2011/02/16 by Andrés Rinderknecht, Enrique Bostelmann T., Martı́n Ubilla · 29 citations
Earth and Planetary Sciences · Environmental Science · Agricultural and Biological Sciences · #Evolution and Paleontology Studies #Fish biology, ecology, and behavior #Bat Biology and Ecology Studies #Skull #Anatomy #Meatus #Paleontology #Genus #Late Miocene #Geology #Biology #Zoology
paper · pdf · doi:10.1644/10-mamm-a-099.1
published in Journal of Mammalogy 92(1), 169-178 (Oxford University Press)
openalex publication_date 2011/02/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/23
In this contribution we describe the fossil remains of a new genus and species of a giant rodent, Arazamys castiglionii (Mammalia, Rodentia, Dinomyidae), from Arazatí beach in San José Department, southern Uruguay. The specimen was exhumed from pelitic sediments of the Camacho Formation, biostratigraphically assigned to the late Miocene Huayquerian South American Land Mammal Age. The remains include an incomplete skull (braincase, auditory region, and nearly full dentition) and the atlas. Based on comparative studies of the anatomy of the auditory region, we describe 2 morphologies for the subfamily Eumegamyinae, 1 characterized by a short meatus acusticus externus, a great development of the foramen stylomastoideum, and a conspicuous ectotympanic cavity, and a 2nd characterized by a long meatus acusticus externus and lack of the ectotympanic fossa. The potential taxonomic and systematic value of the auditory region in Dinomyidae is discussed.