Explaining the Taxonomic Classification System

Taxonomy is the science of classification that is used to place organisms, both extant (currently living in the world) and extinct (no longer living in the world) in a hierarchical structure of association. To determine how closely related they are to each other. Taxonomic classification is not as clear as one might think it should be. Above the basic groups there may be a ‘super’ group and below may be’ sub’ and ‘infra’ groups. Nor does there appear to be a consensus on how they should be organized, with taxonomists frequently debating classifications, predominantly when determining whether a population of organisms should be classified as a separate species or as a sub-species.

The easiest way to elucidate the system is by example, the following is an example of taxonomic nomenclature (naming) used to classify the animal known by the common names De Brazza’s monkey, De Brazza’s guenon, Schlegal’s guenon or Neglectus monkey. As this species is native to central Africa it might be more appropriate to call them Kalasinga, their name in Swahili.

The following is a compilation put together based on information gleaned from several sources and my own opinion where there have been conflicting structures, said reference sources are listed after the classification. There are two top level classifications currently in use, the originally used Kingdom, which in this case is Animalia and the more recently created Domain, which would be Eukaryota for the Kalasinga. Below these we have:

Phylum is Chordata; characterized by:
* The notochord, from which the phylum takes its name.
* A dorsal, tubular nerve cord.
* Pharyngeal gill slits, often only appearing briefly during a developmental stage for many animals in this phylum.
* A postanal tail; even Homo sapiens sapiens (ourselves) have a vestigial one.

Subphylum is Vertebrata; characterized by:
* A spinal column of vertebrae virtually replacing the notochord.
* A brain case or cranium.

Superclass is Gnathostomata; characterized by:
* A jaw.

Class is Mammalia, Linnaeus, 1758; characterized by:
* Hairs.
* Mammary glands.
* A highly developed nervous system.

Subclass is Theria, Parker & Haswell, 1897; characterized by:
* Their specialized tooth structure, particularly the molars.
* Giving birth to live young, without a shelled egg.
* External ears.
* Ability to suckle, so young can ingest milk from their mother.

Infraclass is Eutheria, Gill, 1872; characterized by:
* The young developing in the female attached to a well-formed placenta over a relatively long gestation period.
* The young when born are at a comparatively advanced stage of development.

Order is Primates L.; characterized by:
* Opposable pollex and hallux, first digits on fore and hind limbs respectively, creating a grasping hand’.
* Unfused and highly mobile radius and ulna in the forelimb and tibia and fibula in the hind, evolved for an arboreal lifestyle.
* Fingernails.
* A large brain.
* A reduced sense of smell.
* Stereoscopic vision.

Suborder is Anthropoidea; characterized by:
* Being primarily diurnal.
* Having a relatively flat face at least partially devoid of fur.
* Well developed stereoscopic vision.
* The ability to sit on their haunches and use their hands.
* An unusually large brain.
* A globe-shaped brain-case.

Infraorder is Catarrhini; characterized by:
* Downward pointing nostrils in a narrower nose.
* Only 2 premolar teeth.

Up until now the De Brazza’s monkey is taxonomically identical to us, from here it differentiates.

Superfamily is Cercopithecoidea; characterized by:
* Being quadrupeds that sit upright on hardened skin pads called ischial callosities on their buttocks, often also used to display sexual readiness.
* Having a transverse ridge formed where the cusps of their molars have fused.

Family is Cercopithecidae, Gray, 1821 (Old World Monkeys); characterized by:
* A tail that is not prehensile and may be vestigial.
* A long concave palate.
* Having terrestrial as well as arboreal species.

Subfamily is Cercopithecinae, Gray, 1821; characterized by:
* Being omnivorous.
* Cheek pouches.
* Simple stomachs.

Genus is Cercopithecus L.; characterized by:
* Long legs.
* A long tail.
* Being located geographically, throughout sub-Saharan Africa.

Species is Cercopithecus neglectus, Schlegel, 1876; characterized by:
* A gray body with black extremities.
* A round head with a white muzzle and beard and an orange crown.
* Sexual dimorphism, the males weigh up to 7kg in comparison to the females 4kg average.
* The males scrotum is blue.
* Being both arboreal and terrestrial.
* Having the most robust feet of the guenons.


Integrated Taxonomic Information System


Proceedings of the National Academy of Sciences of the United States of America

Hickman Jr, C.P. & Roberts, L.S. (1994) Biology Of Animals, 6th Ed, Wm.C.Brown Publishers

Dorit, R.L., Walker Jr, W.F. & Barnes, R.D. (1991) Zoology International Ed, Saunders College Publishing