Evolution And Morphology Of The Tetrapod Brachial Plexus

The brachial plexus is formed by interconnected spinal nerves that give rise to branches which innervate the muscles associated with the pectoral limb. Historically, the utility of this anatomical structure has largely been associated with practical medical and veterinary interests, although recently the utility of the plexus in understanding mammalian evolution has been explored. In this study, we examine published and novel dissections of the brachial plexus across a broad range of tetrapod taxa for common traits using character optimization, sometimes known as trait mapping. Each of the major clades of tetrapods is included in the analysis, as are major clades of mammals following from published records. Our results indicate that the overall dorso‐ventral patterning of the brachial plexus is a highly conserved trait, while other features of seem to characterize large clades. Autapomorphies are common throughout the plexus. The traits that characterize large clades may be indicative of developmental or functional constraints on brachial plexus morphology. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .