Incamys

Incamys is an extinct genus of chinchillid rodent that lived during the Late Oligocene (Deseadan) in what is now South America. Fossils of this genus have been found in the Salla Formation of Bolivia and the Agua de la Piedra and Sarmiento Formations of Argentina. Research on endocasts suggest their were group living using call communication like modern chinchillas.

Taxonomy
Incamys was first described by Hoffstetter and Lavocat, based on remains found in the Salla Formation of Bolivia, with the proposed type species being Incamys bolivianus, referring to the country it was found in. Later, in 1976, a new species was named, I. pretiosus, which was subsequently found to be a junior synonym of the type species. In 2015, Vucetich and colleagues described a new species of Incamys, I. menniorum, from the Sarmiento Formation of Chubut Province, Argentina.

The following cladogram of the Caviomorpha is based on Busker et al. 2020, showing the position of Incamys.

Brain Endocast Research
Research on 30 million year old Incamys bolivianus virtual endocasts show they had expanded temporal lobes in the cerebrum and large caudal colliculi in the midbrain, arguing they had enhanced auditory acuity and vocalization. This is consistent with them living in social groups and using calls to communicate with each other, similar to modern chinchillas.