Clovis – and Earlier

Of the archeological sites which are considered to have signs of pre-Clovis human activity there are four that I want to focus on today, for a reason, which I’ll get to in a minute.

When and how people first came to the New World has long been an archeological mystery.   Whenever the first Europeans arrived here (either in 1492, and thereafter, or earlier, if you prefer, with Leif Ericsson), they found people already living here.  But where had they come from?  And how?  And when?

Beginning in the 1920’s and thereafter, archeologists (and others) began finding large uniquely shaped stone spear points, and thought, “Aha! Here is evidence of the first people to inhabit the Americas.”  The points were unique in that they had a distinctive fluting, which permitted the point to be hafted onto a shaft.  (See the illustrations.)  The first of these archaic points was found near the town of Clovis, New Mexico, and the culture that had created these beautiful tools became known as the Clovis culture. crain-clovis-hh1Clovis Point

The scientists knew these points were old, because, for example, they found some wedged in mammoth bones.  And as dating techniques became more refined, the points were dated to roughly thirteen thousand years ago. [1] At the time of the discovery of the Clovis points, and for a long time after that, that there was no evidence of any human occupation before that time, roughly 13,000 years BP (Before Present).  

So, based on the discovery of these old stone tools, and the absence of evidence of an earlier human presence, the predominant theory developed.  The theory is often called the Clovis First theory.  That theory was fairly straightforward:  During the last glacial maximum, between sixteen thousand and twelve thousand years ago, the sea level was so low that Siberia and Alaska were connected by a vast land bridge called Beringia; and the people who made those Clovis points, the first humans to come into the Americas, had walked across that land; had come here from Siberia, down through Canada, and into the Americas.  And the theory was plausible, because at that time, not only were the seas low enough to permit travel from Siberia to Alaska on foot, across the vast land today known as Beringia, but also, because at that time there was an ice-free corridor which would have let the wanderers pass down from Alaska between the glaciers, and so into Canada, and the rest of the Americas. And, at that time there was no evidence to suggest that people had been here earlier.

Thus, the Clovis First theory says that those people, who came across Beringia between sixteen thousand and twelve thousand years ago, were the first people to enter North America.  And it was thought, that by 13,000 years ago, they and their culture had diffused as far south as Clovis, New Mexico.

It was a very neat theory.  And, for that matter, it’s a theory that may well reflect (a part of) what really happened.  That is to say, it is likely that some people did, in fact, come into the Americas via Beringia, during that time.

But – it may be that that was not the only way that people got here; and it also may be that people got here earlier than previously thought.

Cue four sites of human settlement in the Americas:

Meadowcroft, Pennsylvania

Saltville, Virginia

Cactus Hill, Virginia

Topper, South Carolina

Why?  Why these four sites?

Two reasons:

First, each has evidence of human activity earlier than 13,000 years ago; evidence of the human presence before the Clovis First theory  permits.

One of the interesting things about archeology is that it isn’t like going to a museum.  The discoveries are not complete little villages, all laid out in a neat diorama.  There are no complete sets of bows and arrows, just lying around.  The materials discovered are often fragmentary, contradictory, and require detailed analysis, and some level of conjecture, before inferences may be drawn, and tentative conclusions reached.

To a greater or lesser extent each of these sites is controversial, insofar as each purports to show evidence of human activity before 13,000 years BP, in large part because the evidence is so equivocal.  I’ll review the sites in greater detail later, but for now, it’s sufficient to state that each shows (or claims to show) evidence of human activity much earlier than the commonly accepted dates of Clovis culture.

How much earlier?    A million years?

Five hundred thousand years?

One hundred thousand years?

Nope.  Three thousand years, four maybe, maybe five thousand years, maybe a little more.

I’ve oversimplified a little.  As noted above, these sites are dated using radiocarbon analysis and that method generates different dates than calendar dates.  There are formulas, however, which allow radiocarbon dates to be translated, roughly, into calendar dates, and using that conversion factor, we can derive evidence of human activity at these sites that goes back as far as 20,000 years BP.

Now that is not hundreds of thousands of years, not even tens of thousands of years, but it is thousands of years.  Thousands (plural) of years.   That’s a long time.  Christianity is only two thousand years old; the pyramids were built five thousand years ago.  And we’re back way before that, and, for that matter, way before the Clovis dates.  Thousands of years earlier.

