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Updated: Aug 13, 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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Diet versatility and functional trade-offs shape tooth morphology in squirrels.
Iris Menéndez1,2, Donald L Swiderski3, Ana R Gómez Cano4
1Departamento de Geodinámica, Estratigrafía y Paleontología, Facultad de Ciencias Geológicas, Universidad Complutense de Madrid, Madrid, Spain.
Evolution; International Journal of Organic Evolution
|January 23, 2023
Summary
Dietary shifts drive significant evolutionary changes in squirrel tooth morphology, particularly the fourth lower premolar (p4). Specialized diets, like those including grass and fruits, lead to distinct tooth shapes, demonstrating adaptation beyond generalist dental morphology.
Area of Science:
- Evolutionary biology
- Paleontology
- Mammalian anatomy
Background:
- Understanding adaptation drivers is crucial for evolutionary diversity.
- Tooth morphology, a conserved trait, offers insights into evolutionary resistance.
- Squirrels exhibit stable dental morphology, making them ideal for studying evolutionary change.
Purpose of the Study:
- Investigate the evolutionary adaptations of tooth morphology in squirrels in response to diet.
- Determine the conditions that can overcome evolutionary resistance in conserved structures.
- Analyze the role of diet in shaping squirrel dental evolution.
Main Methods:
- Geometric morphometrics applied to the occlusal surface of the fourth lower premolar (p4).
- Analysis of squirrel species with diverse diets, including generalists, folivores, and bark gleaners.
- Comparative morphological analysis to identify diet-related tooth shape variations.
Main Results:
- Generalist diets favor ancestral tooth shape, while specialized diets induce morphological change.
- Species consuming grass and dry fruits show divergent p4 morphologies due to feeding trade-offs.
- Folivores tend to have larger p4s, while bark gleaners have smaller p4s.
Conclusions:
- Diet is a significant factor influencing squirrel tooth evolution, driving adaptation in p4 morphology.
- Trade-offs in feeding performance shape tooth morphology in response to specific dietary components.
- Factors beyond diet also contribute to the evolution of tooth morphology in squirrels.
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