Contribuição ao conhecimento dos lepidosauromorpha (Reptilia Diapsida) do triássico superior do Rio Grande do Sul, Brasil : aspectos anatômicos, filogenéticos e paleobiológicos

Lepidosauromporpha e Archosauromorpha são os dois grandes grupos dentro de Diapsida. O primeiro é composto por Lepidosauria e os seus stem taxa, todos extintos. Na atualidade o grupo está unicamente representado por Lepidosauria (Squamata e Rhynchocephalia) e encontra-se amplamente distribuído pelo mundo, ocupando diversos hábitats. Das 10.418 espécies viventes conhecidas, apenas Sphenodon punctatus pertence a Rhynchocephalia. Apesar de no passado o grupo também ter sido diverso, sua origem evolução inicial encontram-se ainda pouco conhecidas. Indiretamente, estima-se que o surgimento do grupo deve ter ocorrido no Permiano, embora o primeiro fóssil atribuído a um Lepidosauromorpha tenha idade triássica. No contexto sulamericano, na Argentina e no Brasil estão os registros mais antigos (Noriano), representados pelos rincocefálios, Sphenotitan leyesi, da Argentina, e Clevosaurus brasiliensis, do Brasil, e pelo lepidossauromorfo Cargninia enigmatica. Os dois últimos são provenientes da Zona de Associação (ZA) de Riograndia da Sequencia Candelária (Supersequência Santa Maria do Rio Grande do Sul). Novos materiais inéditos têm sido coletados na ZA de Riograndia, e, também, na mais antiga ZA de Hyperodapedon, de idade Carniana. A presente tese traz novas contribuições ao conhecimento dos Lepidosauromorpha sulamericanos, na forma de quatro artigos científicos. Assim, a tese fornece o seguinte aporte de contribuições: o registro da evidência mais antiga de osteomielite em rincocefálios, observadas em mandíbulas de Clevosaurus brasiliensis; a descrição de uma nova espécie de rincocefálio para ZA de Riograndia; a revisão anatômica e o posicionamento filogenético de Cargninia enigmatica; a descrição de novos materiais de lepidossauromorfos da ZA de Riograndia; e a descrição de um novo rincocefálio baseado em um fragmento de palatino para a ZA de Hyperodapedon, junto com a descrição detalhada do palatino de Clevosaurus brasiliensis. Através de abordagens anatômica, taxonômica, filogenética, paleoecológica e paleobiológica, os artigos integrantes da tese, em conjunto, fornecem novas informações sobre a história inicial dos (Lepidosauromorpha (Lepidosauria)) e sua radiação no início do Mesozoico.Lepidosauromporpha and Archosauromorpha are the largest groups inside the Diapsida clade. Lepidosauromorpha comprises Lepidosauria and its stem taxa, all extinct. Currently, the group is only represented by Lepidosauria (Squamata and Rhynchocephalia), being widely distributed across the world, occupying several habitats. There are 10.418 known extant species, but only Sphenodon punctatus belongs to Rhynchocephalia. Despite the past diversity of the group, its origin and early evolution are still little known. Indirectly, it is estimated that the rise of the group should have occurred during the Permian, although the first fossil attributed to Lepidosauromorpha is of Triassic age. In the South American context, the oldest records (Norian) are found in Argentina and Brazil, comprising the rhinchocephalians Sphenotitan leyesi, from Argentina, and Clevosaurus brasiliensis, from Brazil, as well as the lepidosauromorph Cargninia enigmatica. The Brazilian taxa come from the Riograndia Assemblage Zone (AZ) of the Candelária Sequence (Santa Maria Supersequence of Rio Grande do Sul State). New undescribed specimens have been collected from the Riograndia AZ, but also from the older Hyperodapedon AZ, of Carnian age. The present thesis brings new contributions to the South American Lepidosauromorpha knowledge and is organized into four scientific papers. Thus, the thesis furnishes the following contribution: the record of the oldest evidence of osteomyelitis in Rhynchocephalians observed in jaws of Clevosaurus brasiliensis; the description of a new species of rhynchocephalian from the Riograndia AZ; the anatomical revision and phylogenetic position of Cargninia enigmatica; the description of new lepidosauromorphs material from the Riograndia AZ; a new rhynchocephalian based on a palatine fragment from the Hyperodapedon AZ, along with the detailed description of the palatine of Clevosaurus brasiliensis. Through anatomical, taxonomic, phylogenetic, paleoecological and paleobiological approaches, the set of articles that compose the thesis provides new information about the initial history of (Lepidosauromorpha (Lepidosauria)) and its radiation at the beginning of the Mesozoic

The diversity of Triassic South American sphenodontians: a new basal form, clevosaurs, and a revision of rhynchocephalian phylogeny