As I say, each site is somewhat controversial.  But let us assume, for now, that they accurately show evidence of human activity thousands of years before Clovis culture developed.

That leads to the second reason to consider these four sites:

Look where they are.  They’re all on the east coast.

They are thousands of miles away from Clovis, New Mexico; thousands of miles away from the ice-free corridor which led down through Alaska and Canada into North America.  These sites are way over in the east.

Somebody did some traveling.

Somebody traveled far enough to be way over in Virginia, thousands of years before the Clovis culture began.  Who?  Where’d they come from? How’d they get here?

These sites therefore, are significant for a number of reasons:

First, they show evidence that there were people here thousands of years earlier than the Clovis First theory posits.

Second, they show that those people, (whoever they were, however they got here, whenever they got here), were widely spread out across North America.

Third, the locations suggest that people must have entered North America much earlier than the dates posited under the Clovis First theory, in order to give them enough time have travelled so far.

But look at this cool map here.[2]

Bering Strait1

See how it shows routes of travel?  The first Americans could go anywhere they wanted (subject to the location of the ice sheets during the various ice ages).  Don’t makethe mistake of thinking that just because Clovis points were first found in New Mexico that that was where the Clovis culture began.  It’s not as though the first people came over the land bridge, directly down to Clovis, New Mexico, devised this new stone technique and then spread out from there.  In fact, Clovis points have been found all over America, and there is no single answer to where it began.  

Still, it is interesting that once was once considered the first record of the peopling of the Americas is now being superseded by evidence of human inhabitation of the Americas much earlier than originally thought, from sites that are very widely diffused.

I’ll bet you’d like the answer, huh?  Who were these people? When did they get here?  How?

Stick around.

 

 

 

 


[1]Dates are commonly obtained by radiocarbon dating, and the dates are given as RCYBP, which stands for RadioCarbon Years Before Present.  Radiocarbon years do not exactly equal calendar years. Under that measure Clovis culture is thought to have begun about 11,500 RCYBP.  This translates, however (roughly) to 13000 – 135000 years ago. The whole radiocarbon dating/time scale conversion issue is well beyond the scope of this blog, or this blog entry at least.  So for now, let’s just agree that Clovis culture began sometime around about thirteen thousand years ago.

 

[2] I found this map in the article “Prehistoric Migration of American Indians,” by (I think) Katherine Bolman, BS, MFA, MEd, MSW, EdD., at Arthistoryworlds.org.  The map itself is attributed to Jose Arredondo.  The link to the website is http://arthistoryworlds.org/prehistoric-migration-of-american-indians/.

 

 

The Door Opens

It was a simple story, and probably – probably – too good to be true.

Two great vast continents standing open, uninhabited, alone, separated from the rest of the world by two enormous oceans, until the glaciers came, and drew down the sea level hundreds of feet, and so exposed a bridge, a wide corridor of land stretching between and connecting Siberia and Alaska.  And no mere footpath – this now-submerged land, Beringia, was hundreds of miles wide, steppe country, treeless, covered with grasses, and sedges, and dwarf willows.  Huge clouds of mosquitos swirled over the ponds and streams that ran across the land, but they were not sufficient to bother the great herds that walked that land – the reindeer, the caribou, the horses, and bison, and mammoths, and mastodons.

Gallery_Image_6245-2

And where the game went, the story goes, the people followed. Up and up, north and east into the shining sun, in the long, long days, following the herds.  North and east, ever on, until those people were no longer in Siberia, but now, in Beringia, and sometime later, in Alaska.  And then Canada, and the land stood open, and they came in, and so peopled North America.  Following the game across the land.

A simple story and a beautiful one.

This is the theory that has dominated thinking about the peopling of the Americas for decades.  These first Americans, so the theory goes, were associated with a specific type of spear point, called a Clovis point, after the town in New Mexico where the ancient points were first discovered.  And they arrived in North America sometime – roughly – no one knows for sure – between 11,500 and 13,500 years ago.

But – Is the story true?  Was that how and when people came to the Americas?  And if true, still other questions remain – was that the only way that they came here? And was that the only time?

