Comparative Sulcal Morphology of the Late Miocene Fossil Ape, Rudapithecus hungaricus.

Area of Science:

• Paleoanthropology
• Primatology
• Neuroscience

Background:

• Fossil hominoid endocasts are exceptionally rare, with limited detailed analyses available.
• The Ekembo nyanzae endocast is the sole previously analyzed fossil ape endocast.
• Rudapithecus hungaricus cranial remains offer a unique opportunity to reconstruct endocranial morphology.

Purpose of the Study:

• To provide the first complete description of the Rudapithecus sulcal pattern.
• To compare the Rudapithecus sulcal pattern with extant non-hominin hominoid sulcal patterns.
• To infer the primitive brain condition in hominine evolution.

Main Methods:

• Analysis of sulcal patterns from Rudapithecus endocasts.
• Comparison with classical descriptions of hominoid sulcal patterns.
• Comparative analysis with a sample of extant non-hominin hominoid endocasts.

Main Results:

• A hominid-like sulcal pattern was identified in Rudapithecus.
• The Rudapithecus sulcal pattern is more complex than hylobatids but simpler than Pan.
• The sulcal pattern shows affinities to Gorilla and Pongo, particularly Gorilla.

Conclusions:

• Rudapithecus crania reveal a de-coupling in hominid brain evolution.
• Cranial shape is African ape-like, endocast shape is primitive, and sulcal pattern is hominid-like.
• Rudapithecus endocasts provide evidence for the primitive brain condition in hominine evolution.