delinquent noun [C]. âº a âperson, usually âyoung, who âbehaves in a way that is âillegal or not âacceptable to most âpeople: âjuvenile delinquents.
Sahelanthropus may have walked on two legs. The oldest evidence for walking on two legs comes from one of the earliest humans known, Sahelanthropus. Walking upright may have helped this species survive in the diverse habitats near where it livedâincluding forests and grasslands.
Adam (if you are religious and believe in it)   or:   (if you follow the timelines of the earth and respect the hard working anthropologists) Homo erectus was the firstâ¦ to walk upright. B. Use tools.   While this is still a point of contention among researchers, there are a few leading theories.