Because there are anomalies.  There are doubts.  There are questions.

There are, in short, other theories, and tantalizing hints of evidence to support them.

From the lack of any fossil evidence whatsoever, it is reasonable to conclude that until quite recently both North and South America were entirely uninhabited.  And humans didn’t evolve here.  Yet when Columbus arrived, he found people here; earlier, when the Norsemen came, they found the skraelings – human beings. So somehow, at some point, humans made their way here, into the Americas.  But how?  And when?

There are really only five ways they could have come.  When the glaciers were in full flower, the ocean level was so low that that land bridge, Beringia – hundreds of miles wide – formed between Siberia and Alaska.  Maybe, following the game, bands of people came through that way, and then down through Canada.

Two: Maybe they sailed along the coast between Siberia and Alaska, and then on down the coast.

Three – maybe some people – maybe – sailed along the edges of the glaciers from Europe to Iceland, then Greenland, and island hopped along the Canadian coast and down into north America.

Four – maybe bold sailors sailed right across the Pacific.

Five – maybe equally bold sailors sailed right across the Atlantic.

Maybe they came in different ways at different times. And maybe they came in waves.  The problem is, we just don’t know.

But there is tantalizing evidence that suggests that the Clovis model is overly simplistic, and probably not entirely accurate.  This is not to say that people didn’t come over the land bridge we call Beringia – they probably did.  But when they came, and whether that was the only was they got here, remain unsettled.  The questions remain:

When did people first come to the Americas?  How?

Over the next several entries, these are the questions I’ll be looking at.

 

 

 

The Giant Sloths – An Unlikely Success Story

Ground sloths were large quadrupedal mammals that were predominantly herbivorous (more on that later).  They evolved in South America, before continental drift had joined North America to South America, and then, managed to cross the land bridge in Central America and make it all the way into North America.  In fact, remains of ground sloths have been found in Alaska.  Not bad for slow-moving, ponderous vegetarians.

20090421130214-megatherium

There were many, many species of ground sloths; something like 80 genera, and above that, at least six families.  As you may recall from the last entry; a species is a single type of animal, a genus a grouping of closely related species, and a family a grouping of several different, but related genera.  So ground sloths, although ungainly looking, as will be discussed below, were quite successful – not a fluke, or trick of evolution.  I should note, of course, that there is still some confusion about just which fossil remain of a given sloth falls into which family, and genus.  Nonetheless, the ground sloths, as a whole, were quite successful, and evolved into many different shapes, sizes, and habitats.

Perhaps the best known of the now extinct ground sloths was megalonyx jeffersonii, best known, if it’s known at all, because of its association with President Thomas Jefferson, for whom the species is named.  President Jefferson was an avid naturalist, and paleontologist, who received fossil specimens of the ground sloth that bears his name, in 1796-97.  These included some gigantic claws (of which, more later).  He suggested that they were a species of lion, and suggested that the as-yet undiscovered animal be named megalonyx, or giant claw.  In fact, when Lewis and Clark set out to explore the Louisiana purchase in 1804, Jefferson asked them to look out for megalonyx, which he thought might still be alive somewhere in the unknown west.  He was wrong.  The claws were not from a lion, but from the sloth, and the sloths were extinct.  Nonetheless, his boundless curiosity, and suggestion that discoveries of this sort were worthwhile, remain commendable.

OLYMPUS DIGITAL CAMERA

M. jeffersonii, was enormous – eight to ten feet long.  And it weighed up to 2000 pounds.  Like the other ground sloths, it was herbivorous, and ate leaves, branches and bark it stripped from trees.

Big as it was, however, megalonyx was dwarfed by another giant sloth – Megatherium.  This animal was formidable.  It grew at long at twenty feet, and weighed up to four metric tons.  A metric ton is roughly 2,204 pounds, so an adult megatherium might have weighed almost 9,000 pounds.  You know what else weighs that much?  Elephants.

sharp_hutchinson_megatherium

Megatherium was confined to South and Central America, but its close cousin, the slightly smaller Eremotherium ranged into southern North America.

