Not everyone, however, believes A. sediba gave rise to humans.
Richard Potts, director of the Smithsonian's Human Origins Program, has pointed out that there is evidence for the genus Homo that predates A. sediba, such as an upper jawbone previously attributed to Homo habilis that dates to 2.3 million years ago.
Anthropologist Fred Grine of Stony Brook University echoed Potts' concerns.
Berger and his team, however, think that many fossils currently identified as being in the genus Homo are actually australopithecines. Churchill suggested that all fossils for Homo habilis and Homo rudolfensis might actually fall within the genus Australopithecus.
"Australopithecus sediba raises the bar on what it takes to determine if something is in the genus Homo," explained Berger, who added that many claims for early humans were just based on fragmentary evidence, such as a handful of jawbones that were dated based on surrounding fauna.
"If we only had the mandible for sediba, we would probably be calling it something else entirely, maybe Homo habilis," he said. "We learn from sediba that you need more than just one part of the anatomy, more than fragments, and that context is everything."