Do amebelodon really have two sets of tusks (upper and lower) or do they just have big teeth on the bottom?

Question Answered by Sue Miller, Paleontologist

Amebelodon

“Shovel-tuskers” Way cool! They are ancient, now extinct, cousins of elephants. Their nickname comes from the shape of their large, flat and extended lower incisors and small upper tusks – instead of long and curved upper tusks like mammoths, mastodons, and modern elephants. They were about the size of a small modern elephant, and it is thought that they may have used the ‘shovel tusks’ to excavate plant roots and shave the bark from trees.


For some big words. The Genus Amebelodon is in the mammal kingdom, Family Gomphotheriidae, and Order Proboscidea, which includes several extinct genera – mastodons, mammoths, and modern Asian and African elephants.

They are known from fossils throughout the world, most continents, and from the east and west coasts and central United States. Unfortunately not from Idaho. Yet? We need to find the right rocks or sediments geology where their fossils might be preserved.

They were alive from the time period Early Miocene (20 – 23 million years ago) during warmer climates, until their extinction worldwide by the end of the Pleistocene (120,000 years ago). Amebelodon first appeared in the Great Plains and Gulf Coast regions of North America during the late Miocene, roughly 9 million years ago, and apparently became extinct on this continent sometime around 5 million years ago. Their disappearance most likely resulted from the effects of climate changes in the northern hemisphere leading to the onset of the Ice Age.

Fossilized Mammoth Molar

Resources:
Shoshani, J. and P. Tassy, eds. 1996. The Proboscidea: Evolution and Palaeoecology of Elephants and Their Relatives. Oxford University Press. Oxford, UK.
Carroll, R. L. 1988. Vertebrate Paleontology and Evolution. W.H. Freeman and Co. New York, NY
https://en.wikipedia.org/wiki/Amebelodon

Tusk vs Tooth – What’s the Difference?
Tusks are actually elongated, continuously growing teeth. Many animals have them in pairs and you’ll see them protruding well beyond the mouth in many animals. In most animals, these tusks are actually elongated canine teeth but in elephants, they’re elongated incisors.

Biologically, tusks aren’t different from teeth in ways other than size. Like teeth, they have blood and nerves inside and enamel on the outside. Unlike the rest of an animal’s teeth, though, tusks continue to grow throughout their lives.

Tusks can be used in many ways in the animal world. Boars and warthogs use theirs offensively and defensively, to battle one another during mating season and to slay predators many times their size.

Walruses use their tusks like grappling hooks to haul themselves out of the water and onto the ice, as weapons against polar bears, and in mating competition.

Narwhals remain a bit of a mystery with some researchers suggesting they use it to stun their fish prey while others suggest it is some sort of sensory organ for detecting changes in the water.

Elephants use their large tusks to do a variety of things including digging for salts and minerals, breaking off branches to get to the foliage, prying into trees and peeling off the bark, and even scooping up a sleeping little one who is refusing to get up. They use their tusks along with their trunks and feet to de-thorn acacia trees and soften tough grasses and they stash leafy branches across their tusks for later consumption.

Scientists, called paleontologists, act like detectives to learn about past animals and environments. Paleontologists can use the marks found on fossil teeth and tusks to help determine the diet of that animal.

Materials: 8 bars of soap, twig with leaves, sandpaper fold (so both sides are rough), piece of bark, corn husk, black watercolor paint and paintbrush, a friend

  1. Hold 2 bars of soap (teeth) and sandwich the twig with leaves (food) between the teeth and then have your friend pull it out. Hold the soap down just hard enough to get a good impression on the soap, but not so hard your friend can’t pull the twig out.
  2. Repeat Step 1 with the sandpaper, bark and corn husk.
  3. Examine the impressions. If you’re having a hard time seeing them, brush a little paint over the impression to define the marks on the soap. Can you tell which food each of the set of teeth “ate”? How can paleontologists use this kind of information when looking at marks on tusks and teeth?

From Tusks! Florida Museum of Natural History

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