Maniraptoran theropod ungual from the Marília Formation (Upper Cretaceous), Brazil

Novas, Fernando E.; Ribeiro, Luis Carlos Borges; Carvalho, Ismar de Souza

doi:10.22179/revmacn.7.344

Cited by 78 publications

(29 citation statements)

References 10 publications

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“…Some smaller unguals possess a proximodorsal lip and a prominent ventral flexor tubercle, which are here recognized as corresponding to the third manual digit. Proximal dorsal lips are absent in manual unguals of compsognathids and Ornitholestes, but they are present in some derived coelurosaurs such as oviraptorosaurs and paravians (Novas et al, 2005), as well as in some basal taxa, including Tanycolagreus and Guanlong (Carpenter et al, 2005;Xu et al, 2006). However, due to the restricted distribution of this feature among coelurosaurs, we assume that the presence of dorsal lips in some of the manual unguals of Bicentenaria may constitute an autapomorphic trait of this taxon.…”

Section: Systematicsmentioning

confidence: 99%

New Patagonian Cretaceous theropod sheds light about the early radiation of Coelurosauria

Novas¹,

Ezcurra²,

Agnolín³

et al. 2012

MACN

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Abstract:Here we describe a new theropod, Bicentenaria argentina nov. gen. et nov. sp., from the early Late Cretaceous of Patagonia. It is represented by more than a hundred bones belonging to different sized individuals, which were buried together in disarticulation after little transportation. The available association of skeletal elements suggests a gregarious behaviour for Bicentenaria, an ethological trait also recorded among other theropod clades. Increasing documentation of monospecific assemblages of different groups of theropods suggests that a gregarious behaviour may have constituted the ancestral condition for Theropoda, at least. Bicentenaria characterizes for the surangular bone with a high dorsal margin and a prominent lateral shelf, a retroarticular process that is low, wide and spoon-shaped, and quadrate bone with its lateral condyle larger than the medial one. Phylogenetic analysis found the Chinese Tugulusaurus and the Patagonian Bicentenaria as successive sister taxa of all other coelurosaurs, thus revealing the importance of the new taxon in the understanding of the early diversification of Coelurosauria. In particular, Bicentenaria amplifies the array of basal coelurosaurs that inhabited Gondwana during the Cretaceous, also including compsognathids, Aniksosaurus and Santanaraptor. Although still restricted to a handful of forms, available information indicates that Gondwana was a cradle for the evolution of different lineages of basal coelurosaurs, different from those documented in Upper Cretaceous beds in the northern landmasses. Analysis of body size distribution in averostran theropods results in the identification of two main episodes of drastic size reduction in the evolutionary history of Coelurosauria: one occurred at the initial radiation of the group (as represented by Bicentenaria, Zuolong, Tugulusaurus, compsognathids, and Aniksosaurus), and a second episode occurred at the early diverification of Paraves or avialans. Reduction in body size may have allowed adult coelurosaurians to exploit ecological niches not occupied before by larger basal averostrans.Key words: Coelurosauria, gregarism, body size reduction, Cretaceous, South America.Resumen: Nuevo terópodo del Cretácico de Patagonia brinda nuevas evidencias acerca de la radiación temprana de Coelurosauria. En la presente contribución se describe el nuevo terópodo Bicentenaria argentina nov. gen. et nov. sp., del Cretácico Tardío temprano de Patagonia. El nuevo taxón se encuentra representado por más de una centena de huesos pertenecientes a individuos de diferentes tamaños, los cuales fueron enterrados todos juntos en desarticulación, luego de un leve transporte. La asociación disponible de materiales sugiere hábitos gregarios para Bicentenaria, un rasgo etológico también registrado en otros clados de terópodos. La documentación recurrente de asociaciones monoespecíficas de diferentes grupos de terópodos sugiere que los hábitos gregarios pudieron haber constituido la condición ancestral para Theropoda. Bicentenaria se caract...

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Section: Systematicsmentioning

confidence: 99%

New Patagonian Cretaceous theropod sheds light about the early radiation of Coelurosauria

Novas¹,

Ezcurra²,

Agnolín³

et al. 2012

MACN

Self Cite

View full text Add to dashboard Cite

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“…Among these, only the first has further skeletal evidence, i.e., the partial skeleton of Pycnonemosaurus nevesi Kellner and Campos, 2002, a maxillary fragment described by Bertini (1996), and the partial remains (vertebra, femur and phalanges) described by Novas et al (2008). Other theropod skeletal records include a scapula ) and an ungual phalanx (Novas et al 2005b) attributed to Maniraptora, and still undescribed Enanthiornithes remains (Alvarenga and Nava 2005). Once proposed spinosaurid occurrences in the Bauru Group were not confirmed (Candeiro et al 2006a).…”

Section: Bauru and Parecis Groupsmentioning

confidence: 99%

Mesozoic dinosaurs from Brazil and their biogeographic implications

Bittencourt

Langer

2011

An. Acad. Bras. Ciênc.

