Animals of the Pleistocene

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Animals of the Pleistocene

• Mastadons, Mammoths, Giant Sloths, Saber Tooth
  Cats

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Mastadons

• Became extinct about 11,000 years ago
• The American mastodon (scientific name Mammut
  americanum) roamed North America from at least
  3.75 million to 11,000 years ago.
• Mastodons, along with mammoths and modern
  elephants, are members of the order Proboscidea.
• As adults they stood between 2.5 and 3 meters
  (8-10 feet) at the shoulder and weighed betweeen
  3500 and 5400 kilograms (4-6 tons).

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Mammoths

• Mammoths (genus Mammuthus) are extinct
  elephant-like animals that were adapted to cold
  weather. These herbivores (plant-eaters) had
  long, dense hair and underfur, large ears (but
  much smaller than modern-day elephants), a long
  proboscis (nose), and long tusks. Both the males
  and the females had tusks the tusks were really
  incisor teeth.
• Mammoths lived from about 2 million years ago to
  9,000 years ago, during the last ice age (the
  Pleistocene Epoch). This was millions of years
  after the dinosaurs went extinct. These huge
  mammals lived throughout the world.
• The various mammoths ranged in size from about 9
  ft (2.7 m) tall to over 15 ft (4.5 m) tall. Some
  species had tusks that were straight, some had
  tusks that were curved. The longest tusks were
  over 17 feet (5.2 m) long. The tusks were used in
  mating rituals, for protection, and for digging
  in the snow for food.

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The Difference

• Mammoths and MastodonsMammoths had longer tusks
  than mastodons, a wider head, a sloping back,
  flat, chewing teeth, a trunk with two finger-like
  projections, and were mostly taller. Mastodons
  evolved earlier and lasted longer in geologic
  time.

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Sabertooth Cat

• With their enormous, deadly-sharp canines,
  saber-toothed carnivores are well known to many
  people as frightening and ferocious predators of
  the Cenozoic. Surprisingly, there is more than
  one "saber-toothed cat." The sabertooth
  morphology has appeared several times during the
  history of the mammals.
• Why the enormous teeth? Certainly they were used
  in hunting, but opinions vary as to exactly how
  they were used. Some paleontologists have
  suggested that they were used to grab and hold
  onto prey. However, attacking a large herbivore
  this way could easily break the saber teeth and
  saber teeth that were demonstrably broken during
  an animal's lifetime are rare in fossil deposits.
  A more plausible hypothesis suggests that saber
  teeth were used to deliver a fatal ripping wound
  to the belly or throat of a prey animal.
  Sabertooth carnivores may not have tried to
  grapple with prey. More likely, they delivered
  one crippling stab wound and then waited for the
  prey to die.

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Giant Sloth

• A few thousand years ago the Americas were the
  land of giant ground sloths. They were a bit more
  impressive than their tree-dwelling cousins, but
  would probably have been equally odd-looking.
  Megatherium was a huge sloth, almost 6m long, and
  because it became extinct so recently, mummified
  skin and dung has been discovered in dry caves in
  North America helping to reconstruct exactly what
  it looked like and how it behaved.
• The biggest surprise has come from the fossilised
  trackways of Megatherium. These have revealed the
  amazing fact that these giants regularly walked
  upright on their hind legs. The giant sloths must
  have weighed almost four tonnes (nearly as much
  as an African elephant), and so walking on only
  two legs would have put a tremendous strain on
  their skeletons.