Josephoartigasia Monesi: Unknown Species Of South America.

Time period: middle Pliocene, early Pleistocene of 4 to 2 million years ago. Location: South America

Josephoartigasia monesi, an unknown species of South American caviomorph rodent, is the largest rodent known and lived maximum 4 to 2 million years ago when the Pliocene to early Pleistocene. 

The species may have weighed 1,000 kg, considerably larger than its closest living relative, the pacarana. The rodent may become lived in an estuarine environment or a delta system with the forest communities and may have eaten soft, and the remaining incisor is more than 30 cm in length.

The total estimated body length is 3 m, with a height of 1.5 m. By comparing the skull with various extant species or rodents, the authors of the original paper estimated a mass between 468 kg and 2,586 kg, with a median estimate of 350 kg to 1,534 kg, with a median of 900 kg. 

There is no dispute that J. monesi replaces Phobeomys Patterson, a related and somewhat older species that lived in Venezuela during the Late Miocene, ass the largest rodent. However, size comparisons are difficult because previous was based on forelimb and hindlimb elements, which are not present in the J. monesi specimen.