Technically, domestic cats belong to the class Mammalia (mammals), the order Carnivora (meat-eaters), the family Felidae (cats), the genus Felis (lesser cats), and the species cattus (domestic cats): that's our cat, Felis cattus. There are three genera of the family Felidae: Panthera, the large or greater cats; Acinonyx, the cheetahs; and Felis, the small or lesser cats. A fourth genus, Smilodon, the saber-toothed tigers, just missed by only 12,000 years: almost no time at all, geologically speaking.

Since there is of necessity a lot of discussion about cat sizes using the terms "large" and "small," we shall use the terms "greater" and "lesser" in reference to the genera. The terms "greater cats" and "lesser cats" refer to size only in general: the larger lesser cats are larger than the smaller greater cats. The most obvious difference between the two genera is that greater cats can roar and the lesser cats cannot. The ability to roar is determined by the structure of the throat: most significantly, the small bones (the hyoid bones) that support the larynx. In the greater cats, these bones have been partially replaced by cartilage, allowing extraordinary flexibility of the throat and enabling the cat to roar. In the lesser cats, these bones are rigid and roaring is impossible. Contrast the deep-throated, deafening roar of a lion to the snarling cough of a puma.

The genera are divided into species. Generally speaking, two dissimilar animals belonging to the same genus are considered as belonging to different species if they do not interbreed and produce viable offspring: they either physically cannot interbreed, such as a puma and a housecat (boggles the mind, not to mention the housecat!); would not interbreed naturally, such as a jaguar and a leopard, which just don't have the right smells and signals to inspire mating; or their offspring would be sterile, such as a lion and a tiger, whose offspring is a "liger" if the father is a lion or a "tigon" if he is a tiger, but is always sterile. Conversely, if two such animals do interbreed and produce viable offspring, they naturally and quickly become the same species even if they weren't to start with -- interbreeding will do that sort of thing -- though they may maintain enough differences to be classed as separate subspecies.

There are some notable exceptions to this rule, particularly where man has interfered. The species Geoffroy's cat, for example, can physically mate with the domestic cat and produce viable offspring, but would not normally do so in the wild, as the smells and signals are wrong and the mating instinct would not be triggered. Man has successfully circumvented this, however, and produced viable offspring in a attempt to produce cats with wildcat patterns. Such hybrid off spring are usually treated as a subspecies of one species or the other, based upon dominant characteristics: so far, only new subspecies of Geoffroy's cat have been produced, not new domestic cats. This is not the case with other hybrids, most notably the Bengal is a domestic cat-leopard cat hybrid. Differing species come about through isolation. If some members of a species become separated from the main body of their species by distance or natural obstruction, they will eventually evolve into a different species, losing the ability to interbreed.

All members of the genus felis, subgenus felis, have a somewhat complex relationship to each other. The parent species in this group is Felis sylvestris, the European wildcat, who first evolved some 600,000 years or so ago in central Europe (where he can still be found). During the Second Ice Age, he extended his domain into Africa and Asia. As the ice receded the seas rose and the climates changed, the immigrant species became isolated from each other by water, deserts, and mountains. Over time, the isolated subspecies evolved into the Sand Cat, the African Wildcat, the Forest Cat, the Black-Footed Cat, and the Chinese Desert Cat: other species also evolved, but failed to survive. Species are themselves further divided into subspecies (if wild) or breeds (if domesticated): the two classifications are analogous to each other. We should remember that Panthera leo azandica (the Congo Lion) has exactly the same relationship to Panthera leo that Siamese Cat has to Felis cattus.

Don't be fooled by the Latin: if a zoologist set up a "zoo" of domestic cats, he'd find a Latin or Greek word for "Siamese," tack it on the end of "Felis cattus," and call it a subspecies. It would still be a breed. All felids, regardless of genus or species, have certain basic things in common.

In appearance, they all look like cats. While this may be arguable in the case of the Jaguarundi and, to a lesser degree, the Flat-Headed Cat, it is definitely not true of some other families: all members of the canid (dog) family, for example, do not look like dogs (not even all dogs look like dogs!). Besides a similarity of appearance, all cats have retractable claws: even the cheetah, the most primitive of all modern cats, has partially-retractable claws. The most cat-unique common characteristic, however, is purring: all cats, and nothing but cats, purr. For some time it was believed that the greater cats didn't purr: some texts still say this even today. This is patently not true, all cats purr: lions purr, tigers purr, cheetahs purr, leopards purr, jaguars purr, pumas purr, bobcats purr, domestic cats purr; all cats purr, without exception. This alone proves common ancestry: probably Pseudailurus, 28 million years ago, or Dinictis, 40 million years ago, depending upon whether saber-toothed tigers purred, something our own Neanderthal and Cro-Magnon ancestors failed to note.

