Most forms resemble modern newts, with elongate flatened tails.
A few late specialised forms however developed strange boomerang-shape heads. These remarkable heads probably served as hydrofoils to provide lift in slow-moving streams. The nectridea were a succesful group for a while, but were unable to cope with the drying out conditions at the end of the Permian, and died out without leaving any descendents. The boomerang headed forms have no modern counterpart.