Known only to exist because of two fossils, the Chinchilla rat was recently seen alive and kicking near the Machu Picchu ruins Roberto Quispe

A cat-sized rat, which has only been seen as fossilised remains, has been found alive and well.

Believed to be extinct, the Chinchilla rat was discovered near an archaeological site near the Machu Picchu ruins, in Peru.

Previously, the only evidence for the massive rat existing was two skulls, which were discovered in 400-year-old Incan pottery. Dug up in 1912, the unusual skulls were believed to belong to a species that was extinct, reports Mongabay.

But in 2009 a park ranger, Roberto Quispe, reported sighting and treating a live arboreal Chinchilla rat near the original Machu Picchu archaeological site.

However, not knowing the mammal's significance, he released it back into the wild. A field study was later undertaken to find the rat.

The team of Mexican and Peruvian experts from the Instituto de Ecología of the Universidad Nacional Autónoma, in Mexico recently found a live sample of the Chincilla rat (Cuscomys oblativa) during the study, but also discovered seven new species.

According to the IUCN Red List, the species was believed to be extinct because no previous ecological surveys had discovered it, and only two skulls dating back to the 1500s proved they had ever existed.