Ecological drivers of jaw morphological evolution in lepidosaurs.

Area of Science:

• Evolutionary Biology
• Comparative Anatomy
• Paleontology

Background:

• Morphological evolution is influenced by ecology, phylogeny, and allometry.
• Lepidosaurs (lizards and snakes) exhibit remarkable diversity, making them ideal for studying evolutionary drivers.
• Understanding jaw morphology evolution is crucial for lepidosaur diversification.

Purpose of the Study:

• To quantify lower jaw morphological variation in Lepidosaurs.
• To investigate the roles of phylogeny, allometry, and ecology in jaw shape evolution.
• To determine the ancestral jaw use in lepidosaurs.

Main Methods:

• Utilized three-dimensional geometric morphometrics.
• Analyzed a broad sample of 153 lepidosaur species.
• Assessed the influence of ecological factors (diet, foraging, substrate) and phylogeny.

Main Results:

• Phylogeny significantly influenced mandibular shape evolution; snakes diverged from lizard-like jaws.
• Allometry and ecological factors (diet, foraging, substrate) drive mandibular diversification.
• Ecological groups show distinct patterns in disparity, convergence, and evolutionary rates.
• Lepidosaurs ancestrally used jaws for prey capture, not primarily for tongue prehension.

Conclusions:

• Morphological innovation in the mandible is a key factor in lepidosaur ecomorphological diversification.
• Divergent evolutionary mechanisms explain the acquisition of diverse diets and habitats.
• Jaw morphology evolution is a complex interplay of phylogenetic, allometric, and ecological factors.