Bipedal locomotion means walking on two legs in an upright position. Scientists identify whether a set of bones represents an animal who walked on two legs by examining the pelvis; bipedal locomotion is possible only with a specially adapted pelvis.
Bipedalism was first used by our hominid ancestors at least as long ago as 4.4 million years, when Ardipithecus ramidus sometimes-but not always-walked on two legs. Another of our ancestors- ramidus the Australopithecus, was a full-time bipedalist by about 2.2 million years ago. Bipedalism is one of the hallmarks of being human, despite recent mechanical inventions.
Sources
Knusel, C. J. 1992 The throwing hypothesis and hominid origins. Human Evolution 7(1):1-7.
Tobias, Phillip V. 1998 Ape-like Australopithecus after seventy years: Was it a hominid? Journal of the Royal Anthropological Institute 4(2):284-307.
This glossary entry is part of the Dictionary of Archaeology. Any mistakes are the responsibility of Kris Hirst.
