Neoselachii
subclass of fishes
The Neoselachii are an important group of cartilaginous fish in the subclass Elasmobranchii, class Chondrichthyes.
The group is important because it includes all living sharks, skates, and rays. They rapidly diversified during the Upper Triassic.
The group is descended from a primitive type of shark in the Devonian period.[1]