MegafaunaMegafaunaBy: By:

Laura ProvostLaura Provost

Pasquale Quintero Jr.Pasquale Quintero Jr.

SpeciesSpecies

About 48 species of About 48 species of Megafauna lived in Megafauna lived in North America during North America during the Pleistocene Epochthe Pleistocene Epoch

MammothMammoth MastodonMastodon Saber-Toothed CatsSaber-Toothed Cats Giant SlothGiant Sloth Short Faced BearShort Faced Bear Dire Wolf, etc.Dire Wolf, etc.

SpeciesSpecies

MammothMammoth Genus Genus MammuthusMammuthus Three species of Three species of

mammoth: Columbian mammoth: Columbian Mammoth, Jefferson’s Mammoth, Jefferson’s Mammoth, Woolly Mammoth, Woolly Mammoth Mammoth

10-12 feet high10-12 feet high Weighed between 6-8 tonsWeighed between 6-8 tons 1.8 mya first mammoths 1.8 mya first mammoths

entered into North Americaentered into North America 10 kya, all species of 10 kya, all species of

mammoth went extinctmammoth went extinct

MastodonMastodon

Mammut Mammut americanumamericanum

8-10 feet high8-10 feet high Weighed between Weighed between

4-6 tons4-6 tons Lived in North Lived in North

America from America from about 3.7 mya to about 3.7 mya to 10 kya10 kya

Saber-Toothed CatsSaber-Toothed Cats

Two species lived Two species lived in North America: in North America: Saber tooth Saber tooth genus: Smilodon, genus: Smilodon, and Scimitar cat and Scimitar cat genus: genus: HomotheriumHomotherium

Saber Tooth CatSaber Tooth Cat

Canines were 7 inches longCanines were 7 inches long Size of modern African lion, but Size of modern African lion, but

anatomically differentanatomically different Short, powerful legsShort, powerful legs Not built to run fast or farNot built to run fast or far One possible use for canines: bite throat or One possible use for canines: bite throat or

abdomen of large preyabdomen of large prey Other use for canines: as a social displayOther use for canines: as a social display Went extinct 11 kyaWent extinct 11 kya

Scimitar CatScimitar Cat

Canines 4 inches longCanines 4 inches long About the size of modern African lion, About the size of modern African lion,

but anatomically differentbut anatomically different Long forelimbs, long neck, and short, Long forelimbs, long neck, and short,

powerful hind legspowerful hind legs Combined strength and speedCombined strength and speed Chased more prey than the Saber Chased more prey than the Saber

ToothTooth Went extinct 11 kyaWent extinct 11 kya

Giant SlothGiant Sloth

Four species of Four species of ground sloths in ground sloths in North AmericaNorth America

Jefferson’s ground Jefferson’s ground sloth, Laurillard’s sloth, Laurillard’s ground sloth, ground sloth, Shasta ground Shasta ground sloth, and Harlan’s sloth, and Harlan’s ground slothground sloth

Ground SlothsGround Sloths

Spent all of their Spent all of their time on the time on the ground, unlike ground, unlike modern slothsmodern sloths

About the size of About the size of an oxenan oxen

Very large clawsVery large claws All were herbivoresAll were herbivores Went extinct about Went extinct about

10 kya10 kya

Short Faced BearShort Faced Bear

Extremely large, Extremely large, weighed 13 weighed 13 hundred poundshundred pounds

Approximately 10-Approximately 10-12 feet tall12 feet tall

Went extinct 11 Went extinct 11 kyakya

Dire WolfDire Wolf Belonged to genus Belonged to genus Canis, Canis,

includes: wolves, coyotes, includes: wolves, coyotes, jackals, and domestic dogsjackals, and domestic dogs

About 5 feet longAbout 5 feet long Weighed about 110 poundsWeighed about 110 pounds Looked familiar to modern Looked familiar to modern

grey wolf, but had larger, grey wolf, but had larger, broader head and shorter broader head and shorter legs, teeth were more legs, teeth were more massivemassive

Teeth may have been used Teeth may have been used to crush bonesto crush bones

Went extinct about 10 kyaWent extinct about 10 kya

Pleistocene Pleistocene Pleistocene Epoch followed the Pliocene EpochPleistocene Epoch followed the Pliocene Epoch Transition marked by decrease in rainfall linked Transition marked by decrease in rainfall linked

with the spread of ice at high latitudeswith the spread of ice at high latitudes Pleistocene began when ice started to cover a Pleistocene began when ice started to cover a

large part of northern hemispherelarge part of northern hemisphere Ice built up because as the northern continents Ice built up because as the northern continents

drifted to higher latitudes they sealed off the flow drifted to higher latitudes they sealed off the flow of warm water into the artic ocean, causing the of warm water into the artic ocean, causing the top of the ocean to freezetop of the ocean to freeze

Once frozen it reflected incoming solar heat away Once frozen it reflected incoming solar heat away in the summer and caused artic weather in in the summer and caused artic weather in surrounding areassurrounding areas

OriginsOrigins

Megafauna crossed a glacial land bridge Megafauna crossed a glacial land bridge connecting Siberia and North Americaconnecting Siberia and North America

12 kya humans migrated from Asia into 12 kya humans migrated from Asia into the new worldthe new world