Rhynchocephalians are a group of lizard-like diapsid reptiles that were very diverse during the Mesozoic but are now restricted to a single extant genus in New Zealand. Recent cladistic analyses have revealed two major clades, Eusphenodontia and the more crownward Neosphenodontia, but relationships of individual taxa have remained difficult to determine because of missing data and an unrevised data matrix. Here we drastically revise the established data matrix on rhynchocephalians by reassessing, evaluating, and adding new characters and operational taxonomic units, differing from any previous analyses in our goal to consider all known rhynchocephalians. In addition, we describe a new genus and species of an early eusphenodontian taxon from the Norian of southern Brazil, with a unique mosaic of plesiomorphic and apomorphic traits, and we re-examine the craniodental anatomy of the eusphenodontian Clevosaurus brasiliensis with µCT imaging, revealing a unique form of acrodonty amongst rhynchocephalians.Fil: Chambi Trowell, Sofia A. V.. University of Bristol; Reino UnidoFil: Martinelli, Agustín Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Whiteside, David I.. University of Bristol; Reino UnidoFil: Romo de Vivar Martínez, Paulo Rodrigo. Universidade Federal do Rio Grande do Sul; BrasilFil: Bento Soares, Marina. Universidade Federal do Rio Grande do Sul; BrasilFil: Schultz, Cesar. Universidade Federal do Rio Grande do Sul; BrasilFil: Gill, Pamela G.. University of Bristol; Reino UnidoFil: Benton, Michael J.. University of Bristol; Reino UnidoFil: Rayfield, Emily J.. University of Bristol; Reino Unid

A New Clevosaurid from the Triassic (Carnian) of Brazil and the Rise of Sphenodontians in Gondwana

The early evolution of lepidosaurs is marked by an extremely scarce fossil record during the Triassic. Importantly, most Triassic lepidosaur specimens are represented by disarticulated individuals from high energy accretion deposits in Laurasia, thus greatly hampering our understanding of the initial stages of lepidosaur evolution. Here, we describe the fragmentary remains of an associated skull and mandible of Clevosaurus hadroprodon sp. nov., a new taxon of sphenodontian lepidosaur from the Late Triassic (Carnian; 237–228 Mya) of Brazil. Referral to Sphenodontia is supported by the combined presence of a marginal dentition ankylosed to the apex of the dentary, maxilla, and premaxilla; the presence of ‘secondary bone’ at the bases of the marginal dentition; and a ventrally directed mental process at the symphysis of the dentary. Our phylogenetic analyses recover Clevosaurus hadroprodon as a clevosaurid, either in a polytomy with the Late Triassic to Early Jurassic Clevosaurus and Brachyrhinodon (under Bayesian inference), or nested among different species of Clevosaurus (under maximum parsimony). Clevosaurus hadroprodon represents the oldest known sphenodontian from Gondwana, and its clevosaurid relationships indicates that these sphenodontians achieved a widespread biogeographic distribution much earlier than previously thought.Fil: Hsiou, Annie S.. Universidade de Sao Paulo; BrasilFil: Nydam, Randall L.. Midwestern University; Estados UnidosFil: Simões, Tiago R.. University of Alberta; Canadá. Harvard University; Estados UnidosFil: Pretto, Flávio A.. Universidade Federal de Santa Maria; BrasilFil: Onary, Silvio. Universidade de Sao Paulo; BrasilFil: Martinelli, Agustín Guillermo. Universidade Federal do Rio Grande do Sul; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Liparini, Alexandre. Universidade Federal de Sergipe; BrasilFil: Romo de Vivar Martínez, Paulo Rodrigo. Universidade Federal do Rio Grande do Sul; BrasilFil: Soares, Marina. Universidade Federal do Rio Grande do Sul; BrasilFil: Schultz, Cesar. Universidade Federal do Rio Grande do Sul; BrasilFil: Caldwell, Michael Wayne. University of Alberta; Canad

Unus pro omnibus, omnes pro uno: on honomyms and synonyms in the taxonomic history of the Tuátara (Sphenodon punctatus)

