Reconstructing the origin and early evolution of the snake brain

Area of Science:

• Paleobiology
• Evolutionary Biology
• Herpetology

Background:

• Snakes are diverse vertebrates, but their ecological origins and early evolution remain debated.
• Limited fossil evidence and limitations of osteological traits hinder evolutionary reconstructions.

Purpose of the Study:

• To investigate the ecological origins and early evolution of snakes.
• To reconstruct ancestral snake lifestyles using ecomorphological hypotheses.

Main Methods:

• High-definition brain reconstructions of extant Squamata (lizards and snakes).
• Ecomorphological hypothesis testing using predictive models.
• Quantitative tracking of phenotypic diversification in soft tissues, including brain morphology.

Main Results:

• Predictive models suggest a burrowing lifestyle with opportunistic behavior at the origin of crown snakes.
• A complex ancestral mosaic brain pattern was inferred.
• Phenotypic diversification of soft tissues, particularly the cerebellum, is crucial for understanding evolution.

Conclusions:

• The study provides new insights into snake evolutionary origins, emphasizing a burrowing ancestor.
• Reconstructing soft tissue morphology, like the brain, is vital for paleobiology, especially when fossils are scarce.
• Combining extant and extinct data with soft tissue and osteological traits offers a powerful approach for tracing deep evolutionary history.