Lagomorph

Lagomorphs are an order of mammals comprising two living families: Leporidae, which includes rabbits and hares, and Ochotonidae, the pikas. They are found across much of the Northern Hemisphere and in parts of Africa and Asia, occupying a range of habitats from grasslands and woodlands to deserts and alpine regions. They generally avoid dense tropical forests and extreme polar zones.

A characteristic feature of lagomorphs is their dentition. In each half of the upper jaw they have two incisors, and a small second pair of peg-like incisors located behind the primary incisors in many species, along with a separate pair in the lower jaw. They lack canines and have a diastema between the incisors and the cheek teeth. Their incisors and cheek teeth are specialized for gnawing and processing plant material. Lagomorphs are herbivores with a large caecum and rely on hindgut fermentation; many species engage in coprophagy, re-ingesting soft feces to recover nutrients.

Reproduction and behavior vary among the families. Rabbits (Leporidae) commonly live in social burrow systems and give birth to altricial young in nests. Hares are usually more solitary and give birth to precocial young in open nests. Pikas (Ochotonidae) are small, stout herbivores of rocky habitats, often forming family groups and collecting vegetation to stockpile as winter hay.

Fossil evidence places lagomorphs in the early Cenozoic, with diversification in the Northern Hemisphere. They are part of the superorder Glires, closely related to rodents, though they form a distinct order.