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Updated: May 24, 2025
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Systematic Assessment of Mammalian Skull Specimens for Dental and Temporomandibular Joint Pathology
Published on: August 22, 2022
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Morphological variation of the Australopithecus afarensis maxilla
Hester Hanegraef1, Fred Spoor2
1Centre for Human Evolution Research, Natural History Museum, London, UK.
Journal of Human Evolution
|March 6, 2025
Summary
Australopithecus afarensis exhibits significant maxillary variation, potentially due to sexual dimorphism, differing from modern humans and apes. This study enhances understanding of early hominin diversity.
Area of Science:
- Paleoanthropology
- Primatology
- Evolutionary Biology
Background:
- Discussions on mid-Pliocene hominin diversity in East Africa often involve attributing fossils to Australopithecus afarensis or separate species.
- Understanding intraspecific variation in Australopithecus afarensis is crucial for resolving these taxonomic debates.
Purpose of the Study:
- To investigate the magnitude and pattern of maxillary morphological variation in Australopithecus afarensis.
- To compare this variation with extant hominines to better understand hominin diversity.
Main Methods:
- CT-based virtual reconstruction of nine Australopithecus afarensis maxillae from Hadar.
- Geometric morphometric analysis of 3D landmarks on 448 extant hominine maxillae (modern humans and African apes).
Main Results:
- Australopithecus afarensis displays high degrees of size and shape variation, possibly linked to sexual dimorphism.
- No significant allometry was detected despite considerable size variation.
- A potential temporal trend in maxillary size, but not shape, was observed.
- Inferred patterns of sexual dimorphism differ from those in Homo sapiens, Pan, and Gorilla.
Conclusions:
- The study provides a comprehensive understanding of maxillary variation in Australopithecus afarensis.
- Results facilitate quantitative comparisons with contemporary hominins like Kenyanthropus platyops and Australopithecus deyiremeda.
- Findings aid in evaluating variation within other Plio-Pleistocene hominins, including early Homo species.
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