Just to Name a Few . . .

Mammals are animals which raise their young on milk and typically give birth to live young. Most mammals are covered with hair or fur, the difference between the two is fur grows to a certain length and then falls out, while hair continues to grow indefinitely, which is why some will take their dog to the groomer regularly for hair cuts and the cat never needs one. Most mammals have specialized teeth that help them to cut or chew their food. Compared to other vertebrates, mammals have highly developed nervous systems and sensory organs, and have intelligence and resourcefulness that few other animals can match. Mammals are probably the most familiar members of the animal kingdom, including our cats and dogs, elephants, whales and dolphins, and the species that now dominates life on earth, human beings.

Mammals inhabit just about every corner of the Earth. From the Polar bears living on Arctic ice and Arctic foxes surviving temperatures as low as �68� C (-90� F), to camels and kangaroo rats thriving in deserts, tolerating high temperatures that could easily kill animals from cooler environments. You will also find mammals high on treacherous mountain slopes where the air is thin, right down to the deepest depths of the oceans where the pressure would instantly crush an animal from a land habitat.

Marsupial is the common name for the group of mammals we recognize by the pouch in which the female will carry offspring. Some more well known marsupials include the kangaroo, koala, wombat, and opossum. Also including the lesser known numbat, bandicoot, ringtail possum, and thylacine. Marsupials are as diverse in size as they are in appearance, ranging in size from the ningaui, mouse-like in appearance measuring about 5 cm (2 in) long and weighing only 2.8 g (0.1 oz), to the gray and red kangaroos, reaching lengths of 2.5 m (8 ft), standing as tall as 1.8 m (6 ft), and weighing out around 90 kg (200 lb). Marsupials have come to live in a wide range of places, some occupy arboreal habitats (living in trees), while others live their lives underground, some live in deep thick forests and others inhabit the open plains.

The most important trait the marsupials possess is the lack of a true placenta in pregnant females. In other mammals, the placenta serves to remove wastes and provide nutrients to the developing embryo. The female marsupial forms a type of yolk-sac in her uterus from which the embryo absorbs nutrients for about five weeks. The embryonic animal then emerges, crawling and wriggling from the birth canal. Immediately after birth, the tiny offspring makes its way along its mother's body toward a nipple located inside an abdominal pouch or within the folds of skin. The newborn attaches itself firmly to a nipple to suckle its mother's milk. The offspring may remain with the mother until it is more than a year old, returning to her pouch for nourishment or safety.

Birds, our fine feathered (and winged) friends. Birds are the only animals with feathers, many others may have wings to fly with, none have feathers. Most birds are flying creatures, even the now flightless ostriches and penguins evolved from ancestors quite capable of flight.

The reason birds are able to fly is largely due to their physical make-up. Putting aside the outwardly obvious, wings and feathers, the internal body parts of all birds, including flightless ones, show the evolution of birds as flying animals. Birds have lightweight skeletons in which many of the major bones are hollow. Unique to the skeleton of birds is the furculum, or wishbone. When in flight, the furculum not only aids the animal in breathing, but acts as a shock absorber against the great force of wing movement. In almost every way the bird has adapted to flight, not only reducing body weight, but concentrating that weight towards the birds center of gravity, for example: Birds lack teeth, making their heads lighter, food is ground in the gizzard in the bird's core. Eggs are laid instead of the mother carrying the young inside her. Light skeletons, hollow bones, and of course, feathers.

Birds come in all shapes and sizes, from the bee hummingbird, which measures about 57 mm (about 2.25 in) from beak tip to tail tip and weighs 1.6 g (0.06 oz), to the ostrich, which stands 2.7 m (9 ft) tall and weighs up to 156 kg (345 lb). The great bustard is the heaviest bird capable of flight, coming in at weights up to 18 kg (40 lb).

Fish are a diverse group of animals that live and breathe in water. Fish are recognized by their fins, scales, which serve as protection, and the streamline shape of their bodies, which aids them in moving through the water. All fishes are vertebrates and are equipped with gills for breathing. Some fish, such as the Betta (gourami family, Belontiidae, classified as Betta splendens) have what is called a labyrinth organ in a cavity above each gill chamber used in breathing air. These organs allow the Betta and other "labyrinth" fish to survive in stagnant, oxygen poor water which could not be tolerated otherwise. Over 25,000 species of fish have been identified, and we discover hundreds more each year. Equally diverse is the size and shape these animals come in, from huge whale sharks that can grow to 12 m (40 ft) in length to the smallest vertebrate, a tiny goby, measuring only 1 cm (0.4 in) long.

We can find fish in almost all waters of the planet, excluding only the harshest of water environments, such as the Dead Sea. Fish with special "anti-freeze" chemicals in their blood inhabit the below freezing waters of the Arctic. Desert pupfish survive quite well in the hot springs of western North America where temperatures are often higher than 40� C (100� F). Killifish living in the tropics of South America and Africa release their eggs, or spawn, as the dry season begins. Their eggs then lie dry in the ground for sometimes six months, until the next rain returns when their short life cycle begins again. In the deepest oceans, sunlight cannot reach the inhabitants and many fishes cooperate with glowing bacteria to create their own light (Bioluminescence) for communication, mating and to capture prey.

Amphibians are animals with moist, hairless skin which water passes through, both in and out. Almost every amphibian lives the first part of its life in the water, emerging to live the remainder of life on dry land, but usually in or near water still. Amphibians were the first vertebrates to adapt to life on land.

Amphibians live everywhere on Earth save Antarctica with the most widespread being frogs, which can be found almost everywhere except a few islands, and the driest of deserts. Salamanders inhabit the western hemisphere from North America to the northern part of South America. They're also found in Europe, the Mediterranean area, Asia, and Africa. Caecilians, wormlike amphibians lacking legs, are more limited in their range, found in Central and South America, parts of Southeast Asia, and from India and Sri Lanka to the Philippines. Amphibians inhabit many different ecosystems, including grasslands, rain forests, alpine areas and conifer forests, even deserts, although most need freshwater habitats such as swamps and streams, or other wet environments for breeding.

Invertebrates are animals lacking a backbone (vertebral column). Invertebrates are the majority of the animal kingdom. The invertebrates range from the simple sponges to advanced animals such as insects and cephalopod (squids, cuttlefish, octopus) mollusks. Deep-sea collecting techniques show enormous biodiversity on the ocean floors, comprised mostly of invertebrates numbering in the tens of millions.

Sponges are animals which live at the bottom of our oceans and other bodies of water. They spend their lives attached to rocks, plants, and other objects beneath the water's surface. Sponges cannot move about and were once thought of as plants, but since they do not manufacture their own food but must eat, they are classified as animals. There are over 5,000 species of sponges inhabiting oceans and fresh water bodies from warm shallow to cold deep waters.

Coral is the limestone formation we often see as reefs, like the Great Barrier Reef of Australia, and is formed by millions of tiny animals. Coral formations may also take on the appearance of branching trees, domes or organ pipes.