One of the first human traits, the small canine teeth in this male skull distinguished it from other apes. Most male primates have long canine teeth that they use to threaten and harm other males. There may have been less competition among Sahelanthropus tchadensis males, or perhaps males expressed aggression in other ways. This skull, nearly complete though flattened by distortion, is also known by its nickname, ‘Toumai,’ which means ‘hope of life’ in the local Dazaga language of Chad.