Discovery Science: Earth Mammals – Rodents and Lagomorphs

Earth Science: Mammals – Rodents and Lagomorphs

Although they can appear similar, rodents and lagomorphs developed independently of one another. They can be easily distinguished by the different incisor teeth on their upper jaw.

Rodents and lagomorphs inhabit the entire planet with the exception of Antarctica. Rodents mostly feed on leaves, seeds, fruits, roots, and tubers; a few also feed on insects or other invertebrates. Their teeth are supported by strong chewing muscles, which also give them their chubby-faced appearance.

Many rodents—including mar- mots and house mice—live sociably in groups. Active at all times, they can be found in habitats ranging from water to high mountain tops. The synanthropic species, such as the house mouse, have adapted their habits to human environments.

Beavers and South American capybaras inhabit wetlands and are good swimmers. The African spring hare is an outstanding jumper due to its kangaroo-like hind legs. Squirrels’ tails help them balance when they climb.

The lagomorphs include both long-eared animals, such as hares and rabbits, and small-eared animals, such as the North American pika. Most lagomorphs have split upper lips and skin folds (harelips) and, when they open and shut their nostrils, their faces twitch. Their touch and hearing are well developed and aided by sensory hairs around their noses and ears.

Their long, hair-covered hind legs enable them to run quickly— hares can achieve speeds of up to 50 miles per hour (80 km/h), helping them escape from predators. Their favored habitats are open fields, grasslands, plateaus, and semideserts. Lagomorphs are plant-eaters. To help them digest plant cellulose, they often excrete soft feces pellets that they then ingest a second time.

Their young are raised in burrows or nests. Due to their short lifespan, lagomorphs have several litters of about nine each year. This high birth frequency compensates for the fragility of the young, which are often devoured by predatory animals and birds. The fur of wild hares and similar animals is almost always reddish or gray-brown for maximum camouflage.


Porcupines have long spines, which are actually adapted hairs, it raises its spines to defend itself. the animal is threatened, Rodents and lagomorphs can be distinguished by their teeth. Rodents have a pair of chisel-like incisors at the front of their upper and lower

These teeth grow continuously and the chisel shape is formed through constant wear. Behind the incisors is a distinctive gap before the molars further back in the jaw. In contrast, all lagomorphs have two pairs of small “peg-teeth that sit behind the large incisors on the
upper jaw.

Because of this, lagomorphs are well adapted for a gnawing diet.