Peter Schmid and William Harcourt-Smith / Wits University
Peter Schmid and William Harcourt-Smith / Wits University

Homo Naledi's Bones Were Made For Walking … and Climbing

Peter Schmid and William Harcourt-Smith / Wits University
Peter Schmid and William Harcourt-Smith / Wits University

Its bones were made for walking—and for climbing, and possibly for tool making. That’s the latest insight to emerge from the ongoing analysis of Homo Naledi, our newest human relative, discovered in 2013 in the deep, nearly inaccessible Rising Star cave system in South Africa’s Cradle of Humankind. A pair of papers recently published in Nature Communications—one on the creature’s foot, and the other on the hand—paint a more detailed picture of these small-brained creatures.  

In the foot study, a team of researchers led by William Harcourt-Smith, a paleoanthropologist at Lehman College and a resident research assistant at the American Museum of Natural History, analyzed 107 bones from the foot of H. Naledi, including one nearly complete adult foot.

“The key finding is that this is a foot that is really, really human-like in most respects,” Harcourt-Smith told mental_floss. “However, in such a human-like foot, we did also find a couple of features that aren’t so human-like.”

He points to the creature’s slightly curved bones in its toes—a more primitive feature that may have been used to climb trees. It also seems to have had an arch that was quite low, which may have affected how it could have walked long distances on two legs, Harcourt-Smith says: “That in itself is quite interesting, because it points to how these animals were experimenting with walking upright. And, of course, bipedalism defines us as being human.”

A digital reconstruction of the H. Naledi foot. (a) Dorsal view. (b) Distal view of the cuneiforms and cuboid showing transverse arch reconstruction. (c) Medial view showing the moderate longitudinal arch. Image credit: Harcourt-Smith et al. in Nature Communications

In the hand study, a team lead by paleoanthropologist Tracy Kivell, of the University of Kent’s Skeletal Biology Research Centre, studied the near-complete hand (it’s missing one wrist bone known as a pisiform) of H. Naledi that was found with the bones still partially connected—an extraordinarily rare find. Some 150 hand bones were unearthed in the cave in all.

The 26 bones show a mix of characteristics that have never been seen before in any other hominin species, they say. The wrist bones have adaptive features that would’ve helped H. Naledi use tools (though none have been discovered) that are consistently found only in modern humans and Neanderthals. On the other hand, the finger bones are curved more than most australopiths—bipedal hominids like the 3.3-million-year-old Lucy—and very different from the straight fingers of humans and Neanderthals, which indicates the creature spent a good amount of time climbing.

The H. Naledi bones have yet to be dated, which means we don't know where they fit in among our hominid relatives. "Depending on how old (geologically) the H. naledi remains turn out to be, there will be important implications for interpreting the South African archaeological record, who made the various stone tools that have been found, and what anatomical adaptations were necessary to craft these implements," Kivell said in a statement sent to mental_floss.  

The hand of H. Naledi. (a) Palmar (left) and dorsal (right) views of the right hand bones, (b) found in situ in semi-articulation with the palm up and fingers flexed. The palmar surface of the metacarpals (Mc) and dorsal surface of the intermediate phalanges (IP) can be seen. Image credit: Kivell et al. in Nature Communications

When you put together the mostly modern foot and the modern-primitive hand with other features of the H. naledi body—especially the shoulder suited for climbing and a tiny skull that is decidedly un-human like in size—you get a picture of a creature that is utterly unlike anything else in the fossil record, Harcourt-Smith says. H. Naledi’s unique suite of characteristics “really speak to a unique experiment with being upright, with some part of the time spent being in the trees and some of the time walking around on the ground,” he says.

They’re not yet sure how the creature would have walked. “We haven’t come up with a really good model how it moved yet,” Harcourt-Smith says. “It’s a real conundrum. But I can tell you this: It would’ve spending most of its time walking upright. Its heel would’ve struck the ground the way ours does, and when it was walking it would’ve [looked] distinct from us—but not that much so.”

He continues, “What’s really interesting is that we always used to think with the genus Homo that one of the hallmarks of it was being a full upright, sort of obligate, 100 percent biped. But we now have a creature that we’ve assigned to Homo based on its feet and skull, and yet it’s not really walking upright 100 percent of the time. It raises as many questions as it answers about bipeds.”

Figuring out how H. naledi moved is one of the next big areas of inquiry for the foot researchers. “We really want to reconstruct the gait of this creature,” Harcourt-Smith says. “That means working with all of the teams and coming up with a really robust biomechanical evaluation of the whole. It’ll be a few years worth of work.”

