The 7 classes of vertebrates By Alissa Hindman

Agnatha The oldest class Jawless It includes lampreys which is a fish There are no paired fins 7 external gill openings

Chondrichthyes have skeletons made up of cartilage Sharks is an example of this class They lack ribs They don't have bone marrow

Osteichthyes Most diverse class They are also known as bony fish Most are carnivorous Some are herbivores 95% of fish are these kind An example is an Atlantic Herring

Amphibia Most undergo metamorphosis Most lay eggs in the water Their are approximately 6,500 species

Reptilia Includes snakes, crocodiles, and alligators Breathe air Lay eggs in shells Most are in every continent They don't have an a

Aves An example of this class woud be birds Distinguished by feathers Over 10,000 living species no teeth Emerged around 160 million years ago

Mammalia Air- Breathing verebrates Have teeth, sweat glands, and middle ear bones Have hair or fur All females nurse their young

Chordata Groups

Over all chordata Notochord- a flexable skeletal support rod embedded in the animal's back Hollow nerve bove cord- runs along the animal's back Pharyngeal slits- slits through the body wall in the pharynx Tail- extends beyond the anal opening as well as the rest of the animal

Vertebrates large active animals that have a well- developed brain The brain is encased in a hard skull One example is lions

Tunicates Also known as the urochordates Includes free- swimming and sessile animal's One is a sea- squirts

Lancelets Also known as cephalochordates Small eel- like animals All can swim Spend most of their lives buried in sand Commonly found in shallow tropical oceans Most are filter feeders One example is eels