Nutria belong to the rodent family known as Myocastoridae, which primarily inhabits South America.
On the other hand, guinea pigs belong to the Caviidae family, another group of rodents primarily found in South America.
While guinea pigs may seem superficially similar to nutria due to their rodent characteristics, including small, rounded bodies, sharp incisors, and herbivorous diets, they do not fall under the same phylogenetic classification.