A New “Lady” in Town, Part I: Why Priscilla the mastodon isn’t a mammoth at all

“It’s the biggest gosh darn mastodon I ever saw! Wowzah!

Yes, that’s a direct quote.

It wouldn’t be a lie to say it’s hard to surprise our esteemed Dr. Bob Bakker, Curator of Paleontology. (That would be me.) But Priscilla did it.

“It’s H-U-G-E ! You could fit a Diplodocus torso inside this rib cage!”

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I was standing under the capacious hips of our new cast Mammut americanum, better known as “the American Mastodon.” The stupendous backbone and legs were being hoisted up on cables so the Black Hills Institute staff could attach the head. Mind you, we at HMNS are no strangers to the mastodon — we’ve had a fine cast of a bull on display in our old hall. Big, formidable.

But Priscilla is way off the scale — in life, twice as heavy as the average bull Mammut. And far more massive than our new Columbian mammoth who will co-star in the new fossil hall.

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I’m getting ahead of myself, so let’s back up for a second.

What exactly is a mastodon? And how’s it different from a mammoth (because it is, you know)?


North America has two fossil mammoths. The famous woolly mammoth, star of the Ice Age movies, lived in the far north, close to the glaciers. The Columbian mammoths were taller and even heavier and stayed further south, away from the frigid realms. For two million years, Columbian mammoth clans and mastodon were neighbors. They’re found together in many Texas Ice Age sites, at the famous La Brea Tar Pits, and scores of other excavations from Florida to Oregon as well.

Sure, from a distance, the mammoth and mastodon do seem similar. Both have big bodies, bulgy bellies, straight legs, short necks and compact skulls with a hole in the forehead where the long trunk attached in life. The tusks are long and curved and there is just one well developed pair in the upper jaw. (Mastodons might have tiny tusk vestiges in the lower jaw too.)

When they were alive, both would run with long strides with their weight supported by wide five-toed paws embedded in thick, cushiony pads. Both would move their limbs in that unusual gait employed by modern elephants — right fore and hind swung back together and forward together, while the left fore and hind went forward when the right limbs went back. And vice versa.


But the mastodon clan and the mammoth clan separated some 25 million years ago. The short skulls, long upper tusks and well-developed trunks are mostly evolved in parallel from an ancestor who had long jaws and four long tusks — two in the upper jaw, two in the lower.

All mammoths really are genuine elephants, very close kin of the Asian elephant you see in zoos — that’s why scientists trying to clone a woolly mammoth from frozen specimens in Siberia hope to use the egg from a female Asian elephant.

All mammoths have elephant-style molars. Each tooth crown is a gigantic vegetable processor, with many vertical plates of enamel set in a mass of dentine and cement. (Clever system.) As the uppers and lowers grind against each other, the cement and dentine wear away faster than the enamel. So, the enamel ridges stick up a bit more, guaranteeing that the tooth still has multi-edged cutting/chopping/mincing action until the tooth is totally worn out.

Now look into the mouth of our American mastodon and you’ll see the outstanding difference. The teeth are much smaller and simpler and have nothing like the food-processing power of a mammoth’s grinder. Each mastodon tooth is like a human molar or a pig molar. There are four or six main cusps in two rows, one inside and one outside. The total volume of one molar is one-twentieth that of a mammoth of the same body size. And when the enamel outer covering wore away in a mastodon, there were no vertical ridges of enamel left to cut and chop.

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Clearly mastodons had to be more persnickety about their food choices than did the mammoths. Fossil stomach contents show that mammoths had an elephant-like diet: rushes, sedges, grass, branches, clumps of broad-leafed tree leaves. Stomach remnants and food bits caught between molars tell us that mastodons sought out soft bark from birch trees, soft branches, soft leaves, fallen fruit and nuts with just a wee bit of grass as a garnish.

After analyzing the dental differences, you’d predict that mastodons stayed in wetter, more wooded environments, rich in bushes and young trees. Mammoths would, on the contrary, penetrate far across the open meadows, grasslands and even deserts.

The census of fossil sites confirm your prediction.

Mastodon remains are abundant in bogs and swamps and sandbars from rivers flowing though forests. Mammoths, on the other hand, left many skeletons in sand dunes and rivers that flowed through open terrain. Occasionally both do occur in one spot, but usually one or the other dominates.

Stay tuned for Part II, where you’ll get to know Priscilla like you’ve never known a mastodon before.

100 Years – 100 Objects: Black Diamond

The Houston Museum of Natural Science was founded in 1909 – meaning that the curators of the Houston Museum of Natural Science have been collecting and preserving natural and cultural treasures for a hundred years now. For this yearlong series, our current curators have chosen one hundred exceptional objects from the Museum’s immense storehouse of specimens and artifacts—one for each year of our history. Check back here frequently to learn more about this diverse selection of behind-the-scenes curiosities—we will post the image and description of a new object every few days.


This description is from Dan, the museum’s curator of vertebrate zoology. He’s chosen a selection of objects that represent the most fascinating animals in the Museum’s collections, that we’ll be sharing here – and at 100.hmns.org– throughout the year.

During a circus parade in Corsicana, TX during the 1920’s, this famous elephant attacked members of the public audience while his handler wasn’t paying attention. 

What ensued after the attack would surely have been one of the strongest publicized cases regarding humane treatment of captive elephants.

You can see more images of this fascinating artifact – as well as the others we’ve posted so far this year – in the 100 Objects section at 100.hmns.org

Science Doesn’t Sleep (8.19.08)

Hungry dolphin
He really knows himself.
Creative Commons License photo credit: robertpaulyoung

So here’s what went down after you logged off.

I reflect, therefore, I am: commonly known in elephants, dolphins and great apes, self-recognition has long been deemed a key determinate of advanced cognitive abilities in animals. Now, we’ve discovered that magpies can do it.

Back to school: kids are still savoring the last days of summer, but teachers spending their first days back at HMNS, soaking up science and learning ways to use the exhibits here to bring science to life for their students next year.

Another humpback whale is lost; this time, a calf, in the waters outside Sydney. It’s bonded to a yacht, and if an adult female doesn’t come by soon, it may not survive.

No wonder bees are dying in record numbers: their hives are filled with pesticides.

Coming soon – Robots: part of a balanced diet.

The 1918 flu epidemic killed between 20 – 100 million people worldwide; survivors of the epidemic alive today still have circulating antibodies to the disease, 80 90 years later.

An old wive’s tale that’s somewhat true: severe morning sickness increases the possibility of delivering a baby girl.

Science Doesn’t Sleep (8.14.08)

Granny Smith
Nutritous and delicious.
Creative Commons License photo credit: Steve Navarro

So here’s what went down after you logged off.

For the 2008 Olympians, what’s nutritious and delicious? Powdered apple peel.

Humans and wild elephants in Indonesia have come into repeated conflict over habitat – resulting in property losses for humans and deaths of wild elephants. So, locals have developed a squadron of trained “flying elephants” that patrol the perimeter villages and warn their brethren away.

Insects that dive underwater create an “underwater lung” – an air bubble they carry with them as they swim – in order to breathe. Scientists have just figured out how it works.

Don’t forget to sleep on it: sleep plays a sophisticated role in what we remember – and what we forget.

Geographic profiling: what works for bees also works for serial killers.

Ready the wonderment: the Moon goes into partial eclipse this Saturday night.

Where have all the sea monsters gone? A variety of factors are transforming Earth’s oceans into “simplistic ecosystems dominated by microbes, toxic algal blooms, jellyfish and disease.”