Earth Science: Biology – Animals – Ungulates
Ungulates are hoofed mammals that have phalanges, or toes, that are encased within a hard covering. Ungulates include horses, cattle, sheep, goats, and many other animals, and almost all are herbivores.
Ungulates include the largest, most impressive, and most commonly found land mammals. They can be identified by their toes (phalanges) that are covered by hooves. Except for the omnivorous pigs and the insect-eating anteater, all ungulates are plant-eaters. The group includes such domesticated animals as horses, cattle, sheep, goats, and pigs.
Wild ungulates include elephants, rhinos, giraffes, and the sea cow, an ungulate that has returned to the water. Originally, ungulates were found on all the continents of the Earth except Australia.
Although they are vegetarians, ungulates cannot di- gest plants on their own as they lack the enzyme that ensures the complete digestion of cellulose. Thus, these animals require the presence of symbiotic bacteria, yeasts, and protozoa in their digestive systems.
Many ungulates, including deer and cattle, are ruminants. Ruminants improve their breakdown of cellulose by repeatedly chewing predigested cuds.
Most hoofed animals have long legs that helped them flee from predators in their original grassland and savanna habitats. Some ungulates (often males but some females, too) have developed other attributes such as horns (on cattle, for example), antlers (deer), or tusks (pigs).
Rather than use these aggressively, hoofed animals usually use these features to intimidate and assess the strength of their opponents. Hoofed animals are classified within two broad groups: the even-toed and the odd-toed. The even-toed ungulates include giraffes and hippos, whereas the odd-toed encompass the horses, rhinos, and tapirs.
During their existence, all ungulates have slowly reduced their number of phalanges, so that in the case of modern horses there is only one hoof (toe) per leg.
ANTLERS
Male deer use their antlers for fighting rivals. Every year, they grow a set of horns from two points on the forehead called pedicles. During their growth, the bony parts are covered by a thick skin (velvet) with short hair, which supplies nutrients.
At the beginning of the rut, male deer rub off the velvet on strong tree branches. During the fall or winter, a thin layer of bone between the antlers and pedicles dissolves and the deer shed their antlers.
BASICS
DOMESTICATION first developed when early people began to farm. Hoofed animals were bred as trans-port and draft animals, as well as readily available sources of milk, wool, and meat.