I wrote that they were herbivorous, and that is undoubtedly true.  There is some thought, however, that they may also have been opportunistic carnivores, perhaps flipping glyptodonts (think Volkswagen-sized, turtle-shaped mammals) over, to get to their soft underbelly, or even chasing active predators away from kills, in order to scavenge the carcass.  These theories are still quite controversial, and await further testing or discovery for clarification.

These were big, ungainly, slow-moving creatures.  And yet, they thrived.  They walked on all four legs, but could sit upright, to reach up into trees.  Some could stand on their hind legs like bears.  And they were armed with long, sharp claws on their front legs.

They apparently lived in family groups, and presumably the parents would have protected the young.  But it seems unlikely that they were herd animals.

So why are these animals interesting?  There are several reasons:

First, as will be discussed in a later post, when South and North America joined, more animals native to North American spread into South America, than did animals coming north from South America.  Sloths were among the relatively few species that migrated north, out of South America.  Why?

Second, why did they, like so many of the other animals of this time period, become so large?  Presumably, in North America, they were expanding into an otherwise vacant ecological niche, so they had no direct competition.  But they had evolved in South America, where there was competition, and still they grew to enormous size.  Why?

Third – how did they evolve?  They don’t seem like a likely candidate for evolutionary success, these big, slow-moving herbivores.  But they were very successful, for thousands and thousands of years.  Were those claws that deadly?  Did no animal selectively prey upon them?

Finally, as with so many other species of Pleistocene animals, we are left to wonder – what happened to them?  Remains of giant sloths have ben found in association with human hunting – so evidently humans were a species that preyed upon them.  And perhaps, human hunting pressure, combined with a low or slow reproductive rate were sufficient to drive them to extinction.  Climate change, too, may have played a role.  Whatever the reason, they are all gone now – extinct.

But imagine how happy President Jefferson would have been if Lewis and Clark had found a Megalonyx for him.

When Muskoxen ruled the Earth

Muskox (Ovibos moschatus), picture taken on 30...

Muskox (Ovibos moschatus), picture taken on 30 October 2004 in Dovrefjell National Park, Norway (Photo credit: Wikipedia)

Okay, that’s not true.  That’s a lie.  Muskoxen never ruled the earth.  I just said that to catch your eye.

But – Muskoxen did live here.  Not just up in the high arctic, but here, where we are – in the continental United States, in California, New Jersey, Texas, Missouri, Oklahoma.  They were everywhere.

So, let’s spend a moment talking about muskoxen, scientific name: Ovibos moschatus.   Sometimes called the tundra muskoxen.  And, yes, the plural of muskox is muskoxen.   And apparently, one can spell the name of the great beast as either muskox (one word), or musk ox (two words).  Ditto muskoxen (or musk oxen, if you will).

There are still muskoxen today, mostly living up in the Canadian arctic and Greenland, although a few introduced populations exist elsewhere in the polar north, including Sweden and Alaska.

And, despite their appearance, they are not oxen.  They are more closely related to sheep and goats.

They’re big, standing 4 to 5 feet at the shoulders, weighing 500 to 900 pounds.  Both the males and females are armed with those sharp, curved and deadly horns.  Both sexes are covered with thick shaggy pelts, with guard hairs that almost reach the ground.  They’re the ones who form a protective ring around their young when threatened by predation from wolves.

The name comes from the strong musky scent of the males.

Big, shaggy, razor-sharp horns, and they smell:  What’s not to love?

To my eye, they look primitive, atavistic, survivors from a by-gone era.  And that’s just what they.  They’re believed to have come into North America one hundred to two hundred thousand years ago, across Beringia, the land bridge that connected Siberia to North America, when the ocean levels were hundreds of meters lower, due to the Ice Age.  And then, during the extinction event of eleven thousand or so years ago, their range shrank dramatically:  While they had previously been widespread in the circumpolar north, they disappeared, save for those living in northern North America.  From there, they gradually spread north and east, arriving in Greenland around 350 A.D.

The map shows the distribution of muskox. The ...

The map shows the distribution of muskox. The red colour shows the “original“ distribution of muskoxen (in the beginning of the 19th century). The blue colour shows the areas where muskoxen have been introduced with success in the 20th century. (Photo credit: Wikipedia)

They were contemporaries of the mammoth, the mastodon, all of the other (now-extinct) megafauana.  But unlike so many other species, the muskox survived, and did not go extinct.

