Let's suppose you've decided to make a name for yourself in
cryptozoology. Everyone and their chupacabra is out looking for sasquatches and
lake monsters. Your way to fame will be through finding your own monster and
carving out your own turf. So you pack up your extra grainy, black and white
camera (the preferred tool of cryptozooligists everywhere) and head off to a
lost valley in Montana known only to you and the wizened shaman who told you
about it. After a day of fruitless searching, you're heading back to camp. It's
that hour between day and night when the light is at its most deceptive.
Suddenly, you hearing a crashing the underbrush and there it is. It's the
biggest animal you've ever seen! It's covered with long hair! It has a trunk
and tusks! You've discovered the last mammoth! Or mastodon. Are they the same
thing? If they're not, what is the difference?
First of all, they are not the same thing. They are not even
that closely related. They are two different species, in two different genera,
in two different families of the order Proboscidea. They are about as closely
related as you and a ring-tailed lemur. Today, the order Proboscidea is
represented by three species, in two genera of the same family, but, in its
evolutionary history, the order has produced at least two suborders, eight
families, thirty eight genera, and almost two hundred species. At the end of
the last ice age, the number of poboscidean species wandering the earth was in
the high teens. They inhabited every continent except Australia and Antarctica.
They lived in forests, prairies, jungles, around the edges of deserts, and out
on the tundra. They could be found on seacoasts, islands, and high in the
mountains.
If mastodons are way over there, where is the mammoth?
Mammoths, and there have been about eight species, have their own genus,
Mammuthus. They split off from Asian elephants (genus Elphas) about six million
years ago. This was after the latter split off from African elephants (genus
Loxodonta). At the time, all three genera lived in Africa. As mammoths moved
north from Africa into Europe and Asia, they gradually evolved from one species
into another to adapt to new climates and in response to the world cooling into
the ice ages.
Eventually, two species of mammoth made their way into North
America. Yes, two. There is nothing simple about elephant evolution. The steppe
mammoth (Mammuthus trogontheri) evolved in northeastern Asia somewhat less than
two million years ago. This was early in the ice ages. This species was adapted
to a cool dry climate. It spread to the north and west. The northern group
crossed the Bering Straits during a period of low sea levels--that is, just
before or just after a glacial period when lots of water is still locked up in
ice caps, but the climate in Alaska is still somewhat temperate (my own opinion
is that it was after a glacial maximum). This group moved into North America
and adapted to grasslands and lightly forested areas. In time, it populated
most of the contiguous US and Mexico down to the valley surrounding Mexico
City. This population, adapted to a temperate and we call the resulting species
the Columbian mammoth (Mammuthus columbi).
The steppe mammoths that stayed in Asia eventually spread
back across the grasslands of central Eurasia (the steppes) all the way to
Ireland and Spain. These mammoths adapted to the coldest climate. They became a
keystone species involved in creating an Arctic grassland in areas that are now
tundra. We call this lost ecological system, the mammoth steppe. As opposed to
the current steppe which runs through central Eurasia south of the forest zone,
the mammoth steppe existed in the dry, cold region north of the forests. These
mammoths became shorter and stockier that other than the Columbian mammoth.
Their hair became longer and the developed a layer of wool next to their skin.
AS you may have guessed, this is the woolly mammoth (Mammuthus primigenius).
During an interglacial period about 500,000 years ago, a population of these
mammoths crossed into North America. During the last few glacial periods, they
created mammoth steppes on both sides of the American ice sheets, in the
northern US states and Canadian prairie provinces and in Alaska and the Yukon.
Okay. I understand the mammoths. What were the mastodons doing
during all of this? Mastodons were going nuts, creating new species left and
right. The ancestors of mammoths and mastodons split from each other early in
the evolution of Proboscidea, possibly over forty million years ago. The
majority of proboscid species are on the mastodon side of the order. The
ancestors of mastodons entered the New World long before mammoths, possibly in
more than one wave. There were three or four species living in South America
when humans arrived and the best known species (Mammut americanum) living in
North America. Mastodon remains have been found all over the forty eight
contiguous states and as far south as Honduras.
We're finally there. We have mammoths and we have mastodons
and we have them living side by side in North America. Doesn't that pose a
problem? How can you have two large hungry animals filling the same ecological
niche? The answer is: you almost never can. Mammoths and mastodons didn't fill
the same niche. Forty million years of separate evolution produced two similar
looking animals, but the two animals had different feeding habits. Mammoths
were primarily grazers. The ate grasses and herbs. They can eat other plant
matter, such as tree bark, but their teeth and digestive systems are best
suited for ground plants. Mastodons were primarily browsers. They ate mostly
leaves and small branches. Where we have found gut contents for mastodons, it
has been mostly made up of conifers such as pine, spruce, and fir. Mammoths
were found mostly on prairies and grasslands and mastodons in boggy forests.
There would have been some overlap around the edges of their ranges, but no
extensive contact.
