Extended Data Fig. 7: Origins of gill function.
From: Ion regulation at gills precedes gas exchange and the origin of vertebrates
Our findings support a novel stem chordate or deuterostome origin for ion regulation at gills (pink), perhaps near the inception of pharyngeal gill pores and their role in filter-feeding (black). A vertebrate origin for gas exchange at gills (blue) with increasing body size and activity is also supported by this work, and consistent with fossil and developmental studies (references in text). Data not collected for clades in grey.
