Ungulates

Ungulates are mammals characterized by the presence of hooves, a term that encompasses a large and diverse group of species. Traditionally they are divided into two main groups: Perissodactyla, the odd-toed ungulates (horses, donkeys, zebras, tapirs, rhinoceroses), and Artiodactyla, the even-toed ungulates (cattle, sheep, goats, deer, antelopes, camels, giraffes, hippos, and many others). In modern classifications, whales and cetaceans are placed within Cetartiodactyla, reflecting their close relationship to even-toed hoofed mammals.

Ungulates range from small to very large and generally possess keratinous hooves that aid in running and support. Diets are primarily herbivorous, with grazing or browsing on grasses and foliage; a few species exhibit omnivory, such as pigs. Digestive strategies vary: many artiodactyls are ruminants, with four-chambered stomachs that ferment plant material before digestion; others, including horses and some rhinos, are hindgut fermenters, relying on microbial digestion primarily in the cecum and colon.

Ecology and human use: Ungulates occupy varied habitats worldwide and often form large herds. They play key roles as primary herbivores, prey for predators, and in shaping vegetation. Domestication of cattle, sheep, goats, and pigs has had profound economic and cultural impact, providing meat, milk, hides, leather, and draft power.

Evolution and classification: The ungulate concept is functional rather than a strict clade; molecular studies have refined their relationships but the term remains widely used in biology and conservation. The fossil record shows ungulates appearing in the Paleocene–Eocene, with major diversification in the Miocene and Pliocene.