title: New stem-sauropodomorph (Dinosauria, Saurischia) from the Triassic of Brazil.
abstract: Post-Triassic theropod, sauropodomorph, and ornithischian dinosaurs are readily recognized based on the set of traits that typically characterize each of these groups. On the contrary, most of the early members of those lineages lack such specializations, but share a range of generalized traits also seen in more basal dinosauromorphs. Here, we report on a new Late Triassic dinosaur from the Santa Maria Formation of Rio Grande do Sul, southern Brazil. The specimen comprises the disarticulated partial skeleton of a single individual, including most of the skull bones. Based on four phylogenetic analyses, the new dinosaur fits consistently on the sauropodomorph stem, but lacks several typical features of sauropodomorphs, showing dinosaur plesiomorphies together with some neotheropod traits. This is not an exception among basal dinosaurs, the early radiation of which is characterized by a mosaic pattern of character acquisition, resulting in the uncertain phylogenetic placement of various early members of the group.
authors.affiliation: Museu de Ciências Naturais, Universidade Luterana do Brasil (ULBRA), Av. Farroupilha 8001, 92425-900, Canoas, Rio Grande do Sul, Brazil.
authors.forename: Sergio F
authors.initials: SF
authors.lastname: Cabreira
authors.forename: Cesar L
authors.initials: CL
authors.lastname: Schultz
authors.forename: Jonathas S
authors.initials: JS
authors.lastname: Bittencourt
authors.forename: Marina B
authors.initials: MB
authors.lastname: Soares
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Fortier
authors.forename: Lúcio R
authors.initials: LR
authors.lastname: Silva
authors.forename: Max C
authors.initials: MC
authors.lastname: Langer
mesh_terms: D000818:Animals; D001938:Brazil; D025061:Dinosaurs / Q000033:anatomy & histology* / Q000145:classification*; D005580:Fossils; D010802:Phylogeny; D012886:Skull / Q000033:anatomy & histology
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