article_snippet: The jawbone has been dated to 2.8 million years ago -- which predates the previously known fossils of the Homo lineage by approximately 400,000 years, according to Arizona State University.
article_snippet: Chalachew Seyoum, a graduate student from Ethiopia, came across the fossil -- the left side of a lower jaw with five teeth -- while on a field expedition in the Afar region of eastern Ethiopia in 2013.
article_snippet: The jawbone, found in the Ledi-Geraru area of the Afar region, combines features seen in Australopithecus afarensis with those seen in later specimens of the Homo genus, according to the study.
article_snippet: Surveying began in 2002, Reed said, but researchers only began to pick up fossils in the area where the jawbone was found in 2012, having realized the sediments there were old enough to yield Australopithecus afarensis specimens.
highlights_snippet: The jawbone was found in Ethiopia's Afar region, not far from where "Lucy" was discovered .
  
highlights_snippet: The jawbone has been dated to 2.8 million years ago, which means The jawbone helps fill in a crucial gap in our knowledge .