Vertebrate Diversity

Vertebrates are animals with a backbone, which is a structure that protects the spinal cord and supports the body.

They also have a skull to protect the brain, an internal skeleton for movement and organ protection, and a well-defined head with sense organs to interact with their surroundings.

Despite these shared traits, vertebrates are classified into five major groups.

The first group, fish, is further divided into three groups.

First, the jawless fish, like lampreys, lack jaws and scales.

Next are the cartilaginous fish, like sharks, with flexible cartilage skeletons.

Finally, bony fish, like tuna, have skeletons made of bone.

Moving to land, amphibians, like frogs and salamanders, live both in water and land, breathing through lungs and skin.

Next, reptiles, such as snakes, lizards, and turtles, thrive with scaly skin and amniotic eggs adapted for dry habitats.

Next come birds, like parrots and penguins, which have feathers and lay eggs with protective shells.

Finally, mammals, like bears, nourish their young with milk from mammary glands and typically have hair or fur.