Abstract
The Cenozoic marked a period of dramatic ecological opportunity in Earth history due to the extinction of non-avian dinosaurs as well as to long-term physiographic changes that created new biogeographic theaters and new habitats. Snakes underwent massive ecological diversification during this period, repeatedly evolving novel dietary adaptations and prey preferences. The evolutionary tempo and mode of these trophic ecological changes remain virtually unknown, especially compared with co-radiating lineages of birds and mammals that are simultaneously predators and prey of snakes. Here, we assemble a dataset on snake diets (34,060 observations on the diets of 882 species) to investigate the history and dynamics of the multidimensional trophic niche during the global radiation of snakes. Our results show that per-lineage dietary niche breadths remained remarkably constant even as snakes diversified to occupy disparate outposts of dietary ecospace. Rapid increases in dietary diversity and complexity occurred in the early Cenozoic, and the overall rate of ecospace expansion has slowed through time, suggesting a potential response to ecological opportunity in the wake of the end-Cretaceous mass extinction. Explosive bursts of trophic innovation followed colonization of the Nearctic and Neotropical realms by a group of snakes that today comprises a majority of living snake diversity. Our results indicate that repeated transformational shifts in dietary ecology are important drivers of adaptive radiation in snakes and provide a framework for analyzing and visualizing the evolution of complex ecological phenotypes on phylogenetic trees.
Highlights
Evolutionary divergence in feeding ecology is a fundamental response to both ecological opportunity and interspecific competition, often involving coordinated change in prey preferences, foraging habitat, and trophic morphology [1,2]
We demonstrated how primary natural history observations can be integrated with stochastic model–based comparative methods to describe the evolution of complex ecological phenotypes
Prior comparative analyses have emphasized the deep historical roots of dietary differences observed in lizard [65] and snake [98] communities. Our results extend this perspective by explicitly quantifying reconstructed evolutionary dynamics of historical ecological transitions, revealing a dramatic ecological expansion in occupied diet space beginning in the mid-Eocene and elevated rates of trophic innovation following colonization of the Nearctic and Neotropical realms by major snake lineages
Summary
Evolutionary divergence in feeding ecology is a fundamental response to both ecological opportunity and interspecific competition, often involving coordinated change in prey preferences, foraging habitat, and trophic morphology [1,2].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
