Vertebrata Classes

The Subphylum Vertebrata can be further categorized into classes. Vertebrates have a skull and a spine. The parts of the skeleton that form the spine are called vertebrae. The skeleton can be made of bone or cartilage.

Placodermi: Armored Fish

The now extinct placoderms had strong armor covering their head.

Agnatha: Jawless Fish

These fish have a cartilaginous skeleton (a skeleton made of cartilage).

Chondricthyes: Cartilaginous Fish

These fish have a cartilaginous skeleton.

Osteichthyes: Bony Fish

These fish have a bony skeleton (a skeleton made of bones).

Amphibia: Amphibians

This group includes frogs, salamanders, newts, and caecilians.

Reptilia: Reptiles

This group includes lizards, crocodilians, snakes, and turtles.

Aves: Birds

Birds are descendants of feathered dinosaurs.

Mammalia: Mammals

All mammals have hair and produce milk.