<classify> Ukadaulo wa Bipedal umapezeka mmabwinja a Australopithecus kuyambira zaka 4.2-3.9 miliyoni zapitazo, ngakhale Sahelanthropus nkutheka kuti anayenda ndi miyendo iwiri koyambilira kwa zaka 7 miliyoni zapitazo.  <topic>: TransportHistory 