https://www.selleckchem.com/pr....oducts/glafenine.htm
The vertebrate jaw is thought to have evolved through developmental modification of the mandibular arch. An extant jawless vertebrate, the lamprey, possesses a structure called "velum"-a mandibular arch derivative-in addition to the oral apparatus. This leads us to assess the velum's possible contribution to the evolution of jaws. The velar muscles develop from progenitor cells distinct from those from which the oral muscles develop. In addition, the oral and velar regions originate from the different sub-population of the trigeminal