Yet.

Today there are fewer of them, and less genetic diversity than before.   They may be on the long slow road to extinction.  Maybe not.  Check back with me in fifteen or twenty thousand years.

-But –

They’re not the muskoxen I want to talk about today.

Today, I want to talk about a closely related species of muskox, a species now extinct:  The helmeted muskox, Bootherium bombifrons. 

This one – the helmeted muskox – was the one that was here; the one that lived in New Jersey, and Texas, and California until about 10 or 11 thousand years ago.

This one is ours.  This muskox appears to have evolved and lived only here, in North America.

Its closest relative is the tundra muskox living far to the north today,  but the helmeted muskox was significantly different.

For one thing, it was bigger; taller, anyway.  It stood five to six feet at the shoulders.  But it was leaner than Ovibos.  Its skull was thicker, and its snout was much longer.  And its horns –those curved, pointed, killing weapons -were fused on the top of its head, forming a great bony plate.  Ideal for head-butting your rivals when it’s mating season.  This anatomy differs from that of the tundra muskox, whose horns are separated from each other by a groove, although the tundra muskox engages in serious head-butting during the rut, too.

Like the tundra muskox, the helmeted muskox had a coat of dark brown hair, but its was shorter and finer than that of Ovibos.

As mentioned above, its remains have been found all over – but not a lot of them, not many fossils.  So, although they were widely distributed, there apparently weren’t vast numbers of them.

And, as is so often the case with extinct animals, much about them is not known.  There is, for instance, some question about its preferred habitat.  It seems likely, however, that it preferred open wooded areas, or savannah-like habitats, where it could eat a varied diet of grasses, woody plants, and shrubs.  So, a generalist, not dependent on a single food source.

It was here, throughout the United States, moving through open woods, probably in small herds, rutting, mating, raising its young, forming a defensive ring to stand off wolves or other predators; grazing or browsing on shrubs.

And yet, it is extinct, while its close cousin, the tundra muskox, survives.  Why?  There aren’t a lot of fossil remains, but it doesn’t seem likely that hunting was the primary reason for its extinction (although it certainly may have been a contributing factor).

Climate change?  Probably.  But the details are unclear.  Lots of large animals went extinct roughly ten, eleven thousand years ago, but not all of them:  Not the moose, not the bison, not the pronghorn, and not the tundra muskox.  So why did the helmeted muskox disappear?  It was  widespread, had a varied diet – what happened to wipe it out?  One theory, and it is only a theory, is that it got squeezed between the tundra muskox – better adapted for life in the far north; and the bison – better for life in open woods.  But I don’t know.

Let me know if you find out.

And one last thing:  The helmeted muskox was NOT the only muskox species to live here.  There was another, a giant:  The Shrub-ox, Euceratherium collinum.  It was huge, much bigger than the muskox or helmeted muskox.  But that is a report for another day.

Wait – This is not an elephant!

Q.  When is an elephant not an elephant?

A.  When it’s a mastodon.

The American Mastodon.  Its remains have been found from Alaska to Florida, New York to California.  Fishermen find their teeth when their nets dredge the ocean bottoms one hundred miles offshore, suggesting that their range was even greater when ocean levels were lower than at present.

Mastodons might have seemed, at first glance, like elephants.  Like modern elephants, they had trunks, and tusks.  But although they were in the same order as elephants, they were in a different genus – Mammut.  Their build differed from modern elephants – they had shorter legs, longer bodies, and were more heavily muscled.  They stood between 7 ½ and 10 feet tall at the shoulders, and weighed up to 10,000 pounds. There is fossil evidence of sexual dimorphism – males were larger, on average, than females.

Mastodon

Image from Oliver, The American Mastodon, New England’s Extinct Giant, June 9, 2011, www. onenewengland.com

Mastodons had big tusks, up to fifteen feet long.  They were curved, but not as sharply as those of mammoths.  And they were used in combat. They were aggressive. Fossil evidence shows that the males engaged in fierce battles, presumably fighting over access to the females.

And like the woolly mammoth, the American Mastodon had a thick woolly fur coat.

