Foot Bone Suggests

Now, a fossilized foot bone from Hadar, Ethiopia, reveals that A. afarensis had arched feet, as do modern humans, and was fully committed to walking upright. The species lived between 3.7 million and 2.9 million years ago. Researchers from the University of Missouri and Arizona State University report these findings in the current issue of the journal Science. The newly found specimen is a well-preserved fourth metatarsal, one of the long bones that connects the toe to the base of the foot. The bone is more similar to the modern human foot than to that of apes, and it suggests that the A. afarensis foot had a well-formed arch that was shock-absorbing. “One little tiny bone of the foot tells us a good, long story,” said Carol V. Ward, the study’s lead author and a biologist at the University of Missouri. “They couldn’t grab on to much, and they were walking just like we were.” Until two years ago, Lucy was the earliest known skeleton from the human branch of the primate family. She was replaced by Ardi, who belongs to the species Ardipithecus ramidus and lived 4.4 million years ago. Unlike Lucy, Ardi most likely walked both upright and on all fours.