Armored rat

The armored rat (Hoplomys gymnurus) is a species of rodent in the family Echimyidae. It is monotypic within the genus Hoplomys. It is found in Latin America, from northern Honduras to northwest Ecuador. It possesses a range of spines on its back and sides of the body.

Description
Adults weigh between 218 - 790 g with males weighing more on average than females. They are born with soft fur, and the spines begin growing after the first month. The thick spines on the back and sides measure up to 33 mm and 2 mm in diameter. The head and body measures between 220 - 320 mm in length, with the tail adding another 150 - 255 mm. The color of the armored rat range from black to reddish brown, and has a pure white underside. They are similar in appearance to Tome's spiny-rat, but the eyes of the armored rat are smaller and they have a longer snout. Its diet includes fruit, insects and green plant matter. The normal litter size is one to three.

Habitat
The armored rat is a nocturnal species, which occupies burrows. These burrows are usually positioned in steep banks close to a water source, and can measure up to 2 m in length before reaching a nesting chamber. They are distributed from northern Honduras to northwest Ecuador, from lowlands up to around 800 m in altitude, including Panama's isolated Caribbean island of Isla Escudo de Veraguas.

Etymology

 * The genus name Hoplomys derives from the two Ancient Greek words, meaning "armor", and  , meaning "rat".
 * The species name gymnurus derives from the two Ancient Greek words, meaning "naked", and  , meaning "tail".

Phylogeny
Part of the infraorder Hystricognathi and family Echimyidae, armored rats are more closely related to porcupines, Guinea pigs, chinchillas, and common degus than to the common brown rat.

Within Echimyidae, the genus Hoplomys is the sister group to the genus Proechimys. In turn, these two taxa share evolutionary affinities with other Myocastorini genera: Callistomys (painted tree-rats) and Myocastor (coypus or nutrias) on the one hand, and Thrichomys on the other hand.