 Mosasaurs probably evolved from an extinct group of aquatic lizards known as aigialosaurs in the Early Cretaceous.Dolichosauridae is a family of Late Cretaceous aquatic varanoid lizards closely related to the mosasaurs.The position of the lizards and other Squamata among the reptiles was studied using fossil evidence by Rainer Schoch and Hans-Dieter Sues in 2015.