American Mastodon compared to Woolly Mammoth

Masatodon v. Mammoth

Image from http://en.wikipedia.org/wiki/File:MammothVsMastodon.jpg

File this in the “betcha didn’t know” category:  “Mastodon” means “breast-tooth,” or “nipple-tooth,” because of the cone shaped protrusions on its teeth.  These suggest that the mastodon diet was largely browse – leaves, twigs and branches from trees, shrubs and bushes.

There is some controversy about their behavior.  Many experts think they lived in herds, probably females and young, much like modern elephants.  Others’ however, think they may have been more solitary animals.

They disappeared roughly twelve thousand years ago, possibly because of climate change, aided by hunting pressure from humans entering the continent at that time.  Archeologists find skeletal remains with Clovis points embedded in them.  Mastodons were hunted.  They are extinct now.

Would have been cool to see one, though.

This are two short excerpts from my novel, The Clovis Mission:

Another valley.  We were in basin and range country, now.  Another stream, and a small lake behind a beaver damn.  Aspen growing.

And then, in the night, in my vision goggles, I saw them. Three of them, browsing on the aspen. Mastodons. Yeah, I know, I should call them Mammut. So sue me.  Much less tall than the mammoths, but built like boxcars, with a long sloping spine from the head to the tail.  No hump.  But long, and wide.  Very solid.  Long, long tusks, but straighter than those of the mammoths. Just browsing in the margin of the woods.  They, unlike the other animals we had seen recently, seemed entirely unconcerned with us. Their small piggish eyes tracked me as I rode past, and one snorted a little, but they didn’t move, either toward us or away. 

I surmise that they were m. cosoensis, not m. americanum, because there were only three of them, not a herd, and because they were browsing aspen leaves, not spruce needles.  But so little is known.  Maybe they break up into family groups during the summer.  Maybe their diet changes seasonally, and they take advantage of whatever forage is available at any given time of year.  Maybe they were an as-yet unknown subspecies. 

But, oh, what a sight.  So large, solid, rocking a little as they browsed, their trunks curling up and stripping the small branches off the aspens.  Their fur was long and shaggy, but they too, like the mammoths, were shedding their winter coats.

***

The screaming shocked me.  A huge, high, squalling, screaming blast. It came from up ahead, but our vision was obscured by a grove of trees.  As the three of us rode past the trees though, I saw what had caused the noise.  Two mastodon bulls were facing off, both equally large, heavy, strong, and ready, apparently, for a fight.  Not with us – with each other.  Mating season.  The rut. They were only about ten feet apart.  The one with his back to us was lashing his tail.  The trunk of the other was waving in the air.  Both were shaking their heads from side to side.  Beyond them, in the near distance, several cows stood placidly.

Again the screaming blast. And they closed with one another fast and hard.  They slammed into one another, piston legs driving, slashing and stabbing with their tusks, pushing with their heads.    A cloud of dust arose around them from the impact.  The fight was swift and savage.  Neither backed down for several seconds.  Then they separated, and again smashed into each other. They twisted sideways, each seeking some purchase, some advantage.  And again they separated, and again smashed together.  This time, though one slipped the guard of the other, and his tusk drove into the shoulder of the other.  The injured bull screamed and backed off.  But again they charged.  And again.  And again.  Only the injured shoulder started to tell on the one bull.  He slipped sideways a little.  The other bull was relentless.  He kept pushing forward, slamming his trunk against the other’s, twisting his tusks furiously, trying to find another opening.  And again, he slipped the guard of the other.  This time, though, his tusk drove deep into the chest of the injured bull.  With that, the injured bull had had enough. He backed away, and started to turn, to flee.  But the victor would not stop.  He slammed forward again, into the side of the other bull.  Both tusks drove into the bull’s side, and he staggered, but did not fall.  When the victor backed out, the injured bull moved off at the fastest walk he could.  The victor lumbered after him for twenty yards or so, and then finally relented.  He stood for a moment, breathing heavily, then raised his trunk and bugled another loud cry.  The injured bull walked past the females and disappeared in the woods beyond them.

Fossil evidence shows that mastodons fought, but seeing this battle  – so shockingly raw, and sudden, and real- was a far cry from fossil ribs showing healed fractures.

That’s me, on the horse there.  This is what I saw, twelve thousand years ago, in my ride across country, from where St. Louis now stands, to Arizona.