Ardipithecus kadabba

Ardipithecus kadabba is an early hominin species known from fragmentary fossil teeth and skeletal bones found at five localities in the Middle Awash region of Ethiopia, collected between 1997 and 2002. It lived approximately 5.77 to 5.54 million years ago, close to the time when the lineages leading to chimpanzees and humans are thought to have diverged. It is considered a probable ancestor of the later species Ardipithecus ramidus, and its teeth show a reduced canine honing complex, the wear pattern produced when canine teeth sharpen against each other, compared with living apes. This more primitive dental pattern places it among the evidence for a lineage of early hominins whose teeth grew progressively smaller over time.