Mammoth tooth discovered during the Thirty Years War. Source.
The first evidence of this difference was their teeth.
Mammoths, like elephants, had big loaf shaped teeth made up of parallel plates
that were used to grind their food. They had one in each jaw, for a total of
just four. Grinding eventually destroys the teeth, so they grew a new pair
every ten years or so. Mastodon teeth look more like a familiar molar. They
were enamel covered and had high knobby cusps. They had two in each jaw, for a
total of eight. This kind of tooth is good for tearing branched apart.
When large numbers of mastodon bones arrived in Europe in
the Eighteenth Century, the teeth presented a problem. The ivory and other
bones made it easy to recognize it as similar to elephants and mammoths. Were
the remains found in some unique place where mammoths came to die, leaving all
their bones, except the teeth, and where some other large animal came to die,
leaving none of its bones, except the teeth? Putting the teeth and skeletons
together as a single animal created a particularly horrifying image. Molars
with pointed cusps, like the mastodon had, were thought to be a sign of meat
eating. Some of the published descriptions of the animal imagined it pouncing
on entire herds of buffalo and tearing them to shreds.
Mastodon tooth found near the Ohio River in 1739. Source.
By the end of that century, people like Ben Franklin on this
side of the Atlantic and Baron Cuvier on the other, had managed to convince the
scientific community that mastodons and mammoths were distinct species,
separate from elephants, and, almost certainly, extinct. That last part was a
disturbing idea that bordered on religious heresy. Extinction implied that
God's creation came with extra, unnecessary parts. This flew in the face of how
Europeans conceived of creation. The world, to them, was a perfect machine.
Every part had its own mysterious purpose. Superfluous parts meant the world
was not perfect and, possibly, that God was not perfect. Many flat out refused
to believe that extinction was possible. These animals had to still exist in
some unexplored corner of the world. When Thomas Jefferson sent Lewis and Clark
to explore the headwaters of the Missouri river and continue on to the Pacific
coast, his instructions explicitly included orders to look for mammoths and
mastodons.
From the above, you've probably guessed that the chief
determiner of their uniqueness was the teeth. When Baron Cuvier presented the
paper that was seen as the final word in the argument, he coined the name
mastodonte. The etymology is from the Greek "masto" meaning breast or
nipple and "dont" meaning tooth. Cuvier thought the cusps of the
teeth look breast like. He probably needed to get out more often. Jefferson, with
his American charm, called the mastodon "bubbie toothed." Cuvier was
too late with his name. Just a few years earlier, his peer Joseph Blumenbach
had taken the initiative in giving the two extinct animals Linean binomials.
The mammoth, he thought, was too close to the Asian elephant to deserve
separate genus. He named it Elphas primigenius, meaning the primeval, or first,
elephant. This was factually wrong. Woolly mammoths evolved much later than
Asian elephants. The mastodon, he confusingly named Mammut americanum, meaning
American mammoth. When paleontologists eventually decided to put the woolly
mammoth in its own genus, along with later discovered mammoths, they named it
Mammuthus primigenius which is still wrong because it was the last mammoth.
Let's get back to your budding cryptozoology career. The
beast in the brush did not stop long enough to give you a big toothy grin so
you could figure out its dietary preferences. Don't worry, despite two
centuries of bad illustrations making them look the same, there are significant
enough differences in appearance to make an identification. Thanks to finding
almost intact frozen mammoths, we know more about them than any other
prehistoric, extinct animal. This includes details of their appearance. We know
what their ears looked like and what the very tips of their trunks looked like.
We don't know as much about fine details of mastodon appearance, but we know
enough.
A very nice person made this and donated it to Wikipedia. Source.
Woolly mammoths have a distinct and well known profile.
Their back slopes down from their shoulders to their hips. This is not formed
by and great difference in the length of their legs. Instead, it is caused by
long dorsal spines on their thoracic vertebrae. This humped area is used to
store fat for the winter. The woolly has a high domed head tight against its shoulders
and tusks that begin pointing almost straight down before making a tight
corkscrew curl back up almost to eye level. Columbian mammoths differ from
woollies by being taller. Their legs are longer and the hump is less
pronounced. Their hair probably wasn't as dense as on the woolly.
Mastodons had shorter legs and longer bodies than either
mammoth. The line of their back was fairly straight. Their heads projected
further forward as did their tusks. The curve of the tusks was more like those
of modern elephants. Baby mastodons had short tusks in their lower jaws, though
they shed these when their adult teeth came in and reshaped their jaws.
Mastodons probably had longer tails than woolly mammoths, though you would only
notice that if you saw them together. Like the Columbian mammoth, mastodons
didn't have fur as thick as the woolly's wool.
There you have it, the key to a good photographic
identification of a mammoth or mastodon is to catch them in profile, maybe in
the crest of a hill, silhouetted by the setting sun. Good luck with that.
