With over 2 million species, Kingdom Animalia is the largest of the kingdoms. It encompases a huge diversity of creatures, some of which we might not even think of as animals - like sponges (pictured right).
While mammals, birds, reptiles, amphibians, and fish are the most familiar to us, over half of all the animal species are arthropods like the butterfly picured right.
Chordates are defined as organisms that possess a structure called a notochord, during at least one part of their development. The notochord is a flexible cartilage rod that extends most of the length of the back. It lies above the gut but below the spinal cord and stiffens the body to act as support during movement. While some marine animals have a notochord throughout their entire adult life, most mammals, including humans, lose theirs prior to birth.
Chinchillas, along with all other vertebrates, are also memebers of the Subphylum vertebrata (not described here)
All mammals share at least three characteristics not found in other animals: 3 middle-ear bones, hair, and the production of milk by modified sweat glands called mammary glands. Class mammalia contains a vast diversity of forms. The smallest mammals are found among the shrews and bats, and can weigh as little as 3 grams. The largest mammal, and indeed the largest animal to ever inhabit the planet, is the blue whale, which can weigh 160,000 kg.
With over 2000 living species, rodents are by far the largest group of mammals. Rodents range in size from 5 grams over 70 kg!! They are found everywhere around the world except in Antarctica, New Zealand, and on some oceanic islands.
Despite all of this diversity, all rodents share one characteristic: their teeth are highly specialized for gnawing. In fact, their front teeth grow constantly (like our finger nails) so rodents must continuously chew on things like wood to keep their teeth trimmed.
Chinchillas, along with degus and capybaras, are also members of Suborder Caviomorpha (not described here).
Members of Family Chinchillidea are found along the central and southern Andes and throughout most of Patagonia in southern South America.
These creatures are medium (500 grams) to large-sized rodents (8kg) with thick, soft fur. Their powerful and well-developed hind limbs are significantly longer than the forelimbs. They have large eyes and ears, and bushy tails that range from short up to about 1/3 the length of the body. The forefeet have four toes, which are used for grasping. The pads of their feet also have fleshy bumps called papillae which act like extra fingrs and aid in gripping onto small objects.
The two kinds of animals pictured here, visachas (pictured above) and chinchillas (pictured below), use their strong hind legs for jumping, but mostly they move on all four limbs (hopping like rabbits). Chinchillas and mountain viscachas live in mountainous, rocky areas, where they move over and through the rocks with great agility. Plains viscachas live in the great plains areas of Argentina, from the Chaco in the north to Patagonia in the south.
Chinchillas, mountain viscachas, and plains viscachas are all colonial, living in groups that range from a few individuals to hundreds. Unfortunately, chinchillas are nearly extinct in the wild, so little is known of their behavior under natural conditions. Viscachas, once abundant, are now seriously threatened and uncommon. Mountain viscachas are uncommon and live in remote areas.
Chinchilla lanigera is the most common species of chinchilla found today as housepets. Adults are approximately 10 inches in length, not including a 5 inch tail. The species is sexually dimorphic (males and females look different) with the female weighing up to 800 g and the male only 600 g. The adults ears are rounded and approximately 1.8 inches long
C. lanigera has a plush coat which consists of hairs 1-2 inches long. Their hair grows in clusters of 50-75 individual strands. For every two clusters of hairs, a single guard hair grows in the center and is much taller than the surrounding hair. Their natural color pattern, known as Agouti, appears as gray body fur with a white belly (see the section entitled Colors for more information). Since chinchillas were first brought to America in 1927, breeders have created an impressive line of other colors.
C. brevicaudata, which literally means "short tail", is derived from the fact that this species of chinchilla has a much shorter tail than their cousin species, C. lanigera. Short-tailed chinchillas have a body length of 12 to 13 inches and a tail length of 3 to 4 inches. Females are typically larger than males. C. brevicaudata may be distinguished from C. lanigera by its smaller ears and overall larger size. In addition, C. brevicaudata has 20 tail vertebrae compared to 23 in C. lanigera.