Mammoth teeth are very interesting to look at. Each tooth is composed of thin enamel plates cemented together to make tall, strong and wear-resistant teeth. This type of tooth is very useful in grinding up coarse vegetation such as grass. Grasses tend to contain tiny particles of the element silicon, which is what glass is made of. These particles of silicon act like sandpaper, and wear down the teeth of the animals that feed on the grasses. The construction of mammoth teeth does not make them immune to wearing down by silicon, but it does make them more resistant.
As we'll see in my next article about mastodons, their teeth are very different from mammoth teeth. The way I remember the difference is to say, "Mammoths have many labyrinths," and that reminds me of the labyrinthine shape of their teeth.
About 10,000 years ago, many large mammals became extinct in North America and elsewhere. This Late Pleistocene extinction killed mostly animals that were larger than 44kg (100 lbs), such as the saber-toothed cats, mammoths, and mastodons. It also led to the extinction of the horse and the tapir in North America, although they continued to live elsewhere. This extinction event is why North America has a relatively low diversity of large mammals in comparison to other continents.
Recently, a team of French scientists recovered the fully preserved body of a 20,000-year-old woolly mammoth from the permafrost of Arctic Siberia. The scientists plan to slowly thaw the animal out, so they may be able to analyze its fur, internal organs and other soft tissues, and to maybe even recover some DNA.
After the successful cloning of Dolly the sheep and other animals, it has been hoped that scientists might be able to clone extinct animals from DNA that has been preserved this way, by freezing. One difficulty that any cloning attempt would face is that mammoth DNA has 58 chromosomes, while modern elephants have 56 chromosomes. The good news is that, despite the difference in chromosome number, there is only a 5-percent genetic difference between the two species so cross-breeding could theoretically be possible.
But don't rush out to your nearest zoo to look for cloned mammoths. The French scientists expect that it will take up to three years to slowly thaw out the mammoth and at least two years after that before any offspring would be born, due to the long gestation period of elephants. Be sure to read my article "Cloning Extinct Animals I" for more information about the difficulties associated with attempting to clone mammoths and other extinct animals.
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