When a general morphology allows many habitat uses.

Area of Science:

• * Zoology
• * Functional Morphology
• * Evolutionary Biology

Background:

• * Functional morphology integrates internal and external anatomy for a deeper understanding of locomotion.
• * Previous studies have highlighted the importance of detailed anatomical data in evolutionary research.

Purpose of the Study:

• * To investigate stabilizing selection on hind limb traits in Tropiduridae and Liolaemidae lizards.
• * To determine if habitat specialization correlates with distinct morphological features.
• * To compare ecomorphological trends between these two lizard lineages.

Main Methods:

• * Analysis of muscle-tendinous and external hind limb morphology traits.
• * Application of evolutionary models, including the Ornstein-Uhlenbeck model, to assess selection pressures.
• * Comparative analysis of morphological data across different species and habitats.

Main Results:

• * The Ornstein-Uhlenbeck model best explains the evolution of hind limb traits, indicating stabilizing selection.
• * Clear ecomorphological trends were observed in both Tropiduridae and Liolaemidae, with sand lizards showing the most specialized traits.
• * Internal morphology traits demonstrated greater flexibility than external traits, impacting ecomorph identification.

Conclusions:

• * Stabilizing selection plays a significant role in shaping hind limb morphology in these lizard families.
• * Habitat specialization is associated with distinct morphological adaptations, particularly in sand lizards.
• * Differences in trait flexibility between internal and external morphology influence the identification of shared ecomorphs.