Bony Fishes
Former Answer by some dummy: "The most diverse group is insects, which belong to the group ARTHROPODA*.*Arthropoda-Largest and most diverse animal phylum, mostly insects."This answer is completely wrong based on the question.Arthropods are invertebrates! They are the most numerous INvertebrates.The most diverse vertebrates are BONY FISH.
Amphibians
bony fishes
bony fishes
bony fishes
Cnidarians are the most diverse group.
Reptiles
Mammals are most familiar vertebrates .
a) jawless fishes.
mammals are the smallest group of vertebrates
The Arthropods are the largest and most diverse.
The rainbow XD lol