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The record of dinosaur body-fossils in the Brazilian Mesozoic is restricted to the Triassic of Rio Grande do Sul and Cretaceous of various parts of the country. This includes 21 named species, two of which were regarded as nomina dubia, and 19 consensually assigned to Dinosauria. Additional eight supraspecific taxa have been identified based on fragmentary specimens and numerous dinosaur footprints known in Brazil. In fact, most Brazilian specimens related to dinosaurs are composed of isolated teeth and vertebrae. Despite the increase of fieldwork during the last decade, there are still no dinosaur body-fossils of Jurassic age and the evidence of ornithischians in Brazil is very limited. Dinosaur faunas from this country are generally correlated with those from other parts of Gondwana throughout the Mesozoic. During the Late Triassic, there is a close correspondence to Argentina and other south-Pangaea areas. Mid-Cretaceous faunas of northeastern Brazil resemble those of coeval deposits of North Africa and Argentina. Southern hemisphere spinosaurids are restricted to Africa and Brazil, whereas abelisaurids are still unknown in the Early Cretaceous of the latter. Late Cretaceous dinosaur assemblages of south-central Brazil are endemic only to genus or, more conspicuously, to species level, sharing closely related taxa with Argentina, Madagascar, Indo-Pakistan and, to a lesser degree, continental Africa.

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“…They are from the Peirópolis Site, in Minas Gerais State, a place that has yielded a great number of bones of titanosaurid sauropods (Baurutitan britoi and Uberabatitan riberoi) and crocodylomorphs (Itasuchus jesuoinoi, Peirosaurus tormini and Uberabasuchus terrificus). In contrast, to the theropoda record is only represented by teeth (this work), an Abelisauridae vertebra (Novas et al, 2008), a tetanuran scapula (Machado et al, 2008), and a maniraptoran claw (Novas et al, 2005). The present Abelisauridae and Carcharodontosauridae reports from Peirópolis indicates that this group has a larger geographical distribution in the Gondwana landmasses, which is the most extensive theropod tooth assemblage from Brazil.…”

Section: Discussionmentioning

confidence: 61%

Dentes de terópodes da Formação Marília (Neomaastrichtiano) do sítio paleontológico de Peirópolis do estado de Minas Gerais, Brasil

2012

Rev. bras. geociênc.

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Theropod teeth can be separated at the family level using the basal cross-section, and by the presence or absence of wrinkles in the enamel of the tooth crowns. Theropods comprise the most common vertebrate remains in the fossil assemblage from the Serra da Galga Member, Marília Formation (late Maastrichtian) in the Bauru Basin Peirópolis paleontological site (Uberaba Town, Minas Gerais State), in southeastern Brazil. In this study, cross-sectional outlines of the teeth and wrinkles on the surfaces of the crowns were used to group the teeth into nine morphological classes. The tooth cross-sections were drawn using a copper wire to contour the outlines of the most proximal portions of the tooth crowns. Other features were analyzed using a microscope. Within the nine morphological classes, morphotypes one and two can be assigned to the Abelisauridae, and morphotypes three to seven belong to the Carcharodontosauridae. This is the most abundant record of Abelisauridae in Minas Gerais State, Brazil. Morphotypes eight and nine were not identified because they do not have any diagnostic features of known Gondwanan or Laurasian taxa. The presence of Carcharodontosauridae teeth in the Member of Serra da Galga (late Maastrichtian) is the youngest record for this family.Keywords: dinosaur; Late Cretaceous; theropod teeth; Minas Gerais State; Brazil. Resumo Dentes de terópodes da Formação Marília (Neomaastrichtiano) do sítio paleontológico de Peirópolis do estado de Minas Gerais, Brasil.Dentes de dinossauros terópodes possuem várias características morfológicas a nível familiar. As principais características diagnósticas são: a forma do dente em seção transversal e a presença de enrugamentos na coroa do dente. Terópodes representam os restos de vertebrados mais comuns na assembleia fóssil do Membro Serra da Galga, Formação Marília (Neomaastrichtiano), Bacia Bauru, no sítio paleontológico de Peirópolis (cidade de Uberaba, estado de Minas Gerais), no Sudeste do Brasil. Neste estudo, seções transversais dos dentes e enrugamentos nas faces das coroas foram utilizadas para agrupar os dentes em nove classes morfológicas. As seções transversais dos dentes foram desenhadas utilizando-se um fio de cobre para contornar as porções mais proximais de suas respectivas coroas. Outras características foram analizadas, usando-se um microscópio. Dentro das dez classes morfológicas, os morfotipos um e dois podem ser atribuídos ao Abelisauridae, enquanto que os morfotipos três a sete pertencem a Carcharodontosauridae. Os dentes de Abelisauridae são os mais abudantes no registro fossilífero no Sítio de Peirópolis, em Minas Gerais, no Brasil. Os morfotipos oito e nove não foram identificados pois não apresentam nenhuma característica diagnóstica de terópodes conhecidos no Gondwana ou na Laurásia. A presença de dentes Carcharodontosauridae, no Membro Serra da Galga (Neomaastrichtiano), é o registro geológico mais recente desta família.Palavras-chave: dinossauros; Neocretáceo; dentes de terópodes; estado de Minas Gerais; Brasil.

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Maniraptoran theropod ungual from the Marília Formation (Upper Cretaceous), Brazil

Cited by 78 publications

References 10 publications

New Patagonian Cretaceous theropod sheds light about the early radiation of Coelurosauria

New Patagonian Cretaceous theropod sheds light about the early radiation of Coelurosauria

Mesozoic dinosaurs from Brazil and their biogeographic implications

Dentes de terópodes da Formação Marília (Neomaastrichtiano) do sítio paleontológico de Peirópolis do estado de Minas Gerais, Brasil

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