Chemoreception (including olfaction, vomerolfaction, and gustation) is the ability to detect and process chemical signals, a crucial sense for vertebrate survival. Over recent decades, our understanding of chemosensory mechanisms has drastically improved, especially in mammals. In contrast, squamates, particularly lizards, have received less attention despite their unique tongue-flicking behaviour, which is intimately linked to their chemosensory system. Moreover, the anatomical relationships between the vomeronasal organ and the nasal cavity across squamates have been largely overlooked. Advances in CT technology and high-quality squamate genomes now offer an excellent opportunity to study squamate chemoreception from a new perspective. In this work, we synthesize current knowledge of squamate chemoreception using an integrative approach that incorporates comparative anatomy, development, physiology, behaviour, histology, and genomics. By generating standardized figures from newly acquired CT scans covering all squamate families, we discuss evolutionary patterns in the vomeronasal organ, choanal groove, lacrimal duct, tongue, lateral nasal conchae, and olfactory bulbs. Additionally, we provide synonyms for different structures present in the nasal cavity of squamates, and propose new hypotheses addressing previously overlooked aspects of squamate chemosensation, establishing a strong foundation for future research.
As usual, we will also broadcast via zoom for those who can not join in person: https://zoom.us/j/94510498226