Brian Handwerk
for National Geographic News

December 1, 2005
In July a team of English researchers reported the discovery of human footprints in Mexico that appeared to be 30,000 years older than when most scientists believe humans arrived in the Americas.

Researchers commonly accept that humans came to the Americas some 11,500 years ago. But new dating of the Mexican find suggests that the features are in fact 1.3 million years old.


If the new dates are correct, the footprints could be among the most incredible hominid traces ever discovered—or, more likely, not footprints at all.

"One-point-three million years is a lot older than I expected," said Paul Renne, director of the Berkeley Geochronology Center at University of California, Berkeley.

"I repeated the experiment nine times using different samples, usually single chunks of this basaltic rock, and they all gave the same unambiguous results."

Silvia Gonzalez, a geoarchaeologist at England's Liverpool John Moores University, and a team of colleagues first discovered the features in 2003. The researchers found them embedded in basaltic lava on the floor of an abandoned quarry near Puebla in central Mexico.

The team identified the indentations as footprints and dated them at 40,000 years old.

But if Renne's new dates are correct, the prints may be those of an incredibly ancient hominid, made well over a million years before the Americas are believed to have been inhabited.

Or they may simply be indentations in the rock.

Renne reports his new dating results in this week's Nature.

The First American?

Renne visited the site in June 2004 and noted that it shows the effects of many impacts over time.

"My conclusion is that this is a deeply disturbed surface," he said. "It's been walked on, driven on, walked on by animals. Sleds carrying building stones have been driven over it.

"It has a lot of indentations, and some of them are what has been interpreted as footprints. We found a huge variety of those of different shapes and depths."


In addition to the 1.3-million-year date, Renne's rock samples also revealed reverse magnetic polarity. The Earth's magnetic field reversed its polarity 790,000 years ago, Renne explained, so the rocks must be older than that.

He says he thinks it's very unlikely that the indentations are footprints but that he was keeping an open mind.

"We can't definitely rule out that these are footprints," he said. "I'm a geologist and not an anthropologist. But if that's true, it would be one of the most remarkable discoveries in centuries."

Gonzalez, of the English research team, responded to Renne's report with a written commentary released to the media.

She stressed that the layer of ash in which the features lie has been difficult to date, because it consists of many different materials that may be of different ages.

Her group used lasers to measure radiation in particles of the ash layer and dated them as being about 40,000 years old.

"[Those dates] now need to be explained in view of the new dates obtained by Renne's group," she wrote.

Gonzalez believes that the new dates spotlight the need for further research on the site by other techniques and by independent groups to establish a reliable timeline.

But even if Renne's ancient dates are correct, Gonzalez says, she isn't ready to rule out the possibility that the features could be footprints.

"Even if we are wrong and the … ash is indeed 1.3 million years old, as suggested by Renne et al., that is not automatically a reason to disregard interpretation of the features reported as 'footprints' simply because they are not in agreement with the established models for the settlement of the Americas," she wrote.

WOW!
And they actually admit to prejudice in their field.

I think it's more of a case of 'lets get as much publicity as possible so that we can get extra funding to keep going'

never looked at it like that and it makes since, alittle controversy and things get money.
Still its one heck of a find.

If they are footprints!

got a feeling they are

Let's wait & see.

Probably Vikings.....

Just kidding. I would agree with the money theory for now.Seems like an awful long time ago....

Liked the Viking idea, or maybe it was the cast of Lost ....no they're in Hawaii fighting giant Polar Bears! What is that all about anyway? We're still getting season 1, and still trying to work it all out.
We reckon on they're all dead, and in a holding area until they work out whether they go to heaven or hell
>>?

I can't help with the cast of lost thingy, over too you Sir Steve

Sorry guys, never seen the show, but from I hear, it's a cult following. All I know is that they film it here in a secret location and its all hush-hush. There was a recent article about it where they got some quotes from a couple grips or something, which put the spotlight on the newspaper getting too close.

