Were ancient people hunting gomphotheres in Mexico?

This is a very cool question. The fact that we’re even asking it is cool. Why?  Because archaeologists hadn’t found evidence of humans hunting gomphotheres in North America up to this point.  It means maybe the ecological and archaeological scene in ice age North America was even more complicated than we thought. It means we have more to learn.  I think that having more to learn is a gift we don’t always appreciate.

To start, what’s a gomphothere? They’re extinct now (bummer, because they were cool animals), but they were relatives of modern elephants, as well as their ice age cohorts, the mammoths and mastodons. And all these guys belong to a group of animals called proboscideans

Recent research by an international team of scientists revealed a possible link between Clovis culture and gomphotheres. (For a really helpful explanation of Clovis culture and its history of study by archaeologists, check this out.) This project started in 2007 when ranchers in Sonora, Mexico found some large bones and alerted scientists.  Archaeologists began an excavation of the site, and eventually they found not only gomphothere bones, but also Clovis tools.  These are readily identifiable tools, particularly the iconic Clovis spearpoint.  Several Clovis tools were found at the site, which is called, rather wonderfully, El Fin del Mundo (The End of the World).   Not only is this the most recent gomphothere known from North America, at 13,390 years, but if the bones and tools are indeed related to each other, this site would represent an interaction between humans and gomphotheres — the only one so far known in North America.

Exciting, right?  Exciting and not straightforward.  Welcome to the wonderful world of North American archaeology (and also science).  When you find tools or other artifacts together with bones, it can be really (really) tough to say for sure that they’re actually related.  Think of it this way: you might accidentally drop a penny as you’re walking down the street.  It could land next to a bottle cap that’s been lying there for 4 months.  And then they could lie there, side by side, for another few months, and someone else might find them both one day.  Does that mean you dropped the bottle cap?  Does it mean the penny and the bottle cap are somehow related?  Does it mean you know the person who dropped the bottle cap?  Does it mean the person who dropped the bottle cap caused you to drop the penny?  No, no, no, and no.  In other words, just because a couple of things end up in vicinity of each other doesn’t mean they have anything to do with each other, or that they did in the past. 

Fortunately, there are ways to be more sure about the relationship between artifacts and bones found at the same site.  You can look at the context.  What do the sediments say?  Was this an area with a strong water flow?  Was it a lake?  Were lots of things getting washed in from all over?  Was random stuff getting jumbled together?  Does it look pretty quiet, like mixing was minimal?  If you’re looking at soils, were they moved around a lot by burrowing animals?  Did older stuff and younger stuff get mixed?  Or are the strata pretty much intact?  Asking these questions of the site and taking a good hard look at the sediments will help a worker to know whether the bones and tools could be related to each other.  Not whether they ARE, just whether they COULD be.

You can also look at the bones themselves.  For example, you could look for cutmarks on the bone, which would definitely make the case that the stone tools are related to the bones that have… stone tool cut marks.  In one case from Washington State (USA), a bone tool was actually found embedded in another animal’s bone.  Tough to argue with that one.  But that’s rare, and sometimes, even when stone or bone tools are used, they might not leave a mark on the bone.  Sometimes, if the bone sits on the ground surface for a while before it gets buried, the bone’s outer surface can weather off, and with it the markings that would have confirmed human activity.

So what did the excavation of El Fin del Mundo show?  Although some tools were found in places that had seen disturbance, some of the tools were found mingled in among the bones.  So the context for at least some tools is good – it suggests that there’s a possible relationship.  And what about the gomphothere bones themselves?  They’re pretty weathered, so there are no markings that would confirm human interaction with the bones.  Intriguingly, there are a couple of bone fragments that appear to have some kind of artificial decoration on them.  

All in all, this isn’t a slam dunk, but then archaeology isn’t a field rife with slam dunks.  What it is, though, is a pretty strong circumstantial case, and when you’re looking at really old possible archaeological sites, mustering all your evidence and making the most well-founded interpretation you can – a strong circumstantial case – is often the best you can do.  Then you keep digging at the site, and you look for other sites, and other people find other sites, and you fill in a little more of the picture each time.  We don’t even know how much of the picture we’re missing.  And I think that’s awesome.

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About laurenwritesscience

I'm bringing scientific news and information to anyone interested, whether you're a scientist, or just love science! My focus is earth science and archaeology but I wander quite a bit.

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