There has been an increase in the number of chambers

There has been an increase in the number of chambers in heart during evolution of vertebrates. Give
the name of the class of vertebrates having two, three or four chambered heart.

(a) Two chambered heart—Pisces
(b) Three chambered heart—Amphibia and reptiles except crocodiles .
© Four chambered heart—Crocodiles, aves and mammalia