New Hominid Fossils Discovered

[Avatar]

Naledi Fossil Find

Johannesburg - Scientists have announced the discovery of a new species of human relative in a remote cave chamber in the Cradle of Humankind World Heritage Site.

The discovery of the fossils - representing at least 15 individuals - may alter views of human behaviour, it was announced on Thursday by Wits University, the National Geographic Society and the South African Department of Science and Technology/ National Research Foundation (DST/NRF).

Besides shedding light on the origins and diversity of our genus, the new species, Homo naledi, appears to have intentionally deposited bodies of its dead in a remote cave chamber, a behaviour previously thought limited to humans.

The findings are described in two papers published in the scientific journal eLife and reported in the cover story of the October issue of National Geographic magazine (natgeo.org/naledi) and a NOVA/National Geographic Special (#NalediFossils).

An international team of scientists took part in the research.

Consisting of more than 1 550 numbered fossil elements, the discovery is the single largest fossil hominin find yet made on the continent of Africa.

The initial discovery was made in 2013 in a cave known as Rising Star in the Cradle of Humankind World Heritage Site, about 50km northwest of Johannesburg, by Wits University scientists and volunteer cavers.

The fossils, which have yet to be dated, lay in a chamber about 90 metres from the cave entrance, accessible only through a chute so narrow that a special team of very slender individuals was needed to retrieve them.

So far, the team has recovered parts of at least 15 individuals of the same species, a small fraction of the fossils believed to remain in the chamber.

“With almost every bone in the body represented multiple times, Homo naledi is already practically the best-known fossil member of our lineage,” said Lee Berger, research professor in the Evolutionary Studies Institute at the University of the Witwatersrand and a National Geographic Explorer-in-Residence, who led the two expeditions that discovered and recovered the fossils.

“This is a tremendously significant find,” said Terry Garcia, the National Geographic Society’s chief science and exploration officer. “That is why, when National Geographic received a call from Lee Berger reporting the fossils’ initial discovery, we immediately committed our support to this remarkable effort.”

A blend of primitive and human

H. naledi was named after the Rising Star cave — “naledi” means “star” in Sesotho.

“Overall, Homo naledi looks like one of the most primitive members of our genus, but it also has some surprisingly human-like features, enough to warrant placing it in the genus Homo,” said John Hawks of the University of Wisconsin-Madison, a senior author on the paper describing the new species. “H. naledi had a tiny brain, about the size of an average orange (about 500 cubic centimetres), perched atop a very slender body.”

The research shows that on average H. naledi stood approximately 1.5 metres tall and weighed about 45kg.

H. naledi’s teeth are described as similar to those of the earliest-known members of our genus, such as Homo habilis, as are most features of the skull. The shoulders, however, are more similar to those of apes.

“The hands suggest tool-using capabilities,” said Dr Tracy Kivell of the University of Kent in the UK, who was part of the team that studied this aspect of H. naledi’s anatomy. “Surprisingly, H. naledi has extremely curved fingers, more curved than almost any other species of early hominin, which clearly demonstrates climbing capabilities.”

This contrasts with the feet of H. naledi, which are “virtually indistinguishable from those of modern humans,” said Dr William Harcourt-Smith of Lehman College, City University of New York, and the American Museum of Natural History, who led the study of H. naledi’s feet.

Its feet, combined with its long legs, suggest that the species was well-suited for long-distance walking.

“The combination of anatomical features in H. naledi distinguishes it from any previously known species,” added Berger.

Appearance of ritualised behaviour

Perhaps most remarkably, the context of the find has led the researchers to conclude that this primitive-looking hominin may have practiced a form of behaviour previously thought to be unique to humans.

The fossils - which consist of infants, children, adults and elderly individuals - were found in a room deep underground that the team named the Dinaledi Chamber, or “Chamber of Stars”.

That room has “always been isolated from other chambers and never been open directly to the surface,” said Dr Paul Dirks of James Cook University in Queensland, Australia, lead author of the eLife paper on the context of the find. “What’s important for people to understand is that the remains were found practically alone in this remote chamber in the absence of any other major fossil animals.”

So remote was the space that out of more than 1 550 fossil elements recovered, only about a dozen are not hominin, and these few pieces are isolated mouse and bird remains, meaning that the chamber attracted few accidental visitors.

“Such a situation is unprecedented in the fossil hominin record,” Hawks said.

The team notes that the bones bear no marks of scavengers or carnivores or any other signs that non-hominin agents or natural processes, such as moving water, carried these individuals into the chamber.

“We explored every alternative scenario, including mass death, an unknown carnivore, water transport from another location, or accidental death in a death trap, among others,” said Berger.

“In examining every other option, we were left with intentional body disposal by Homo naledi as the most plausible scenario.”

This suggests the possibility of a form of ritualised behaviour previously thought to be unique to humans. (In this context, “ritualised” refers to repeated behaviour.)

“Underground astronauts”

The fossil material was recovered in two expeditions conducted in November 2013 and March 2014, dubbed the Rising Star Expeditions. In the initial expedition, over a period of 21 days, more than 60 cavers and scientists worked together in what Marina Elliott, one of the excavating scientists, described as “some of the most difficult and dangerous conditions ever encountered in the search for human origins”.

