Lagomorphs - Families Of Lagomorphs, Rabbits And Hares Of North America, The American Pika, Economic Importance

Lagomorphs are herbivorous mammals such as rabbits, hares, and pikas, in the order Lagomorpha. Because they exploit similar ecological niches, lagomorphs and rodents (order Rodentia) are rather similar in many aspects of their morphology and behavior. However, these orders are also different in important respects, and each represents an ancient evolutionary lineage.

One distinguishing feature of the lagomorphs is the two pairs of upper incisor teeth, one set being relatively small and located behind the larger pair. These incisors grow throughout the life of lagomorphs, and are completely covered with enamel; the larger pair has rather deep, vertical grooves. The incisors are used for clipping vegetation, and they are separated from the high-crowned cheek teeth, used for grinding food, by a rather wide gap, technically known as a diastema.

In addition, lagomorphs have five toes on the forefeet and four on the hind, dense, short fur, covering a thin, fragile skin that tears rather easily. The tail of these animals is short or absent. All lagomorphs are herbivores. Their major food is succulent leaves and herbaceous stems of a wide range of plant species. However, twigs and buds are also eaten, especially by northern species during the winter. Lagomorphs have a specialized enlarged portion of the large intestine known as the caecum, which acts as a fermentation chamber for the digestion of the cellulose in their bulky food of herbage and woody shoots.