2022/03/01 by Luciano L. Rasia · 1 citation
Earth and Planetary Sciences · Agricultural and Biological Sciences · Environmental Science · #Evolution and Paleontology Studies #Bat Biology and Ecology Studies #Animal Ecology and Behavior Studies
paper · doi:10.1080/08912963.2022.2042810
openalex publication_date 2022/03/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
Dinomyidae is a family of rodents including one extant species, Dinomys branickii, but with a high past diversity. Gyriabrus is a large dinomyid with euhypsodont cheek teeth and an occlusal pattern that changes throughout the ontogeny of the animal. Eight species of Gyriabrus have been described in the late Miocene to Pliocene of Argentina, Uruguay, Colombia and Brazil. The taxonomic status of Gyriabrus has been questioned, being considered as juvenile forms of other euhypsodont dinomyids. According to this study, Gyriabrus has a unique dental anatomy among euhypsodont dinomyids and is a valid genus. A study of the cheek teeth permitted to propose an ontogenetic series. All the species described from the late Miocene of Argentina (Ituzaingó Formation) and Uruguay (Camacho Formation) belong to Gyriabrus holmbergi (including G. glutinatus, G. rebagliattii, G. indivisus and G. teisseirei), representing different wear stages. ?Gyriabrus quadratus, G. latidens (late Pliocene? of Argentina) and ?G. royoi (late Miocene-Pliocene of Colombia), all based on isolated teeth, are considered as valid species, pending future findings that allow a deeper comparison. This study contributes to the knowledge of the systematics, taxonomy and anatomy of extinct Dinomyidae, which are essential for future studies of the evolutionary history of the group.