A late Miocene hominid partial pelvis from Hungary

Area of Science:

• Paleoanthropology
• Primate Anatomy
• Evolutionary Biology

Background:

• Hominoid pelvis evolution is key to understanding hominoid adaptations.
• Fossil evidence is scarce, limiting our understanding of early hominoid pelvic morphology.
• Rudapithecus hungaricus offers new insights into Miocene ape pelvic structure.

Purpose of the Study:

• To analyze the pelvic morphology of Rudapithecus hungaricus.
• To compare Rudapithecus with extant and fossil anthropoids.
• To infer the evolutionary trajectory of the hominoid pelvis.

Main Methods:

• 3D laser scanning of fossil and extant hipbones.
• Application of non-landmark-based and linear morphometric analyses.
• Functional morphological interpretation of pelvic features.

Main Results:

• Rudapithecus pelvis exhibits a unique mosaic of features, including an expanded acetabular lunate surface and shallow acetabulum.
• Features suggest adaptations for orthograde behaviors and arboreal locomotion, similar to extant apes.
• Absence of extreme lower iliac elongation, unlike extant great apes, indicates independent evolutionary pathways.

Conclusions:

• The Rudapithecus pelvis challenges the assumption that extreme lower iliac elongation is a prerequisite for orthograde posture in hominoids.
• Lower iliac elongation likely evolved independently in different great ape lineages.
• The last common ancestor of humans and chimpanzees may have possessed a pelvis unlike that of modern great apes.