It reminds me a little of "Twin Peaks". Remember that one? It was this show about this town in Colorado, I think up in the mountains, sort of secluded and there was this murder. Then during thelocal investigation, you are introduced to the characters of the town and the viewer is supposed to look for clues. The problem with the show, like this one, is that the clues are very ambiguous and sent everyone on a wild goose chase until nobody knew what the hell was really going on anymore, but KEEP WATCHING! IT'S GONNA BE IN THE VERY NEXT EPISODE.....

I was working downtown one day at the YWCA and they had it all mocked up like a psychiatrists' office for an episode of Lost. Didn't know then....don't know now.

It's a strange one,and a lot of people are hooked trying to work out what it's all about, a bit religious, a bit supernatural, a bit 'Carrie', and why are there polar bears in the sub-tropics? It's all about a plane that crashed 3000 miles off course. The island they're on seems to act a a magnet for disaster, plane crashes, ship wrecks etc. Wouldn't say I'm hooked, but I'd be disappointed if I missed one.

Polar bears? Are you kidding me? What's next....aliens?

Funny thing, I grabbed a paper today from a depressing looking guy selling them in the traffic line (out of sympathy, really) and on the front page was an article exlaining that two of the main actresses have been arrested for DUI a second time and had mug shots on the front page. I think they said they were lost.....

Aye, polar bears, well one very big one to be exact, and it eats people. They killed a big one, it's pup, in an early episode. Strange series, but they will keep everyone guessing what it's all about until it gets pulled. As soon as they tell you it will be over, but it would have to be something extraordinary to make sense of it all. I doubt there will ever be an explanation.
My sympathy over the karaoke, , sorry you said not to laugh. I can't sing , but it beats me why folks who can't sing get up in front of everyone to make an a@@ of themselves, I suppose it makes you appreciate the ones who can sing all the more. It could be really useful for bar owners, put a really bad singer on repeatedly when you need to empty the place!

Aye.....it would work, too! But then there were really bad singers last night....

As to Lost, I think the title says it all....they were talking about the viewers.

Lost viewers, could go that way over here too, just had episode 19 of season 1, and although there is a clue as to what 'The Island 'is all about each episode, it just seems to make less sense each time.
Cult following =small and but enthusiastic audience, =entertainment speak for not the success we expected.

Isn't this the show Hollywood was saying was going to be a real life version of Gilligan's Island?
wait...some how thats just all wrong....
Gilligan's island and real life in one sentence.

Now now Skipper, not so hasty...... or maybe there's a point there.
Lost and real life, as much similarity as Life & Gilligan's Island.
Lost and Gilligan's island, only similarity in truth are the coconuts!
BTW, Cleave's point about two girls from the cast being caught driving under the influence has made the news on teletext over here!
Problem is they've given a good part of a future story line away in doing so, both girls are from season 2, so now anyone who didn't know, knows that the other half of the plane has survivors we haven't seen yet!

I'm confused....plane crash with suvivors who are lost...how lost when they are picked up for DUI?
Yup its the island with out doubt its the coconuts fault I'm sure.

C'mon LOST?! If you want a good cult following, that would be Stargate SG-1! I was a die hard fan on that one till they took out Sam and Jack though. Now waiting to see what might come of next season.

Maybe it'll end up like Lord of the Flies..you know, two camps of survivors on the same island sort of thing. I'm curious....do they eat food?

Coconuts and wild boar (when they can catch it), so maybe a bit of Lord of the Flies!

Do they have a Piggy?

They killed and ate a few in the first couple of episodes, but piggy took on a more spiritual role in a later episode, convincing at least one character that he might be a re-incarnation of a man he killed by mistake before catching the flight.
Shades of Twilight Zone there (he says with the theme playing in the background creating an eerie sense of wonder!).
You know the more I write about this, the less appealing and more ridiculous the next episode sounds, maybe I should go back to watching re-runs of Time Team, the archaeology programme. Love this wee guy
Brilliant.