title: A Unique Late Triassic Dinosauromorph Assemblage Reveals Dinosaur Ancestral Anatomy and Diet.
abstract: Dinosauromorpha includes dinosaurs and other much less diverse dinosaur precursors of Triassic age, such as lagerpetids [1]. Joint occurrences of these taxa with dinosaurs are rare but more common during the latest part of that period (Norian-Rhaetian, 228-201 million years ago [mya]) [2, 3]. In contrast, the new lagerpetid and saurischian dinosaur described here were unearthed from one of the oldest rock units with dinosaur fossils worldwide, the Carnian (237-228 mya) Santa Maria Formation of south Brazil [4], a record only matched in age by much more fragmentary remains from Argentina [5]. This is the first time nearly complete dinosaur and non-dinosaur dinosauromorph remains are found together in the same excavation, clearly showing that these animals were contemporaries since the first stages of dinosaur evolution. The new lagerpetid preserves the first skull, scapular and forelimb elements, plus associated vertebrae, known for the group, revealing how dinosaurs acquired several of their typical anatomical traits. Furthermore, a novel phylogenetic analysis shows the new dinosaur as the most basal Sauropodomorpha. Its plesiomorphic teeth, strictly adapted to faunivory, provide crucial data to infer the feeding behavior of the first dinosaurs.
authors.affiliation: Museu de Ciências Naturais, Universidade Luterana do Brasil, Canoas-RS 92425-900, Brazil.
authors.forename: Sergio Furtado
authors.initials: SF
authors.lastname: Cabreira
authors.affiliation: Departamento de Geologia e Paleontologia, Museu Nacional-UFRJ, Rio de Janeiro-RJ 20940-040, Brazil.
authors.forename: Alexander Wilhelm Armin
authors.initials: AWA
authors.lastname: Kellner
authors.affiliation: Centro de Apoio à Pesquisa Paleontológica, Universidade Federal de Santa Maria, Santa Maria-RS 97105-900, Brazil.
authors.forename: Sérgio
authors.initials: S
authors.lastname: Dias-da-Silva
authors.affiliation: Museu de Ciências Naturais, Universidade Luterana do Brasil, Canoas-RS 92425-900, Brazil; Centro de Apoio à Pesquisa Paleontológica, Universidade Federal de Santa Maria, Santa Maria-RS 97105-900, Brazil.
authors.forename: Lúcio
authors.initials: L
authors.lastname: Roberto da Silva
authors.affiliation: Ludwig-Maximilians-Universität and Bayerische Staatssammlung für Paläontologie und Geologie, Munich 80333, Germany.
authors.forename: Mario
authors.initials: M
authors.lastname: Bronzati
authors.affiliation: Laboratório de Paleontologia, FFCLRP, Universidade de São Paulo, Ribeirão Preto-SP 14040-901, Brazil; School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK.
authors.forename: Júlio Cesar de Almeida
authors.initials: JCA
authors.lastname: Marsola
authors.affiliation: Centro de Apoio à Pesquisa Paleontológica, Universidade Federal de Santa Maria, Santa Maria-RS 97105-900, Brazil.
authors.forename: Rodrigo Temp
authors.initials: RT
authors.lastname: Müller
authors.affiliation: Departamento de Geologia, Universidade Federal de Minas Gerais, Belo Horizonte-MG 31270-901, Brazil.
authors.forename: Jonathas de Souza
authors.initials: JS
authors.lastname: Bittencourt
authors.affiliation: Museu de Ciências Naturais, Universidade Luterana do Brasil, Canoas-RS 92425-900, Brazil.
authors.forename: Brunna Jul'Armando
authors.initials: BJ
authors.lastname: Batista
authors.affiliation: Instituto Federal de Educação Ciência e Tecnologia Catarinense, Concórdia-SC 89700-000, Brazil.
authors.forename: Tiago
authors.initials: T
authors.lastname: Raugust
authors.affiliation: Centro Universitário La Salle, Canoas-RS 92010-000, Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Carrilho
authors.affiliation: Centro Universitário La Salle, Canoas-RS 92010-000, Brazil.
authors.forename: André
authors.initials: A
authors.lastname: Brodt
authors.affiliation: Laboratório de Paleontologia, FFCLRP, Universidade de São Paulo, Ribeirão Preto-SP 14040-901, Brazil. Electronic address: mclanger@ffclrp.usp.br.
authors.forename: Max Cardoso
authors.initials: MC
authors.lastname: Langer
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001938:Brazil; D004032:Diet; D025061:Dinosaurs / Q000033:anatomy & histology* / Q000145:classification / Q000502:physiology*; D005580:Fossils / Q000033:anatomy & histology*; D010802:Phylogeny
keywords: Brazil; Carnian; Dinosauria; Lagerpetidae; Santa Maria Formation; Sauropodomorpha; Triassic; diet