The
order Rodentia, the "gnawing" mammals, contains over
40% of all species in the class Mammalia. A consistent diagnostic
character for all rodents is an upper and lower pair of arc-shaped
chisel-edged incisors. Rodents have adapted to most habitats
and include terrestrial, fossorial, saltatorial, arboreal, gliding,
and semiaquatic forms. They range in size from the smallest
mice, weighing only a few grams, up to the largest living rodent,
the capybara, weighing up to 50 kilograms. Most rodents are
primarily omnivorous, feeding on bark, grass, seeds, other vegetation,
insects and other animal matter. With a few exceptions, an external
tail is present, but its form and length vary greatly. Rodents
are well haired over most of their body. Most are quadrupedal,
but some arid-land species have greatly enlarged hind limbs,
and are capable of ricochetal locomotion. The distribution of
rodents is almost worldwide. They are native to most land areas
except some Arctic and oceanic islands, New Zealand and Antarctica.
SUBORDER
SCIUROMORPHA
Family Aplodontiidae
Family
Sciuridae
Subfamily Sciurinae
Tribe Sciurini
Tribe
Pteromyini