Morphoarchitectural variation in South African fossil cercopithecoid endocasts

Area of Science:

• Paleoneurology
• Primate Evolution
• Comparative Anatomy

Background:

• Limited studies characterize external brain morphology in Plio-Pleistocene cercopithecoids despite abundant fossil crania.
• Advancements in imaging and computational tools enable detailed virtual analysis of endocranial casts.

Purpose of the Study:

• To investigate the endocranial organization of 14 Plio-Pleistocene cercopithecoid specimens from South Africa.
• To provide the first detailed comparative description of external neuroanatomy in these extinct primates.

Main Methods:

• X-ray microtomography-based 3D virtual imaging and quantitative analyses.
• Semi-automatic neocortical sulcal pattern extraction.
• Landmark-free surface deformation for morphostructural analysis.

Main Results:

• Reconstruction of endocranial volumes for extinct South African cercopithecoid taxa.
• Detailed comparison of sulcal pattern variations, particularly the central sulcus in Theropithecus oswaldi subspecies.
• Neuroanatomical assessment of Cercopithecoides williamsi, showing similarities to papionin patterns.

Conclusions:

• The study presents novel comparative data on Plio-Pleistocene South African cercopithecoid neuroanatomy.
• Findings offer insights into primate brain evolution and potential phylogenetic/taxonomic implications.
• Further virtual paleoneurology research across wider geographic areas is recommended to understand cortical evolution.