This is a reconstruction of Homo naledi built following 700 hours of work by paleoartist John Gurche.

On Thursday September 10, 2015 a group of scientists excavating a cave system in South Africa released their findings claiming that they may have made an important discovery about human evolution.  In late 2013 and early 2014 the scientists discovered fifteen nearly-complete skeletons in a nearly-inaccessible chamber, now called the Dinaledi Chamber, and are now classifying them as a new species of hominin called the Homo naledi.  The species warranted classification in the homo genus because of surprising human-like features, such as teeth and skull features similar to other members of the genus, and hand shapes that suggested tool-using capabilities.  It also appears to be one of the genus’s most primitive members because it possesses a much smaller brain, shoulders shaped like those of apes, and extremely curved fingers demonstrating climbing capabilities.

The most significant finding of the expedition was that Homo naledi may have practiced a form of behavior previously thought to be unique only to humans.  The isolation of the chamber and presence of few other animal bones led the team of scientists to believe that the bodies had been intentionally left there, perhaps as a burial ritual.  The deposition of bodies in the same location is generally a cultural practice, and it appears that burials were repeatedly carried out in that specific location over the course of many years.  The location was so incredibly isolated that when the team first discovered the chamber, bones lied directly on the surface, as they had not been affected by erosion, scavengers, or other climate conditions.

This is a map of the archaeological site, showing the complexity of the cave system and location of the fossil site.

The isolation of the archaeological site posed significant challenges for the team of researchers.  The first expedition lasted 21 days during November 2013 and consisted of tedious extraction of the bones by carefully using toothpicks and brushes to gently remove the fossils and transport them up to the surface through a 7.5-inch chute.  Sixty cavers and scientists were working on the excavation site, which also trained six women to be “underground astronauts” to fit through the narrow 18-centimeter cave opening.  The depth of the cave made full excavation impractical, so the scientists were forced to finish removing the bones during a week-long expedition in early 2014.

Exploration of human origins has made significant strides as more remains of ancestors are being found.  However there had been a million-year-long gap in the fossil record in which lies the beginning of mankind.  The origin of the homo genus has been shrouded in mystery, but this discovery may help to fill in the pieces of the puzzle and uncover the true origin of mankind.

Sources:

http://popular-archaeology.com/issue/fall-2015/article/scientists-discover-new-early-human-species (images are also from this site)

http://www.bbc.com/news/science-environment-34192447

Further Reading:

http://www.sciencedaily.com/releases/2015/09/150910084610.htm

http://elifesciences.org/content/4/e09560 (detailed published study report)

The NOVA/National Geographic Special, “Dawn of Humanity,” premieres September 16, 2015, at 9 p.m. ET/8 p.m. CT on PBS in the United States and is streaming online now at: http://www.pbs.org/wgbh/nova/evolution/dawn-of-humanity.html