Foraging mode constrains the evolution of cephalic horns in lizards and snakes

A phylogenetically diverse minority of snake and lizard species exhibit rostral and ocular appendages that substantially modify the shape of their heads. These cephalic horns have evolved multiple times in diverse squamate lineages, enabling comparative tests of hypotheses on the benefits and costs of these distinctive traits. Here, we demonstrate correlated evolution between the occurrence of horns and foraging mode. We argue that although horns may be beneficial for various functions (e.g., camouflage, defence) in animals that move infrequently, they make active foragers more conspicuous to prey and predators, and hence are maladaptive. We therefore expected horns to be more common in species that ambush prey (entailing low movement rates) rather than in actively searching (frequently moving) species. Consistent with that hypothesis, our phylogenetic comparative analysis of published data on 1,939 species reveals that cephalic horns occur almost exclusively in sit-and-wait predators. ..., , , # Foraging mode constrains the evolution of cephalic horns in lizards and snakes

[https://doi.org/10.5061/dryad.fqz612jzm](https://doi.org/10.5061/dryad.fqz612jzm)

This dataset contains the raw data and R codes to replicate our analyses.

## Description of the data and file structure

**1\_dataset.csv**: comma separated version of the original dataset (Table S1 – Electronic Supplementary Material), without references. To be used in the analyses with the R codes. This .csv file includes the following data:
-   Column ‘species’: scientific name
-   Column ‘taxon’: taxon (snake or lizard)
-   Column ‘forag\_cat’: foraging mode as categorical variable (sit-and-wait = SW; active foraging = AF)
-   Column ‘forag\_bin’: foraging mode as binomial variable (sit-and-wait = 1; active foraging = 0)
-   Column ‘horn\_cat’: horn presence as categorical variable (horned = HR; hornless = HL)
-   Column ‘horn\_bin’: horn presence as binomial variable (horned = 1; hornless = 0)

**2\_codes.R**: codes w...