Lagomorpha

This chapter includes members of the order Lagomorpha, including family groups of Leporidae (rabbits and hares) and Ochotonidae (pikas). Notable characteristics of the Lagomorpha order include four maxillary incisors, a gastrointestinal tract that supports hindgut fermentation of a completely herbivorous diet, and smooth cerebral surfaces (lissencephaly). Ochotonidae (pikas) are the smaller family relative to Leporidae. Lagomorphs are widespread around the world, with the only continental exception being Antarctica. The thoracic cavity is a relatively small proportion of the torso in lagomorphs compared with other non-hindgut fermenting small mammals. The abdomen comprises a large proportion of the torso, as rabbits are monogastric hindgut fermenters with a large cecum that comprises approximately 40–50% of their gastrointestinal tract. Sexual maturity occurs at four to six months in smaller lagomorphs and up to five to eight months in larger lagomorphs.