Mammals are defined as being warm-blooded, air breathing vertebrates with hair or fur and the ability to nurse their young, notes the San Diego Zoo website; humans and some bat species are examples of mammals without vis... More »

Most animals without backbones, known as invertebrates, have no tails. Among these are spiders, most insects and frogs. However, every species of mammal has a tail at some point in its development. Human embryos possess ... More »

A red-tail boa is a large South American boa constrictor with a 30-year life span. Its name comes from the reddish pattern on its tail. Typically, an adult red-tail boa is 8 to 10 feet long and weighs about 50 pounds. More » Pets & Animals Reptiles Snakes

While different breeds of fox have different colorations, in general foxes are small canine mammals with a full coat of fur, pointy ears, long bodies and distinctive bushy tails. Foxes walk on four legs and have small he... More »

The five main groups of vertebrates, known as classes, are: fish, amphibians, reptiles, birds and mammals. Vertebrate species are assigned groups based on shared traits, such as body covering, the ability to maintain a s... More »

All mammals are vertebrates. A vertebrate is any living being with a backbone or a spine. More »

Foxes are four-legged mammals with bushy tails, pointed ears and long snouts. They are genetically related to dogs and have a vaguely doglike appearance that includes sharp teeth and clawed paws with pads. More »