RSS
 

Mammoth Facts

Mammoth Origin and Evolution

Our knowledge of mammoths is based on the fossil record and our knowledge of modern elephants.

Order Proboscidea (includes all elephants)

  • Proboscideans evolved ~50 million years ago (mya)
  • Proboscis = long flexible snout
  • 165 species

Mammoths are NOT closely related to mastodons. Mastodons evolved ~25 mya and are quite different from mammoths in size, diet, structure, and habitat. Mammoths are also NOT the ancestors of modern elephants. Elephantids split into 3 main groups (making them like first cousins) ~3-5 mya

  • Mammuthus (mammoths – now extinct)
  • Loxodonta (L. africana = modern African elephant)
  • Elephas (E. maximus = modern Asian elephant)

Mammoths occurred originally in Africa, then moved north into Europe and Asia. The steppe mammoth evolved into woolly mammoth. The woolly mammoth traveled into North America via the land bridge (Central Beringia) ~1.8 mya. The ancestral mammoth traveled into North America and evolved into columbian mammoth.

Principia’s Mammoth

  • Woolly Mammoth (Mammuthus primigenius), or Jefferson’s Mammoth (Mammuthus jeffersonii)
  • Male, based on tusks
  • Massive tusks; ~6.5 ft long
  • Mature, based on teeth (39-43 years in African Elephant Years)
  • M3 molars; number of plates tell us his age, amount of wear on molars refines his age
  • Flat molars for grinding grass
  • 10.7 feet tall at shoulder (3 times the length of the humerus)
  • Ate ~300 pounds of vegetation a day
  • Weighed ~ 6 tons
  • Head is 12-25% of body weight (short neck, but long nose to reach ground)

Geology

  • Buried in wind-blown silt, or loess, which blankets bluffs
  • Silt, derived from glacial deposits in flood plain, accumulated from 12,000-55,000 years ago
  • Our mammoth is in the upper part of the loess, so it is estimated to have died ~17,500 years ago

Climate & Habitat

  • Ice Age
  • From 1.65 million years ago to ~10,000 years ago
  • This area – last glacier melted about 125,000 years ago
  • Climate – cold, windy at times (dust storms)
  • Habitat – tundra-like steppe environment, grassland

How Did They Survive the Cold?

  • Hairy coat – 3 layers
  • Outer guard hairs – coarse, 3’ long in places
  • Underfur – thinner, shorter, 10-12″ long
  • Thick layer of wool next to skin – 1-3″ long
  • ~4″ of fat beneath its skin to insulate it
  • Small ears and short tail (less heat loss)

Comparing Mammoths, Mastodons, and Modern Elephants

Ancestral mammoth (Mammuthus meridionalis)

  • 13’ tall
  • lived in warm tropical forests
  • died out as climate cooled
  • Steppe mammoth (Mammuthus trogontherii)
  • 14’ tall
  • became extinct

Columbian mammoth (Mammuthus columbi)

  • 13’ tall, weighed 10 tons
  • low-latitude temperate grasslands
  • large ears

Woolly mammoth (Mammuthus primigenius)

  • 11’ tall, weighed 6-8 tons
  • cold arctic steppe (grassland)
  • head high-crowned
  • grazer
  • Jefferson’s mammoth ( Mammuthus jeffersonii )
  • Intermediate between Columbian and Woolly

Mastodon (Mammut americanum) (not a mammoth)

  • shorter, stockier – 8-10’ tall
  • head more sloped
  • teeth had pointed ridges/cones à browser
  • ate branches, twigs, leaves, roots, melons

African elephant (Loxodonta africana)

  • 10’ tall, weighs 6 tons (up to 11 tons)
  • big ears shaped like Africa
  • no domes on head
  • back dips in the middle
  • longer legs than Asian elephant
  • teeth like mammoth – flat

Asian elephant (Elephas maximus)

  • shorter, weighs 5 tons
  • smaller ears
  • double domes on head
  • rounded or hump-shaped back

Extinction of Mammoths by 11,000 Years Ago

Four theories:

  1. Dramatic climate change that affected vegetation patterns and hence, food source
  2. Over-hunting by humans
  3. New diseases introduced by animals and humans crossing on the land bridge from Siberia – no direct evidence exists to support this
  4. Meteorite impact

Many scientists believe that it was a combination of the first two theories – climate and humans – that caused the extinction of mammoths and many other large mammals by around 11,000 years ago.

Comments are closed.