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Published on: February 10, 2015
Australopithecus afarensis scapular ontogeny, function, and the role of climbing in human evolution
David J Green1, Zeresenay Alemseged
1Department of Anatomy, Midwestern University, Downers Grove, IL 60515, USA. dgreen1@midwestern.edu
Science (New York, N.Y.)
|November 1, 2012
Summary
Fossil scapulae from Australopithecus afarensis suggest apelike development and significant climbing behaviors in early hominins. These findings highlight the importance of shoulder blade morphology in understanding primate locomotion.
Area of Science:
- Paleoanthropology
- Primate Anatomy
- Evolutionary Biology
Background:
- Scapular morphology is a key indicator of locomotor adaptations in primates.
- Hominin fossil scapulae are rare, limiting our understanding of early hominin shoulder anatomy and function.
- The Dikika juvenile Australopithecus afarensis skeleton provides exceptionally preserved scapulae.
Purpose of the Study:
- To analyze the scapular morphology of Australopithecus afarensis.
- To infer developmental patterns and locomotor behaviors of A. afarensis.
- To compare A. afarensis scapular traits with those of extant apes and humans.
Main Methods:
- Comparative analysis of scapular traits between juvenile and adult A. afarensis fossils.
- Comparison of fossil scapular morphology with ontogenetic data from African apes and humans.
- Functional interpretation of scapular features in relation to locomotor behavior.
Main Results:
- A. afarensis scapulae exhibit traits characteristic of suspensory apes, present in both juvenile and adult specimens.
- The stability of these traits from juvenile to adult stages suggests apelike developmental patterns.
- Specific scapular features in A. afarensis align with those associated with climbing behaviors in African apes.
Conclusions:
- Australopithecus afarensis likely possessed apelike developmental trajectories.
- The scapular evidence strongly supports a locomotor repertoire that included substantial arboreal climbing.
- Scapular morphology provides crucial insights into the functional anatomy and evolutionary history of early hominins.
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