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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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Stones, Bones, and Wrecks
Buckingham Palace Was Built With Jurassic Fossils, Scientists Find
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The UK's Buckingham Palace is a vestige from another era, and not just because it was built in the early 18th century. According to a new study, the limestone used to construct it is filled with the fossilized remains of microbes from the Jurassic period of 200 million years ago, as The Telegraph reports.

The palace is made of oolitic limestone, which consists of individual balls of carbonate sediment called ooids. The material is strong but lightweight, and is found worldwide. Jurassic oolite has been used to construct numerous famous buildings, from those in the British city of Bath to the Empire State Building and the Pentagon.

A new study from Australian National University published in Scientific Reports found that the spherical ooids in Buckingham Palace's walls are made up of layers and layers of mineralized microbes. Inspired by a mathematical model from the 1970s for predicting the growth of brain tumors, the researchers created a model that explains how ooids are created and predicts the factors that limit their ultimate size.

A hand holding a chunk of oolite limestone
Australian National University

They found that the mineralization of the microbes forms the central core of the ooid, and the layers of sediment that gather around that core feed those microbes until the nutrients can no longer reach the core from the outermost layer.

This contrasts with previous research on how ooids form, which hypothesized that they are the result of sediment gathered from rolling on the ocean floor. It also reshapes how we think about the buildings made out of oolitic limestone from this period. Next time you look up at the Empire State Building or Buckingham Palace, thank the ancient microbes.

[h/t The Telegraph]

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©Thomas Jefferson Foundation at Monticello
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Stones, Bones, and Wrecks
Inside the Kitchen of Thomas Jefferson's Acclaimed—and Enslaved—Chef James Hemings
 ©Thomas Jefferson Foundation at Monticello
©Thomas Jefferson Foundation at Monticello

James Hemings once prepared lavish dishes for America's founding fathers at Monticello, Thomas Jefferson's Virginia plantation. Though enslaved, he trained in France to become one of colonial America's most accomplished chefs. Now, archaeologists have uncovered the kitchen where Hemings created his elaborate banquets, LiveScience reports.

Researchers at Monticello are conducting a long-term effort, the Mountaintop Project, to restore plantation premises, including slave quarters, to their original appearance. Archaeologists excavated a previously filled-in cellar in the main house's South Pavilion, where they found artifacts like bones, toothbrushes, beads, and shards of glass and ceramics. Underneath layers of dirt, experts also uncovered the kitchen's original brick floor, remnants of a fireplace, and the foundations of four waist-high stew stoves.

"Stew stoves are the historic equivalent of a modern-day stovetop or cooking range," archaeological field researcher manager Crystal Ptacek explains in an online video chronicling the find. Each contained a small hole for hot coals; centuries later, the cellar floor still contains remains of ash and charcoal from blazing fires. Hemings himself would have toiled over these stoves.

During the colonial period, wealthy families had their slaves prepare large, labor-intensive meals. These multi-course feasts required stew stoves for boiling, roasting, and frying. Archaeologists think that Jefferson might have upgraded his kitchen after returning from Paris: Stew stoves were a rarity in North America, but de rigueur for making haute French cuisine.

Hemings traveled with Jefferson to France in the 1780s, where for five years he was trained in the French culinary arts. There, Hemings realized he was technically a free man. He met free black people and also learned he could sue for his freedom under French law, according to NPR.

And yet he returned to the U.S. to cook for Jefferson's family and guests, perhaps because he didn't want to be separated from his family members at Monticello, including his sister, Sally. He later negotiated his freedom from Jefferson and trained his brother Peter as his replacement. Hemings ended up cooking for a tavern keeper in Baltimore, and in 1801, shortly after turning down an offer from now-president Jefferson to be his personal chef, he died by suicide.

"We're thinking that James Hemings must have had ideals and aspirations about his life that could not be realized in his time and place," Susan Stein, senior curator at Monticello, told NPR in 2015. "And those factors probably contributed to his unhappiness and his depression, and ultimately to his death."

Hemings contributed to early America's culinary landscape through dessert recipes like snow eggs and by introducing colonial diners to macaroni and cheese, among other dishes. He also assisted today's historians by completing a 1796 inventory of Monticello's kitchen supplies—and he's probably left further clues in the estate's newly uncovered kitchen, says Gayle Jessup White, Monticello's community engagement officer—and one of James's relatives.

"My great-great-great-grandfather Peter Hemings learned to cook French cuisine from his brother James on this stove," White tells Mental Floss. "It was a spiritual moment for me to walk into the uncovered remains of Monticello's first kitchen, where my ancestors spent much of their lives. This discovery breathes life into the people who lived, worked and died at Monticello, and I hope people connect with their stories."

[h/t Live Science]

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