Question

List the characteristic features that distinguish cartilaginous fishes with living jawless fi shes

Answer 1

Chondrichthyes is a class that contains the cartilaginous fishes: they are jawed vertebrates with paired fins, paired nares, scales, a heart with its chambers in series, and skeletons made of cartilage rather than bone. The class is divided into two subclasses: Elasmobranchii and Holocephali.

Agnatha is a superclass of jawless fish in the phylum Chordata, subphylum Vertebrata, consisting of both present and extinct species. The group is sister to all vertebrates with jaws, known as gnathostomes.