oddtoed

Odd-toed ungulates, or Perissodactyla, are an order of large, hoofed mammals characterized by an uneven number of toes and a limb axis that passes through the middle digit. Weight is borne primarily by the third toe, with other toes reduced or not used for locomotion in most species. This mesaxonic arrangement distinguishes them from the even-toed ungulates (Artiodactyla), which bear weight on two or four front digits.

The order today comprises three families: Equidae (horses, zebras, donkeys), Rhinocerotidae (rhinoceroses), and Tapiridae (tapirs). Extant species are adapted to varied habitats, from grasslands and savannas to tropical forests and wetlands. Equids are cursorial grazers with a single dominant toe; rhinos are large, often armored herbivores with three toes per foot; tapirs are medium-sized, with a flexible snout and forest-dwelling habits.

Perissodactyls are hindgut fermenters and generally non-ruminant herbivores; digestion relies on microbial fermentation in the hindgut. They originated in the early Paleogene and were more diverse in the past, with many extinct lineages.

Today, odd-toed ungulates are distributed mainly in Africa, Asia, and the Americas (tapirs in the Americas and Southeast Asia). Habitat loss and poaching have endangered several species, notably some rhinoceroses. Conservation efforts focus on habitat protection, anti-poaching, and breeding programs.