There are also a whole slew of internal similarities, as would be expected. Besides the biological similarities among cats, which one would expect, there is one other distinguishing characteristics. Wherever it has adapted, in whatever ecological niche in whatever part of the world, the cat reigns supreme among carnivores in its size class. It is the penultimate hunter, with a finely-honed stalking and killing ability that other carnivores can only dream about. The typical member of family Felidae scores in 30 percent of its hunts: no other carnivore, including man, comes close. It is also a merciful hunter, killing quickly and cleanly by severing the spinal column of its prey and minimizing the pain and suffering.

Some zoologists break the three genera down further into subgenera based upon subtle or newly-discovered differences. As an example, the subgenus Leopardus, the South American lesser cats, have 36 chromosomes instead of the usual 38, (probably through a fusion of two chromosomal pairs). This is a major distinction, even though it is invisible to the eye and depended upon modern technology for its discovery, and is usually considered a legitimate subgenus. The subgenus Lynx, on the other hand, is based upon the lynx and its relatives having short tails and tufted ears, a more obvious but also more trifling distinction. The subgenus of a wild species is given in brackets in the species list, and would replace the genus in nomenclature: "Felis [Puma] concolor" may be "Puma concolor" instead of "Felis concolor," but never "Felis puma concolor." The relationships between subgenera can be clearly seen in the family chart.

All species of cats have differing subspecies (breeds), not just the domestic cat. There are, for example, nine subspecies of lions: Panthera leo azandica: Congo Lion Panthera leo bleyenberghi: Bleyenbergh's Lion Panthera leo hollisteri: Hollister's Lion Panthera leo massaicus: Massai Lion Panthera leo persica: Persian Lion Panthera leo roosevelti: Roosevelt's Lion Panthera leo senegalensis: Senegal Lion Panthera leo somaliensis: Somalian Lion Panthera leo verneyi: Verney's Lion The difference in lion subspecies reflects variations in size, color, territory, etc., with the names coming from the discoverer, classifier or territory.

The number of recognized subspecies of a wild cat species will be given, but individual subspecies will not be named. One small footnote: don't let the "scientific" name of the various cats fool you. Zoologists are as silly as the rest of us when it comes to naming things, but they hide their silliness behind a Latin or Greek facade. As an example, the scientific name for the common stripped skunk, mephitis mephitis, translates to "smelliest of the smelly." In our own case, the Latin word "felis," generic for "cat," is derived from the older Latin word "felix," meaning "happy," probably because cats are not shy about letting the world know when they are happy, which is most of the time: they purr (purring also makes the cat owner feel happy).

This means that "felis cattus" could be translated as "happy cat" or "purring cat," and the family "Felidae" means "one of those who are happy." Deep stuff here! In order to be fair, and to give the zoologists their due, the Romans did call just any old cat "cattus," and one of their cats "felix cattus." (No, "felix cattus" does not mean "Felix the Cat," though we can see where Otto Messmer may have gotten the name.) The Species of Cat All in all, there are 38 recognized species of cats: six greater cats, panthera; one cheetah, acinonyx; and 31 lesser cats, felis, including the domestic cat.

All of them except the domestic cat (and even some of those) have one thing in common: they are wild carnivores and will often bite and scratch when encountered (bigger ones may also eat!). Count your fingers after petting! A description of each of the 38 species is given. Considerable thought went into the order in which the species should be listed. Most lists give the greater cats, then the cheetah, then the lesser cats, with the order within each genus being either the alphabetical order of their English or Latin names or the territory in which they were first discovered. None of this seemed to make sense here, so we decided to list them by weight and size, largest to smallest. Alter nate English names are given after the primary name, and subgenera are given in brackets.

The weights and lengths shown are for average male specimens of the various subspecies of each species: females tend to be slightly smaller. Please remember that new subspecies, or even new species (see the Iriomote cat), may be discovered at any time. When taking the domestic cat as a species we intentionally chose to use the typical feral cat a a model -- one that has returned to the wild state. Because of random interbreeding among feral domestic breeds, the dominance of certain genes, and the non-survival characteristic of certain traits, there has come to be established a definite and distinctive species: the medium sized brown or red mackerel tabby shorthair.

When discussing the subspecies (breeds) of the domestic cat taken as a species, it is important to remember that several new breeds are created each year, several breeds are discontinued each year, and there is no agreement among "experts" as to what defines a new breed, making the exact number of breeds impossible to compute. As an example of this disagreement, a blue (gray) British Shorthair is usually classed as a separate breed, the British Blue, but a black British Shorthair is not. Overall, there is a definite upward trend in the number of cat flavors.