© Raffaello Pellizzon
Three has become five. Laetoli in northern Tanzania is the site of iconic ancient footprints, capturing the moment - 3.66 million years ago - when three members of
Lucy's species (Australopithecus afarensis) strode out across the landscape.
Now something quite unexpected has come to light: the footprints of two other individuals.
"Our discovery left us without words," says
Marco Cherin at the University of Perugia, Italy.
The find looks set to transform our understanding of the Laetoli site and the social dynamics of australopiths, as well as their style of walking.
The
original Laetoli footprints were discovered in 1976. Nothing quite like them had ever been found before. They remain by far
the oldest hominin footprints we know, fortuitously preserved because a group of australopiths walked across damp volcanic ash during the brief window of time before it turned from soft powder into hard rock.
"Geologists say this hardening process must have occurred in just a few hours," says Cherin.
Chance findThe new discovery came about by chance. Keen to build a museum at Laetoli to attract tourists, the authorities asked Fidelis Masao, a researcher at the University of Dar es Salaam, Tanzania, to investigate the impact that building work would have on the site's valuable geology, says Cherin. Masao and his colleagues excavated about 65 pits to get a better sense of the extent of the ash layer in which the footprints were found. One of the pits contained the new footprints - and more archaeologists, including Cherin, began to study them.
So far the researchers have uncovered 13 prints belonging to a large individual - dubbed S1 - and a single print belonging to a smaller S2 australopith. Once the whole area has been excavated, there could be as many as 50 prints belonging to S1, they say.
S1 seems to have been walking in the same direction, at the same speed - and in all probability at the same time - as the australopiths whose footprints were uncovered in the 1970s.It has been all too tempting to interpret the original trackways - often reconstructed as belonging to two adults and one juvenile - as evidence of a
prehistoric "nuclear family".
The new footprints show more adults were present, including one who was much larger, the S1 individual. That has spawned a new hypothesis about australopith social groups.
"They were probably similar in certain respects to those of our cousins, the gorillas,
with a single dominant big male accompanied by his females and their offspring," says
Giorgio Manzi at the Sapienza University of Rome, Italy, who was also involved in the excavations.
However, in other respects australopiths might have been different from gorillas. A 2011 study of isotopes in australopith teeth - which can reveal where an individual grew up - suggests it was the
smaller (probably female) australopiths that left their family groups to wander and join a new social group. This is unlike gorillas, where it's larger males that leave their family to establish a new social group.
Modern gait?The new footprints find could also help us determine if the australopiths walked like us, a controversial issue. Some researchers, like
Robin Crompton at the University of Liverpool, UK, have studied the Laetoli prints found in the 1970s. They say the depth profiles of the prints show clearly that
australopiths walked in a broadly modern way:
the hominins seem to have had a well-developed arch in the foot, and they used their big toe to push off the ground.Other researchers, including
Kevin Hatala at Chatham University in Pittsburgh, Pennsylvania, have interpreted the prints differently. Earlier this year, Hatala and his colleagues concluded that the australopith gait might have looked a little strange to modern eyes, with the
knees slightly bent as each foot struck the ground.
"A substantially long trackway could prove very informative," says Hatala.
For Cherin, one of the most exciting aspects of the new finds is the size of the S1 australopith. Its feet were 26 centimetres in length - 3.5 cm longer than the other Laetoli prints. The scientists estimate S1 might have stood 1.65 metres tall, comparable with modern humans.
However,
William Jungers at Stony Brook University School of Medicine, New York, says we should treat that figure with caution. Hominin foot bones are exceptionally rare in the fossil record, and it's
not at all clear that australopiths had feet in the same proportion to their bodies as we do. "Australopiths aren't modern people in many respects," he says.
We can expect to hear more when the researchers return to Laetoli to continue excavations, potentially as early as mid-2017.
Journal reference: eLife,
DOI: 10.7554/eLife.19568
Reader Comments
of course one can see this from the other prespective, as females don't mind sharing as much as guys do, and perhaps the women, especially if related, didn't see any need for more males? If the women could take care of themselves, then they really don't need a group of penises walking around all the time, do they? Just asking of course. Or it could be a case of supply and demand, something our current economic systems abhor as it relates to truth... so obviously...
Is this story an example of the word "assumption "
Its amazing..
So much can be explained by petrified footprints ?
What a crock.
Nothing is unknown
Science know,everything
Bawahahahahahahahaha.......
@432hz:
Don't Confuse Us say: When you see footprints in the sand, remember that the sand has shifted. And is always shifting.
Science is best at making cement.
In fact, it would like to make everything into cement.
Lest we get confused.
Or something.
ned,
out
Unless someone comes up with a different model, then they can smash it to pieces. A very persistent constant in science, ironically.
Definition of your standard scientist; a being who understands nothing, until there is nothing left to understand.
Please pardon the political incorrectness, but am I right in noting that all the posters so far, [ atomics, graeme15b, gdpetti, 432hz *, nedlud, are male), as I here proudly? ashamedly? I am?
While I am making no attempt to cause a proverbial ‘tempest in a teapot’, what does that indicate? Anything?
Why am I smiling (smirking?) as I type this?
R.C.
*Don’t take THIS wrong, either but it appears that the only poster who MIGHT be female would be 432hz and I doubt that.
RC
This highly scientific study with the isotopes and the hominins and all of that very clever siontific chatter certainly proves without any shed of doubt that our ancient ancestors (who were not at all wise and cultured to have built those pyramids and every other ancient creation that our modern brutal science is still not able to mimic with its power of destruction), well, it turns out our ancient ancestors were infact a perverted race of cultural Marxists, afterall! It's not just us!... Our ancestors were also a crooked bunch of perverts! Great science! This discovery should prove a great blow to finally destroy the family unit and bring in a totalitarian communist government.
When I saw those footprints, my first thought was : “Hey! I wonder what kind of hanky-panky those people got up to?” Science be praised! This article is truly elevating the human spirit back to that angelic realm from which we fell.
This article only further proves my indoctrinated feminist tendencies to believe that men are a bunch of brutal hooligans who clubbed women around the head from day one! Men!... It's disgraceful! You should all be ashamed of yourselves, you rightly deserve to have your testosterone drained by all of the chemicals in the foods so that you don't have any puff left in you to fight the New World Order!
Down with the Patriarchy!
Up with the Matriarchy and its army of blind Feminists who will lead this humanity into a Communist Totalitarian State!
All “joking” aside...
A few questions I'd like to ask the panel of siontists...
Why does man have one penis and woman have one vagina? Why do all the ancient stories of humanity around the world speak about the ancient One Man/One Woman root to humanity? Why does science claim that humans came from apes, but mythology implies that humans came from the stars? Does this article imply that Love is just an illusion made from our hormones? If man and woman are divided, won't they be conquered?
For me, this article is a sign of how love-less the world has become, totally backed by heartless science, and blindly followed by sott followers...
That couldn't have been a family or clan? Nope. This is the crap university teaches. Come up with an defensible idea and defend it, no matter how ridiculous.