Say Cheese!

Carnivore (bobcat) Teeth, Photo by Karen Arnold, Pixabay
Carnivore (bobcat) Teeth, Photo by Karen Arnold, Pixabay

Today on Museum Bites we’re talking teeth.  Did you know teeth are the hardest substance in our body? These pearly little gems tear our food into tiny bits, come in handy if we need to fend off an attack, and provide a little pocket change when we hide them under our pillow.  Teeth are also a treasure trove of information. For over 5 million years, they have played a starring role in our evolutionary biology.

Herbivore (horse) teeth, Photo by BiniP, Pixabay
Herbivore (horse) teeth, Photo by BiniP, Pixabay

Museums are chock full of teeth, tusks, and fangs. Carnivores typically have long, sharp front teeth and serrated (think saw blade) molars.  This toothy combination is ideal for snatching and tearing apart prey. Herbivores, on the other hand, tend to have broad front teeth and ridged molars.  This combo is ideal for gnawing and grinding up fruit and tough plants.

Insectivore (hedgehog) Teeth, Photo by Alexas_Fotos, Pixabay
Insectivore (hedgehog) Teeth, Photo by Alexas_Fotos, Pixabay

Switch-hitting omnivores, like humans, sport a combination of tearing and grinding shaped teeth.  Insectivores (yes, that’s a thing) have thin, needle-like teeth, ideal for piercing and devouring insects. Yum!

Tooth shape can tell us what an animal is capable of eating, but not its actual diet.  The Nutcracker Man is an excellent example.  In 1959, Mary Leakey and her team excavated Paranthropus boisei, a 2 million-year-old hominid.  His large molars, powerful jaw, and pronounced cheekbones led Leakey to believe he consumed a steady diet of nuts and so he was dubbed Nutcracker Man.

Nutcracker Man, Photo by RegentsPark, Wikimedia Commons
Nutcracker Man, Photo by RegentsPark, Wikimedia Commons

 

Decades later, paleoanthropologists examined the microwear—microscopic pits and scratches—on Nutcracker Man’s tooth enamel.  A steady diet of nuts would yield a large amount of microwear and tear, but Nutcracker Man had only a scant amount.  Nuts apparently were not on the menu.  Scientists surmised he instead dined on soft foods, like fruit.

But this is not the end of Nutcracker Man’s story.  During childhood and adolescence, our teeth absorb molecules from the food we eat.  By looking at the carbon isotopes embedded in Nutcracker man’s tooth enamel, scientists discovered C4.  A shattering discovery!  The C4 isotope is associated with the grasses of the savanna. Nutcracker Man wasn’t whipping up fruit smoothies in the cool, misty forest. He was nibbling on grass and roaming the much warmer climes of the savanna.

Another example of how teeth can help us piece together the past comes from our good friend, Lucy and her fellow Australopithecus Afarensis.  The isotopes embedded in their tooth enamel revealed a significant change in their paleo-diet.  Originally, Lucy and her relatives dined on fruits and leaves from the forest, but eventually, they switched to the grasses of the savanna. This ability to adapt helped preserve Lucy’s species and was an important step in evolution.

1st Day of School-2006-resizedNext time you’re brushing those pearly whites, just remember teeth contribute vital information to understanding our past.

Fun Toothy Facts:  Getting our wisdom teeth removed is a rite of passage, but did you know 35% of the population does not develop wisdom teeth?  Anywhere from one to four of these final molars begin to emerge in our late teens or early twenties.  I only had three and my older brothers had a field day with that bit of info. Speaking of older brothers, watch the outrageous prank these two play on their little sister after she has her wisdom teeth removed, Millicent and the Zombie Apocalypse.

Next week, Museum Bites will be out on Spring Break. I’ll be back in April with new places and spaces.  Have a great couple of weeks!

Sources:

Archaeology.org

Cerling, TE, et al (2011), Diet of Paranthropus boisei in the early Pleistocene of East Africa.

Livescience.com

Oral Surgery of Utah

Ungar, Grine & Teaford (2008), Dental Microwear and Diet of the Plio-Pleistocene Hominin Paranthropus boisei.

Ungarlab.uark.edu

Webdento.com

WebMD

 

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