A fully segmented 3D anatomical atlas of a lizard brain.

As the relevance of lizards in evolutionary neuroscience increases, so does the need for more accurate anatomical references. Moreover, the use of magnetic resonance imaging (MRI) in evolutionary neuroscience is becoming more widespread; this represents a fundamental methodological shift that opens new avenues of investigative possibility but also poses new challenges. Here, we aim to facilitate this shift by providing a three-dimensional segmentation atlas of the tawny dragon brain. The tawny dragon (Ctenophorus decresii) is an Australian lizard of increasing importance as a model system in ecology and, as a member of the agamid lizards, in evolution. Based on a consensus average 3D image generated from the MRIs of 13 male tawny dragon heads, we identify and segment 224 structures visible across the entire lizard brain. We describe the relevance of this atlas to the field of evolutionary neuroscience and propose further experiments for which this atlas can provide the foundation. This advance in defining lizard neuroanatomy will facilitate numerous studies in evolutionary neuroscience. The atlas is available for download as a supplementary material to this manuscript and through the Open Science Framework (OSF; https://doi.org/10.17605/OSF.IO/UJENQ ).