They're also going to investigate the internal architecture, he says. “We’re going to be looking at the molecular structure, and that requires very high-resolution CT scanning.”

As for the hand, Kivell too will be peering inside. “We have done microCT scans of the hand bones and will next analyze the internal bony structure—trabecular and cortical bone—which can tell us more information about function and how the H. naledi hand was used,” she told mental_floss in an email.     

While the science continues, the scientists themselves seem to still be riding the high of the discovery of this unprecedentedly large assemblage of unique bones, and excited by what they can teach us about our evolutionary past.

“When I got down there, it was fossil heaven,” Harcourt-Smith says. “There were so many different things. You never get these sort of opportunities with this amount of stuff found so quickly, and it really was an extraordinary privilege to work on. It’s not normal to get this sort of treasure trove of material in one go. It’s new territory in some ways.”

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Romano D’Agostini, Giorgio Cargnel, Soprintendenza Speciale di Roma
Utility Workers May Have Found One of Rome’s First Churches
Romano D’Agostini, Giorgio Cargnel, Soprintendenza Speciale di Roma
Romano D’Agostini, Giorgio Cargnel, Soprintendenza Speciale di Roma

The remains of what may have been one of Rome’s earliest Christian churches were accidentally discovered along the Tiber River during construction, The Local reports. The four-room structure, which could have been built as early as the 1st century CE, was unearthed by electrical technicians who were laying cables along the Ponte Milvio.

The newly discovered structure next to the river
Romano D’Agostini, Giorgio Cargnel, Soprintendenza Speciale di Roma

No one is sure what to make of this “archaeological enigma shrouded in mystery,” in the words of Rome’s Archaeological Superintendency. Although there’s no definitive theory as of yet, experts have a few ideas.

The use of colorful African marble for the floors and walls has led archaeologists to believe that the building probably served a prestigious—or perhaps holy—function as the villa of a noble family or as a Christian place of worship. Its proximity to an early cemetery spawned the latter theory, since it's common for churches to have mausoleums attached to them. Several tombs were found in that cemetery, including one containing the intact skeleton of a Roman man.

Marble flooring
Romano D’Agostini, Giorgio Cargnel, Soprintendenza Speciale di Roma

A tomb
Romano D’Agostini, Giorgio Cargnel, Soprintendenza Speciale di Roma1

The walls are made of brick, and the red, green, and beige marble had been imported from Sparta (Greece), Egypt, and present-day Tunisia, The Telegraph reports.

As The Local points out, it’s not all that unusual in Rome for archaeological discoveries to be made by unsuspecting people going about their day. Rome’s oldest aqueduct was found by Metro workers, and an ancient bath house and tombs were found during construction on a new church.

[h/t The Local]

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Alexis Pantos, University of Copenhagen
Scientists Just Found the Oldest Known Piece of Bread
Alexis Pantos, University of Copenhagen
Alexis Pantos, University of Copenhagen

An old, charred piece of long-forgotten flatbread has captured the interest of archaeologists, anthropologists, and historians around the world. Found in a stone fireplace in Jordan’s Black Desert, this proto-pita dates back 14,400 years, making it the oldest known example of bread, Reuters reports.

To put the significance of this discovery in context: the flatbread predates the advent of agriculture by 4000 years, leading researchers to theorize that the laborious process of making the bread from wild cereals may have inspired early hunter-gatherers to cultivate grain and save themselves a whole lot of trouble.

“We now have to assess whether there was a relationship between bread production and the origins of agriculture,” Amaia Arranz-Otaegui, a researcher with the University of Copenhagen, told Reuters. “It is possible that bread may have provided an incentive for people to take up plant cultivation and farming, if it became a desirable or much-sought-after food.”

A report on these findings—written by researchers from the University of Copenhagen, University College London, and University of Cambridge—was published in the journal Proceedings of the National Academy of Sciences.

It was once thought that bread was an invention of early farming civilizations. A 9100-year-old piece of bread from Turkey was previously regarded as the oldest of its kind. However, the Jordanian flatbread was made by a group of hunter-gatherers called the Natufians, who lived during a transitional period from nomadic to sedentary ways of life, at which time diets also started to change.

Similar to a pita, this unleavened bread was made from wild cereals akin to barley, einkorn, and oats. These were “ground, sieved, and kneaded prior to cooking,” according to a statement from the University of Copenhagen. The ancient recipe also called for tubers from an aquatic plant, which Arranz-Otaegui described as tasting “gritty and salty."

[h/t Reuters]

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