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
- Dentition:
- 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.