Taxonomic Hierarchies

The current taxonomic system that we use these days was thought up by Carl Linnaeus who loved to name everything in Latin. Here is a mnemonic to remember the taxonomic levels;

King Philip can order five great specimens

This stands for Kingdom Phylum Class Order Family Genus Species.

People also insert super-families, sub-orders, sub-families etc. for further classifications.

The taxonomy of the common chimp:

Kingdom Animalia
Phylum Chordata (things with backbones)
Class Mammalia
Order Primates
suborder Anthropoidea (prosimian would be the other option)
infraorder Catarrhini (old world monkeys)
superfamily Hominoidea (includes apes and humans)
Family Pongidea
Subfamily Ponginae
Genus Pan (chimps)
Species Troglodytes (common chimps)

To help in recognizing what level a taxonomic name is, remember this:

Superfamilies always end in -oidea
Families always end in -dae
Subfamilies always end in -nae

If two animals are of a different species, they won't interbreed naturally. In captivity, they're not always so picky. But anyway the species classification is based on a characteristic that's really in nature. The other levels of taxonomy are just for our convenience, and there's always lots of disagreement about how things should be classified.

People used to classify things together if they looked similar. Recently they've gotten better at reconstructing the tree of life. It has thus become more possible to group beings together because they have a common ancestor rather than because they look similar to a scientist. This is better cause it's based on fact, not on an opinion of how they look or behave. This is called a phyletic classification; to classify things by their real ancestors. Using this newer-type classification, we would divide the primates into two groups:
Strepsirrhines are the lemurs and the lorises.
Haplorrhines are the tarsiers, monkeys, apes, and humans.

But the traditional way of doing it is prosimians vs. anthropoids, based on how anthropoids all have similar adaptation developments. Prosimians are the Lemurs, Lorises, and Tarsiers in this classification. This traditional classification system is what we'll use since that's how our text divides things, but we should be aware that the scientific community will most likely be moving toward the phyletic classification system.

Characteristics that differentiate the prosimians from the anthropoids

Prosimians are pretty small relative to the Anthropoids. Anthropoids have fused skulls while the prosimians do not. The orbit (eye socket) is open in the prosimians, closed in anthropoids. Anthropoids have nails, while the prosimians have a grooming claw on the index finger of the hind foot. (The rest of the digits have nails.) The prosimians' teeth are also different; The incisors are almost horizontal in prosimians, and this is called the grooming comb because they use it to groom. Some species also use it for feeding; gouging into trees to get gum or insects.

...and the strepsirrhines from the haplorrhines

In strepsirrhines, the upper lip is divided, only attached inside. Strepsirrhines have a moist naked nose, unlike haplorrhines but like other mammals. Strepsirrhines' eyes have a reflecting tapetum like cats or deer. It is right behind retina and it makes the eyes more sensitive so that they're better at picking up low levels of light. Note that strepsirrhines are mostly nocturnal, so they need to be able to see in low light levels. Typical prosimian behavior patterns; nocturnal, insectivorous, solitary.

Lorises and galagos are in Africa and Asia
Lemurs are just on madagascar
Tarsiers are just in SE asia

Differences between Prosimians and Anthropoids: A Summary

Anthropoids have fused mandibles while prosimians' can move independently.

Brain size:
Anthropoids have larger brains relative to their body weight.

Nails vs. claws:
Anthropoids have nails vs. claws, with one exception.

Visual system:
Anthropoids have binocular and color vision. Prosimians don't have either one but they can smell better than anthropoids.

Body size:
Anthropoids tend to be larger.

Ecological diversity:
Anthropoids fill more niches than Prosimians- places which are drier, colder, sparser etc.
Anthropoids also exploit more food sources than Prosimians.
Anthropoids are all diurnal, with one exception.

The Anthropoids are divided into two infraorders. These represent two different lines of descent, which are also divided geographically:
Catarrhines are the new world monkeys.