's surface was covered by ice. In addition, a zone of permafrost stretched southward from the edge of the glacial sheet, a few hundred kilometers in North America.
Each glacial advance tied up huge volumes of water in continental ice sheets 1,500 to 3,000 metres (4,900–9,800 ft) thick, resulting in temporary sea level drops of 100 metres (300 ft) or more over the entire surface of the Earth. • Creating an arid cold environment (about 7 degrees colder than todays) that had less vegetation.
Life Adaptations • BODY SIZE • The megamammals were mostly large herbivores • Weighing from 1 ton (900kg) to up to 6 tons (5000kg) • In comparison elephants around 2000kg • Not many predators • Mainly sabertooth and short faced bears • Could only prey on juvenile megamammals (>1000kg)
Life Adaptations • Limbs, Locomotion, and Habits • Glyphodonts (1000-2000kg) could gallop like large mammals (buffalo, rhino) • Extra muscular insertion in humerus bone to adopt bipedal postures • Ground Sloth • Bipedal as well • Megatherium sloth had large claws for digging tubers
Life Adaptations • Feeding Apparatus • Hypsodontry • Relative increase in crown height of teeth • Some sloths show teeth for vertical biting in order to cut • Later species of sloth shows shifts towards abrasive vegetation and horizontal grinding • For Mylodontidshypsodontry it shows shifts towards dealing with abrasive soil from digging
Other Interesting Facts • Darwin played a large role in triggering studies on the genealogical interpretation of the fossil mammal lineages, or on their palaeobiology. • Humans may have been present 29,000 years before present. • Great American Biotic Interchange • 3 million years ago • Connected what is now North and South America • Brought an exchange of plants and animals.