c. 4200000 BCE–c. 3800000 BCE
*Australopithecus anamensis* and knee evidence for bipedal walking
Human evolution & hominins · Australopitecos · Tibia y rodilla · Bipedismo inferido
Fossils of *Australopithecus anamensis* from eastern Africa span roughly 4.2–3.8 million years ago. A tibia about 4.1 million years old has a broad area below the knee, a trait compatible with the loads of supporting the body on one leg while walking. It is anatomical evidence for habitual bipedalism, not for uniform anatomy or ecology, nor for a demonstrated linear ancestral relationship with later species.
Precision, calendar, and review
- Start
- year · approximate
- End
- year · approximate
- Calendar and convention
- Historical-era years; the source calendar is not identified. No conversion of days is assumed.
- Year zero
- The scale goes from 1 BCE to 1 CE without year zero. Changing era names changes labels only.
- Documentary review
- Date not recorded
Reading the date: dating window; it does not mean the event lasted for that entire interval.
Sources
- humanorigins.si.edu (opens in a new tab)
Source provenance and scope
- Publication date
- Not identified in metadata; document review pending
- Source updated
- 2024-01-03
- Bibliographic date checked
- 2026-09-23
The correspondence between this reference and individual claims has not yet been itemized.
This record is an editorial synthesis. Consult the sources to check claims and their limits. Chronological relationships alone do not establish causation.