Pleistocene Extinction Affected the Pleistocene Megafauna Affected the Pleistocene Megafauna Only land mammals Only land mammals Happened about years ago Happened about years ago Affected all of the continents Affected all of the continents

Megafauna North America North America Mammoths Mammoths Mastodons Mastodons Horses Horses Camels Camels Ground sloths Ground sloths Glyptodonts Saber-toothed cats Short-faced bears Dire wolves

Megafauna South America South America Hoofed mammals Hoofed mammals NA immigrants NA immigrants Eurasia and Africa Eurasia and Africa Saber-toothed cats Saber-toothed cats Wooly rhinos Wooly rhinos Australia Australia All giant marsupials All giant marsupials

Causes: Overkill Extinctions peaked at a time when humans arrived in NA Extinctions peaked at a time when humans arrived in NA Evidence of horses and camels being hunted Evidence of horses and camels being hunted Opposition Opposition Bison were hunted, around today Bison were hunted, around today Extinctions started in NA before Bering Land bridge Extinctions started in NA before Bering Land bridge

Causes: Overkill Humans evolved alongside African megafauna, still around Humans evolved alongside African megafauna, still around Australian extinction happened before humans came to continent Australian extinction happened before humans came to continent

Causes: Environmental Transition Land started to transition from glacier to interglacial Land started to transition from glacier to interglacial Land went from mild and uniform to drier and seasonal Land went from mild and uniform to drier and seasonal Plants started to go extinct Plants started to go extinct Animals that depended on them died out Animals that depended on them died out

Other Causes Combination Combination Loss of food plus hunting overwhelmed some species Loss of food plus hunting overwhelmed some species Keystone Species Keystone Species In East Africa, African Elephants keep grasslands open In East Africa, African Elephants keep grasslands open When they were wiped out by poaching, brush grew in place of grass When they were wiped out by poaching, brush grew in place of grass Grassland mammals disappeared Grassland mammals disappeared

Other Causes Mastodons and mammoths may have played same roles as elephants Mastodons and mammoths may have played same roles as elephants Humans may have hunted them to extinction Humans may have hunted them to extinction Cascade effect on extinction of other animals Cascade effect on extinction of other animals