Primates
Fossil range: Latest Cretaceous - Recent |
||||||||||||||
Olive Baboon, an Old
World monkey |
||||||||||||||
Scientific classification |
||||||||||||||
|
||||||||||||||
Families |
||||||||||||||
|
A primate (L. prima,
first) is any member of the biological order Primates, the group that
contains all the species commonly related to the lemurs, monkeys, and apes,
with the latter category including humans.[1]
The English singular primate is a back-formation from the Latin name Primates,
which itself was the plural of the Latin primas ("one of the first,
excellent, noble"). Primates are found all over the world. Non-human
primates occur mostly in Central and South America, Africa, and southern Asia. A
few species exist as far north in the Americas as southern Mexico, and as far
north in Asia as northern Japan.
The Primates order is
divided informally into three main groupings: prosimians, monkeys of the New
World, and monkeys and apes of the Old World. The prosimians are species whose
bodies most closely resemble that of the early proto-primates. The most well
known of the prosimians, the lemurs, are located on the island of Madagascar
and to a lesser extent on the Comoros Islands, isolated from the rest of the
world. The New World monkeys include the familiar capuchin, howler, and squirrel
monkeys. They live exclusively in the Americas. Discounting humans, the rest of
the simians, the Old World monkeys and the apes, inhabit Africa and southern
and central Asia, although fossil evidence shows many species existed in Europe
as well.
All primates have five
fingers (pentadactyly), a generalized dental pattern, and a primitive
(unspecialized) body plan. Another distinguishing feature of primates is fingernails.
Opposing thumbs are also a characteristic primate feature, but are not limited
to this order; opossums, for example, also have opposing thumbs. In primates,
the combination of opposing thumbs, short fingernails (rather than claws) and
long, inward-closing fingers is a relic of the ancestral practice of gripping
branches, and has, in part, allowed some species to develop brachiation as a
significant means of transportation. Forward-facing color binocular vision was
also useful for the brachiating ancestors of humans, particularly for finding
and collecting food, although recent studies suggest it was more useful in
courtship. All primates, even those that lack the features typical of other
primates (like lorises), share eye orbit characteristics, such as a postorbital
bar, that distinguish them from other taxonomic orders.[citation needed]Old
World species (apes and some monkeys) tend to have significant sexual
dimorphism. This is characterized most in size difference, with males being up
to a bit more than twice as heavy as females. This dimorphism is a result of a polygynous
mating system where there is significant pressure to attract and defend
multiple mates. New World species form pair bonds, and so these species
(including tamarins and marmosets) generally do not show a significant size
difference between the sexes.
Primates evolved from arboreal
animals and many modern species live mostly in trees and hardly ever come to
the ground. Other species are partially terrestrial, such as baboons and the Patas
Monkey. Only a few species are fully terrestrial, such as the Gelada and Humans.
Primates live in a diverse number of forested habitats, including rain forests,
mangrove forests, and mountain forests to altitudes of over 3000 m. Although
most species are generally shy of water, a few are fine swimmers and are
comfortable in swamps and watery areas, including the Proboscis Monkey, De
Brazza's Monkey and Allen's Swamp Monkey, which even developed small webbing
between its fingers. Some primates, such the Rhesus Macaque and the Hanuman
Langur, are hemerophile species and cities and villages have become their
typical habitat.[2]
Wikipedia
http://en.wikipedia.org/w/index.php?title=Primate&action=history
http://www.gnu.org/copyleft/fdl.html