title: A New Dicynodont (Therapsida: Anomodontia) from the Permian of Southern Brazil and Its Implications for Bidentalian Origins.
abstract: Dicynodonts were a highly successful group of herbivorous therapsids that inhabited terrestrial ecosystems from the Middle Permian through the end of the Triassic periods. Permian dicynodonts are extremely abundant in African deposits, but are comparatively poorly known from the other regions of Gondwana. Here we describe a new South American dicynodont, Rastodon procurvidens gen. et sp. nov., from the Boqueirão farm site of the Rio do Rasto Formation, Paraná Basin, Guadalupian/Lopingian of Brazil. Diagnostic features of R. procurvidens include uniquely anteriorly-curved maxillary tusks, well-developed ridges extending from the crista oesophagea anteriorly along the pterygoid rami, strong posterior angulation of the posterior pterygoid rami, and a bulbous, well-developed retroarticular process of the articular. Phylogenetic analysis indicates that R. procurvidens is the earliest and most basal member of Bidentalia, a cosmopolitan clade that includes Permian and Triassic dicynodonts whose dentition is usually reduced to a pair of maxillary tusks.
authors.affiliation: Instituto de Geociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.|Departamento de Ciências Naturais, Fundação Universidade Regional de Blumenau, Blumenau, Santa Catarina, Brazil.
authors.forename: Alessandra D S
authors.initials: AD
authors.lastname: Boos
authors.affiliation: Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Berlin, Germany.
authors.forename: Christian F
authors.initials: CF
authors.lastname: Kammerer
authors.affiliation: Instituto de Geociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Cesar L
authors.initials: CL
authors.lastname: Schultz
authors.affiliation: Instituto de Geociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Marina B
authors.initials: MB
authors.lastname: Soares
authors.affiliation: Instituto de Geociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Ana L R
authors.initials: AL
authors.lastname: Ilha
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001938:Brazil; D005580:Fossils; D008322:Mammals / Q000033:anatomy & histology* / Q000145:classification*