Sika deerAll animals that have hooves are placed in a single order that is called the Ungulates. This is a Greek word, which means 'with hooves'. The Ungulates is a large order, and contains over 200 different species of hoofed animal. There are two main types of Ungulate. Those animals that have a hoof made up of a single toe, such as the horses and rhinos, are called Perrisodactyls. Perrisodactyl means 'odd toed'. Those ungulates which have hooves made up of two toes are called Artiodactyl. This means 'even toed'. There are a large number of Artiodactyl species, and including the sheep, goats, antelope, cattle and deer.

Within the Ungulate order of animals species are grouped together into separate families, all the species in a certain family are similar to each other or share a specific characteristic or feature. The Deer belong to the Cervidae family of ungulates. The one feature that unites all the members of the deer family is the possession of antlers. All deer species, except for the Chinese Water Deer, have antlers. The Chinese Water Deer is thought to have once had antlers but to have lost them through their evolutionary history. Deer also share a number of other characteristics such as having a relatively advanced form of rumination, and having long legs that are specially adapted to fast running and which contain a cannon bone.

reeves' muntjacThere are two separate lines of evolution within the Deer or Cervidae family. One group of deer evolved in North America, while the other groups centre of evolution was in Asia. The difference between these two groups of deer can be seen in the metacarpal bones of the remnant 2nd and 5th toes of the foot. The deer that evolved in North America are called the Telenmetacarpalia or New World Deer. While those that evolved in Asia are called the Plesiometacarpalia or the Old World Deer. Although they evolved in these separate parts of the world, some species from both groups have spread into different parts of the world, so that for example although the Red Deer is an Old World Deer it is now also found in America. There are 4 subfamilies of deer, and the Odocoilinae are Telenmetacarpalia or New World Deer, and the Muntiacinae, Hydropotinae and the Cervinae are Plesiometacarpalia or the Old World Deer.

MuntjacThe species within the Muntiacinae and the Hydropotinae subfamilies are all very similar to each other. These deer all have small rounded bodies and short thin legs. The antlers of the males are usually only short simple spikes, and the males often have well developed canine teeth that look like fangs. The Cervinae subfamily co contains deer that are medium sized with long slender legs and long thin bodies. The antlers are often comely and branching in the males. The Odocoilinae is the most diverse subfamily of deer, with their being a great range of shapes and sizes of deer species. For example the elk is the largest of all deer and lives on the open plains of the northern tundra, while the small Southern Pudu is the smallest species of deer and lives amongst the forests of mountainsides.

Altogether there are roughly about 40 species of deer. Biologists do not always agree about counts as a species or as a subspecies. For example some biologists consider the Persian Fallow Deer to be a subspecies of the Fallow Deer while others say it is a separate species. The same applies to the Roe deer and the Siberian Roe Deer. Here the most widely used list is shown.

Family : Cervidae

Subfamily Hydropotinae
Chinese Water Deer Hydroptes inermis

Subfamily Muntiacine
Bornean Yellow Muntjac Muntiacus atherodes
Black Muntjac Muntiacus crinifrons
Fea's Muntjac Muntiacus feae
Gong Shan Muntjac Muntiacus gongshanensis
Indian Muntjac Muntiacus muntjac
Leaf Muntjac Muntiacus putaoensis
Reeves' Muntjac Muntiacus reevesi
Truong Son Muntjac Muntiacus trungsonensis
Giant Muntjac Muntiacus vuquangensis
Tufted Deer Elaphodus cephalophus

Subfamily Cervinae
Thorold's Deer Cervus albirostris
Visayan Spotted Deer Cervus alfredi
Barasingha Cervus duvaucelii
Red Deer Cervus elaphus
Thamin Cervus eldii
Philippine Brown Deer Cervus mariannus
Sika Deer Cervus nippon
Schomburgk's Deer Cervus schomburgki (extinct)
Rusa Cervus timorensis
Sambar Cervus unicolor
Chital Axis axis
Calamian Deer Axis calamianensis
Bawean Deer Axis kuhlii
Hog Deer Axis porcinus
Père David's Deer Elaphurus davidianus
Fallow Deer Dama dama
Mesopotanian Fallow Deer Dama mesopotamica

Subfamily Odocoilinae
Roe Deer Capreolus capreolus
Siberian Roe Deer Capreolus pygargus
Moose (Elk) Alces alces
Mule Deer Odocoileus hemionus
White-tailed Deer Odocoileus virginianus
Pampas Deer Ozotoceros bezoarticus
Red Brocket Mazama americana
Merioa Brocket Mazama bricenii
Dwarf Brocket Mazama chunyi
Grey Brocket Mazama gouazoupira
Pygmy Brocket Mazama nana
Yucatan Brown Brocket Mazama pandora
Little Red Brocket Mazama rufina
Northern Pudu Pudu mephistophiles
Southern Pudu Pudu pudu
Marsh Deer Blastocerus dichotomus
Peruvian Guemal Hippocamelus antisensis
Chilean Guemal Hippocamelus bisulcus
Caribou/ Reindeer Rangifer tarandus