Guiomys is an extinct genus of cavioid rodent which existed in west central Patagonia of Argentina, during the middle Miocene. Guiomys is known from mandibular and maxillary fragments with molars, and isolated cheek teeth. It was first named by María E. Pérez in 2010 and the type species is Guiomys unica.
Species taxanomy provided by GBIF Secretariat (2022). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org on 2023-06-13; License: CC BY 4.0