#pacarana

Giant pacarana (Josephoartigasia monesi)

Josephoartigasia is an extinct genus of enormous rodent from the Early Pliocene to Early Pleistocene of Uruguay.

The skull of J. monesi measures 53 cm, similar to a beef cow skull, equating to a full body length of 262.8 cm—though this is likely an overestimate—and a weight of about 480–500 kg. This makes J. monesi the biggest rodent ever discovered. Its skull was heavily reinforced to withstand high stresses far exceeding what bite force alone could exert, so it could have been using its teeth to crack nuts, excavate large burrows, dig up roots, or self defense against predators.

Josephoartigasia lived in a forested estuarine environment. Like other giant extinct rodents, it predominantly ate leaves or fruits, though the extreme bite force of J. monesi would have permitted it to consume a wide variety of different plants if necessary.

Pacarana is the closest living relative of Josephoartigasia.

Pacarana (Dinomys branickii)

Pacarana is large for a rodent, weighing up to 15 kg and measuring up to 79 cm in length, not including the thick, furry tail. It has a relatively large head with small ears and a thick neck. The fur is coarse black or brown with two white stripes grading to spots along the back and on the sides.

Pacaranas have a herbivorous diet that includes fruits, leaves, and plant shoots. They are social animals and usually live in family groups of 4 or 5 individuals. They are nocturnal and during the day they rest in caves between rocks or dens at the base of trees. Pacaranas spend most of their time on the ground, however, they are very adept climbers. They communicate with each other using various sounds, whines, songs, hisses, and tooth chattering.