Adelosaurus huxleyi (Hancock and Howse 1870, Evans 1988) was originally and later considered to be a small and distinct species of Protorosaurus. Here, derived from a sister to Acerosodontosaurus, Adelosaurus was a sister toThadeosaurus, Hovasaurus and the rest of the Enaliosauria.
Distinct from Acerosodontosaurus, Adelosaurus was half as long and more gracile. The humerus did not have an expanded distal end. The carpus and hand were relatively smaller. The hind limb was longer and more gracile. The proximal metatarsals were all subequal in width.
Adelosaurus was the most terrestrial of the known enaliosaurs, showing few aquatic characters. Evans (1988) considered the incomplete ossification of joint surfaces as evidence for immaturity or an aquatic lifestyle.
The family tree of the Enaliosauria is here. The complete reptile family tree is here.