1. Which of the following is an adaptive characteristic of bipedalism? A. absence of arch in the foot B. nails instead of claws C. convergent eyes D. valgus knee 2. The earliest pre-australopithecine found outside the East African Rift Valley is A. Orrorin tugenensis. B. Ardipithecus kadabba. C. Sahelanthropus tchadensis. D. Ardipithecus ramidus. 3. Which of the following is a derived trait of Sahelanthropus tchadensis? A. big toe opposability B. length of the calcaneus C. larger body size D. nonhoning chewing