Britannica
Sources used in this answer
- Australopithecus - Early species and Australopithecus anamensis
- human evolution - The fossil evidence
- Australopithecus - Australopithecus sediba
- Australopithecus - Australopithecus afarensis and Au. garhi
- Australopithecus - Australopithecus africanus
- human evolution - Increasing brain size
- Australopithecus
- Homo
- Australopithecus - Quality of the fossil record
How were Australopithecus species similar to modern humans?
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Australopithecus
Artist's rendering of Australopithecus afarensis, which lived from 3.8 to 2.9 million years ago.
Members of the genus Australopithecus possessed a mosaic of traits, some of which were distinctly humanlike while others remained apelike. Their primary similarity to modern humans was their ability to walk upright on two legs, known as bipedalism.12
Key humanlike features included:
- Locomotion: Anatomical evidence from the pelvis, hip, knee, and ankle of species such as Au. afarensis indicates a bipedal gait very similar to that of modern humans. Footprints found at Laetoli demonstrate an arched foot with a forward-pointing great toe and a humanlike walking pattern.13
- Dentition: While their cheek teeth were generally larger than those of modern humans, their canine teeth were reduced in size compared to those of apes.2
- Skeletal Structure: Some species exhibited humanlike curvatures in the spine. Additionally, discoveries such as Au. sediba revealed humanlike structures in the pelvis, foot, leg, and skull, including an elongated thumb that may have allowed for the use of simple tools.14
Despite these similarities, Australopithecus differed from modern humans in having significantly smaller brains and often retaining apelike traits such as curved finger and toe bones, which suggest they also engaged in arboreal climbing.312