The remains of what could be a new species of ancient human were discovered in South Africa, according to two studies published in the journal eLife.
Currently, Homo sapiens (or modern humans) are the only living species in the genus Homo. But 100,000 years ago, other species belonging to the same genus were still alive. Modern humans, extinct species under Homo, and the immediate ancestors of Homo sapiens and their close relatives all fall under the label ‘hominin.’
The researchers who discovered the bones have dubbed the species Homo naledi. The bones were found in the Dinaledi Chamber of the Rising Star cave system. (http://elifesciences.org/content/4/e09560) ‘Naledi’ means ‘star’ in the Sotho or Sesotho language, a South African language. Around 1,550 fossil specimens from 15 individuals were found. (http://elifesciences.org/content/4/e09561) More bones are still in the chamber as well.
However, other experts say that it’s too soon to claim that H. naledi is a new species of hominin, arguing that the bones are similar to those of Homo erectus.
“The few ‘unique’ features that potentially define the new species need further scrutiny, as they may represent individual variation, or variation at the population level,” said Christoph Zollikofer, an anthropologist from the University of Zurich.
According to the researchers, H. naledi was around the same size and weight as a small modern human and had humanlike hands and feet. The males were around 5 feet tall, with slightly shorter females. Its brain was the size of a gorilla’s and its ribcage, shoulder, and pelvis resembled early hominin species.
One interesting thing about H. naledi’s discovery is that a large number of fossils were found close together in a chamber deep inside a cave system. The entrance to the chute that leads to the chamber is only 8 inches wide. No other large animal remains were found in the chamber, and the fossils hadn’t been damaged by scavengers or predators.
One possible explanation the researchers are looking into is that bodies were placed there in a sort of burial ritual, though they’re not ruling out other explanation.
“However, a number of other explanations cannot be completely ruled out and further investigation is now needed to uncover the series of events that resulted in this unique collection of hominin fossils,” one of the studies said.
Another challenge the researchers have to address is the dating of the remains to see how old they are. Since the bones weren’t encased in rock, the scientists have been unable, so far, to date the remains.