Megafauna ExtinctionsMegafauna Extinctions 48 species went extinct at the end of the 48 species went extinct at the end of the

Pleistocene Epoch (11 kya) weighing over Pleistocene Epoch (11 kya) weighing over 20 pounds; three of every four species of 20 pounds; three of every four species of megafauna greater than a 100 pounds megafauna greater than a 100 pounds went extinctwent extinct

For the next 10 kya not a single For the next 10 kya not a single mammalian species went extinct from mammalian species went extinct from North America North America

Scientists believe there are two major Scientists believe there are two major factors for extinction of the megafaunafactors for extinction of the megafauna

Climate hypothesis vs. Overkill hypothesisClimate hypothesis vs. Overkill hypothesis

Climate hypothesisClimate hypothesis Habitat destruction is one of the major causes of extinctionHabitat destruction is one of the major causes of extinction About 15-10 kya the climate in North America was changingAbout 15-10 kya the climate in North America was changing Temperatures were warming, rainfall patterns changed, Temperatures were warming, rainfall patterns changed,

glaciers were melting, and seasonal changes were glaciers were melting, and seasonal changes were increasingincreasing

The more open diverse forest and nutritional substances The more open diverse forest and nutritional substances were being replaced by denser forest with little diversity were being replaced by denser forest with little diversity and nutritional valueand nutritional value

This forced many megafauna species to leave their habitats This forced many megafauna species to leave their habitats because the new environments had lower carrying because the new environments had lower carrying capacities for the large mammals capacities for the large mammals

The megafauna could not adapt to the changes in their The megafauna could not adapt to the changes in their environmentenvironment

Climate HypothesisClimate Hypothesis

Scientists believe that there is not enough Scientists believe that there is not enough evidence to support the Overkill evidence to support the Overkill hypothesishypothesis

Only 15 sites containing Clovis points have Only 15 sites containing Clovis points have been found in North Americabeen found in North America

Kill sites containing Clovis points all Kill sites containing Clovis points all contain either Mammoth or Mastodon contain either Mammoth or Mastodon bones, but there is no evidence of early bones, but there is no evidence of early Americans hunting other large mammals Americans hunting other large mammals such as ground sloths, short faced bear, such as ground sloths, short faced bear, etc. which also went extinctetc. which also went extinct

Overkill HypothesisOverkill Hypothesis Animal populations were not evenly Animal populations were not evenly

distributed through out North Americadistributed through out North America The route taken by early Clovis through The route taken by early Clovis through

the Bering Land Bridge brought them out the Bering Land Bridge brought them out directly in the middle of the range of the directly in the middle of the range of the megafaunamegafauna

Mammoth and Mastodon killings led to an Mammoth and Mastodon killings led to an environmental collapse for smaller environmental collapse for smaller megafauna megafauna

After extinction of large megafauna After extinction of large megafauna humans had to rely on smaller animals, humans had to rely on smaller animals, such as deersuch as deer

Overkill HypothesisOverkill Hypothesis

The only two other predators of the The only two other predators of the mammoth and mastodon, besides man mammoth and mastodon, besides man were the saber tooth tiger and short face were the saber tooth tiger and short face bear, both of which went extinct 1 kya bear, both of which went extinct 1 kya years beforeyears before

““Records from islands show that human Records from islands show that human colonists cause extinction; therefore, colonists cause extinction; therefore, Clovis people caused extinction.” –Retired Clovis people caused extinction.” –Retired University of Arizona Ecologist, Paul MartinUniversity of Arizona Ecologist, Paul Martin

Disease Hypothesis Disease Hypothesis

Clovis hunters or their dogs carried with Clovis hunters or their dogs carried with them a deadly microbethem a deadly microbe

Larger species (megafauna) cannot Larger species (megafauna) cannot replace their offspring fast enoughreplace their offspring fast enough

Smaller animals that breed often Smaller animals that breed often survivedsurvived

SourcesSources Gribbin, John and Mary. Gribbin, John and Mary. Children of the Ice: Climate and Children of the Ice: Climate and

Human OriginsHuman Origins. Cambridge, MA: Basil Blackwell, 1990.. Cambridge, MA: Basil Blackwell, 1990. Stone, Richard. Stone, Richard. Mammoth: The Resurrection of an Ice Age Mammoth: The Resurrection of an Ice Age

GiantGiant. Cambridge, MA: Perseus, 2001.. Cambridge, MA: Perseus, 2001. Ward, Peter D. Ward, Peter D. The Call of Distant Mammoths: Why the Ice The Call of Distant Mammoths: Why the Ice

Age Mammals DisappearedAge Mammals Disappeared. New York: Copernicus, 1997.. New York: Copernicus, 1997. http://www.museum.state.il.us/exhibits/larson/content.htmlhttp://www.museum.state.il.us/exhibits/larson/content.html http://www.beringia.com/index.htmhttp://www.beringia.com/index.htm http://www.amonline.net.au/factsheets/megafauna.htmhttp://www.amonline.net.au/factsheets/megafauna.htm http://www.mnsu.edu/emuseum/prehistory/hunters/http://www.mnsu.edu/emuseum/prehistory/hunters/

index.shtmlindex.shtml http://www.washington.edu/newsroom/news/2001archive/http://www.washington.edu/newsroom/news/2001archive/

10-01archive/k102401.html10-01archive/k102401.html