El Tuátara o Sphenodon punctatus es un lepidosaurio endémico de Nueva Zelanda y único representante actual del grupo de los rincocefalios. Este reptil ha llamado la atención del ser humano desde los primeros contactos, empezando por los Maorís, ya que el Tuátara es un animal importante en la cosmovisión de este pueblo, y posteriormente, para los primeros europeos que llegaron a Nueva Zelanda durante las expediciones inglesas al Pacífico, destacándose el asombro que produjo en los naturalistas. Algunos ejemplares del Tuátara fueron llevados a Inglaterra y depositados en el Museum of the College of Surgeons y en el British Museum, con escasos o nulos datos de colecta, lo cual era común para la época. En este contexto, el Tuátara fue descrito tres veces, recibiendo tres nombres a nivel de género, y curiosamente un mismo ejemplar fue descrito en dos ocasiones. Estos nombres fueron Sphenodon Gray 1831, Hatteria Gray 1842 y Rhynchocephalus Owen 1845. Además, compartió dos de sus nombres con otros organismos. El caso del Tuátara es uno entre muchos donde se dieron los casos de sinonimias y homonimias dentro de la historia de la taxonomía zoológica.The Tuatara or Sphenodon punctatus is an endemic lepidosaur of New Zealand and the only extant representative of the rhynchocephalian clade. This reptile has attracted the attention of the human being since the first contacts; initially, with the Maoris, being an important creature present in their worldview, and later, for the first Europeans who arrived in New Zealand, during the English expeditions to the Pacific, standing out to the naturalists. Some specimens of the Tuatara were taken to England, and deposited in two institutions: at the Museum of the College of Surgeons, and at the British Museum, with little or no data of collection as was common at the time. In this context, the Tuatara was described three times receiving three names at the genus level, and curiously the same example was described twice. These names were Sphenodon Gray 1831, Hatteria Gray 1842, and Rhynchocephalus Owen 1845. In addition, it shared two of its names with other animals. Thus, the case of the Tuatara is one among many where there were cases of synonymy and homonymy within the history of zoological taxonomy.Fil: Romo de Vivar Martínez, Paulo Rodrigo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Martinelli, Agustín Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

To be or not to be: The hidden side of Cargninia Enigmatica and other puzzling remains of Lepidosauromorpha from the Upper Triassic of Brazil

In this contribution, we re-describe the holotype (i.e., the posterior fragment of a left dentary with dentition) of Cargninia enigmatica from the Riograndia Assemblage Zone, Candelária Sequence, Santa Maria Supersequence (Upper Triassic, Brazil), originally considered a member of the Lepidosauria. In addition, two other specimens of lepidosauromorphs from the same locality are described and compared. Broad comparisons suggest that C. enigmatica possesses a unique combination of features, but several key features are widely distributed among basal non-rhynchocephalian lepidosauromorphs and kuehneosaurids. Thus, two possible scenarios are proposed: (1) Cargninia is a basal non-lepidosaurian lepidosauromorph, or (2) it is a basal lepidosaurian. The new specimens are a portion of a right maxilla with teeth (in two fragments) and a fragment of a dentary with teeth. The first specimen is identified as a lepidosauromorph because the maxilla cannot be directly compared with the holotype of C. enigmatica and it is difficult to evaluate if the differences in the dentition (upper versus lower teeth) are the result of intra- or interspecific variation. The dentary, on the other hand, is tentatively referred to C. enigmatica. These specimens together add new clues to understanding the early evolution of Lepidosauromorpha.Fil: Romo de Vivar Martínez, Paulo Rodrigo. Universidade Federal do Rio Grande do Sul; BrasilFil: Martinelli, Agustín Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Fonseca, Pedro Henrique M.. Universidade Federal do Rio Grande do Sul; BrasilFil: Soares, Marina Bento. Universidade Federal do Rio Grande do Sul; Brasi

New rhynchocephalian specimen in the Late Triassic of southern Brazil and comments on the palatine bone of Brazilian rhynchocephalians

Triassic rhynchocephalians from South America are relatively sparse, based on one taxon from the Norian of Argentina (i.e., Sphenotitan leyesi) and three records from the Late Carnian (i.e., indet. taxon) and Norian (i.e., Clevosaurus brasiliensis and indet. taxon) of Brazil. We described here a new occurrence of rhynchocephalians from a new Late Carnian locality of southern Brazil, based on an isolated palatine with teeth, referred to that group due to the morphological similarity whit the palatines of the other taxa of the same group. The specimen comes from the municipality of Vale do Sol, collected within a layer with abundant material of Hyperodapedon sp. (Rhynchosauria), which is referred to the Hyperodapedon Assemblage Zone (Late Carnian) of the Candelária Sequence, Santa Maria Supersequence. The isolated palatine here described cannot be referred to any hitherto known species, but it provides an additional record for the few putative ones of Carnian age in South America. Moreover, we figure and describe the palatine anatomy of Clevosaurus brasiliensis, based on two specimens, which have relevant data poorly addressed in previous contributions.Fil: Romo de Vivar Martínez, Paulo Rodrigo. Universidade Federal do Rio Grande do Sul; BrasilFil: Martinelli, Agustín Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Paes Neto, Voltaire D.. Universidade Federal do Rio Grande do Sul; BrasilFil: Scartezini, Camila A.. Universidade Federal do Rio Grande do Sul; BrasilFil: Lacerda, Marcel B.. Universidade Federal do Paraná; BrasilFil: Rodrigues, Carlos N.. Museu Municipal Aristides Carlos Rodrigues; BrasilFil: Soares, Marina Bento. Universidade Federal do Rio Grande do Sul; Brasi