Elliott was one of six women selected as “underground astronauts” from a global pool of candidates after Berger issued a call on social media for experienced scientist/cavers who could fit through the 18-centimetre-wide cave opening.

Social media continued to play a role in the project, as the team shared expedition progress with a large public audience, schoolchildren and scientists.

“This was a first in the history of the field,” said Hawks, who worked with Berger to design the media outreach.

The fossils were analysed in a unique workshop in May 2014 funded by the South African DST/NRF, Wits University and National Geographic.

More than 50 experienced scientists and early-career researchers came together to study and analyse the treasure trove of fossils and to compose scientific papers.

Much remains to be discovered in the Rising Star cave. “This chamber has not given up all of its secrets,” Berger said.

“There are potentially hundreds if not thousands of remains of H. naledi still down there.”

“If we learned about a completely new form of hominin only because a couple of cavers were skinny enough to fit through a crack in a well-explored South African cave, we really don’t have a clue what else might be out there,” National Geographic Executive Editor for Science Jamie Shreeve writes in National Geographic magazine.

--A

[sgt.null]

all Satan's lies.

[wayfriend]

There's a nice piece in CNN.com about it here. In that it has some good pics.

In this pic, he looks like a man who just found out he can't watch the game tonite because his wife is taking him to the book club.

[Hashi Lebwohl]

Fascinating stuff. 1.5m and 45kg? So...shorter-than-average elves...or an average peasant from the Middle Ages....or a modern 14-year-old-girl with a slender build.

What would really make this story great would be to find some item of sufficient technological development to throw all our ideas of our ancient ancestors out of balance. Anything tooled, whether by hand or as if by primitive grinding on a whetstone, anything mechanical, or anything with writing on it.

[Wosbald]

+JMJ+

In this pic, he looks like a man who just found out he can't watch the game tonite because his wife is taking him to the book club.

I thought he looked like Andy Serkis as Caesar.

[Avatar]

Nice pics, thanks WF. I see there are already people disputing that it was a burial site, and that they deserve to be classified as a new/separate species. The joy of science.

--A

[wayfriend]

I think things are a bit held up due to not having determined the age of the fossils. Without that, they don't really know which Bunch and Beam of the Evolloo H. naledi belongs to.

[Avatar]

Agreed.

--A

[peter]

I read that the H. erectus team were claiming him as (possibly) one of theirs. Thing is much of the kudos in palaeoanthropology comes from discovering a new link in the chain rather than another example of an existing one - and it has to be a direct descendant! To discover a member of a line that leads to a dead end is to be an also ran. That branch of science is rife with professional jealousy: read the account of the rivalry between Johannsenn and the Leakey's (in Lucy I think) as an the example. Clear evidence that this one is on our own line can however be implied from the superb adaptation of huge nostrils ideally suited for snorting prodigious quantities of coke. I thus rename him H. rockstarius forthwith.

[peter]

Saw a documentary on this find last night and it certainly represents the most perplexing of paleoanthropological finds - possibly ever! The sheer bulk of fossil remains; the absolute absence of any intermingled animal fossils; the almost unavoidable conclusion that these remains were 'placed' [nearly 2 million years before any such 'burial' style activity had been seen before] - all of these things demand an almost complete revision of our understanding of the development of modern man from his great ape forebears.

The scientists seem happy that the finds sit within the Homo genus [ie man] rather than in the Australopithicene group [still definitely ape although bi-pedal]. This is based on skull fragments from the ocipital region and on jaw/teeeth shape and size. The dating places the finds at approx 1.9 million y.o. - right on the cusp of the appearence of the Homo genus, and thus has the hackneyed phrase 'missing-link' been applied to this discovery.

It's a very bizzare find and one hates to be the one playing 'devils advocate', but in such circumstances it is probably best to give at least a passing thought to the adage "If something seems to good to be true, then it probably is". I do not say this in any way to suggest any kind of irregularity on the part of the scientists involved in the find, but it would not be the first time that the advance of this very challenging discipline has been derailed [for decades in fact] by a hoax enacted by individuals other than the reputable discoverers of the find. There is so much at stake in the establishment of this find as genuine, so much revision of our previous painfully gained knowledge that the possibility of error has to be considered and eliminated. This find, if validated will demand no less than the complete rethinking of human history from day one. As an example, the development of ceremonial style activity ten times earlier, and in brains of much smaller size than previously encountered, will demand a complete overhaul of ares such as cognitive development in relation to brain size etc - so if we get it wrong the ramifications throughout many interconnected disciplines will be catastrophic. Careers will be made and broken on the back of this discovery, not to mention that it will either advance or impede our search for the truth of our ancestry by factors of decades. We have to be sure. We have to get it right.

[Avatar]

Agree on the importance of validating it. Seems an unlikely candidate for a hoax though...some sort of mistake is more likely than that.

--A

[peter]

Yes absolutely. There are many more ways this could be a steer in a wrong direction than by deliberate fraud.