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Endocranial shape variation and allometry in Euarchontoglires.
Madlen M Lang1, Camilo López-Aguirre2, Lauren Schroeder3,4
1University of Toronto Scarborough, Scarborough, ON, M1C 1A4, Canada. madlen.lang@mail.utoronto.ca.
Scientific Reports
|August 2, 2024
Summary
This study reveals distinct endocranial shape patterns across Euarchontoglires, showing significant phylogenetic differences and varying allometric relationships between brain size and shape, particularly in platyrrhines and rodents.
Area of Science:
- Evolutionary biology
- Comparative anatomy
- Paleoneurology
Background:
- Brain size in Euarchontoglires is well-researched, but brain shape and its allometric trajectories remain less understood.
- Understanding these patterns is crucial for deciphering evolutionary trends within this diverse group.
Purpose of the Study:
- To analyze endocranial shape variation and allometry across extant euarchontoglirans.
- To identify phylogenetic patterns and group-specific allometric relationships in brain shape.
Main Methods:
- Utilized 3D geometric morphometric analyses on digital cranial endocasts from 140 euarchontogliran species.
- Applied Principal Component Analyses and ANOVAs to assess shape variation, phylogenetic signals, and allometric effects.
Main Results:
- Endocranial shape exhibits clear phylogenetic patterns with significant differences among major clades (e.g., Platyrrhini, Strepsirrhini, Rodentia).
- Allometry significantly impacts endocranial shape across Euarchontoglires, with notable variations in scaling relationships among groups.
- Platyrrhines show the strongest size-shape relationship, while rodents display the most shape diversity.
Conclusions:
- Fundamental differences exist in how brain shape and size covary across Euarchontoglires.
- These varying allometric patterns may have contributed to the adaptive radiations observed in this superorder.
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