Zoology Taxonomy Tutorial

Within the kingdom Animalia, sometimes called Metazoa, you can find dozens of phyla, including Annelida, or segmented worms; Mollusca (molluscs); and Chordata (animals with dorsal nerve cords).

Classes, inside phyla, begin to feel intuitive to any observer of animals. Annelida includes Clitellata (worms with round egg sacs) and Polychaetes (hairy worms), among others. Mollusca contains such classes as Bivalvia (bivalve molluscs), Cephalopoda (squid, octopus and others) and Gastropoda (snails). Classes within Chordata include Agnatha (jawless fish), Reptilia (reptiles) and Mammalia (mammals).

Things become even more intuitive with orders. Class Mammalia has such orders as Cetacea (whales and dolphins), Perissodactyla (odd-toed hoofed animals) and Lagomorpha (rabbits, hares, and pikas). Note that the order Rodentia (rodents) does not include rabbits. Class Cephalopoda includes the orders Teuthida (squids) and Octopoda (octopuses).

Within orders, you will find families. The family Octopodidae within order Octopoda contains all the standard bottom-dwelling octopuses. The sister-family Argonautidae holds the paper nautiluses. Strange deep-water octopuses you may have seen on nature shows belong to other Octopoda families.

In the mammals, you get a broader breakdown. Order Perissodactyla includes the families Equidae (horses, donkeys, zebras), Tapiridae (tapirs) and Rhinocerotidae (rhinos). Rodentia contains many families, including the familiar forms of Erethizontidae (New World porcupines), Caviidae (guinea pigs and capybaras) and Castoridae (beavers). The order Primates includes the familes Cercopithecidae (Old World monkeys) and Hominidae (great apes).

The genus level is what most of us perceive in the world around us. We see a mouse of genus Mus, and we don't usually care if it is the species musculus (house mouse) or famulus (servant mouse). If bitten by a toxic blue-ringed octopus, a swimmer doesn't care whether it was a greater blue-ringed octopus (Hapalochlaena lunulata) or a lesser blue-ringed octopus (Hapalochlaena maculosa). People see chimps, the genus Pan, and don't often differentiate between Pan troglodytes (chimpanzee) and the smaller Pan paniscus (bonobo chimpanzee). That's not always the case, however. No one will confuse Equus grevyi (Grevy's zebra) with Equus ferus (domestic and wild horses) or Homo sapiens (modern human) with Homo habilis (a smaller, less brainy prehistoric man).