Dinosaurs and pterosaurs have remarkable diversity disparity through most of the Mesozoic Era1–3. Soon after their origins, these reptiles diversified into a number long-lived lineages, evolved unprecedented ecologies (for example, flying, large herbivorous forms) spread across Pangaea4,5. Recent discoveries dinosaur pterosaur precursors6–10 demonstrated that animals were also speciose widespread, but those precursors few if any well-preserved skulls, hands associated skeletons11,12. Here we...

Resolving the evolutionary relationships of early diverging ('basal') ornithischian dinosaurs is a challenging topic in palaeontology, with multiple competing hypotheses on phylogenetic heterodontosaurids, 'hypsilophodontids', and other early-diverging forms. These cannot be directly compared because they are derived from differently constructed datasets (i.e. distinct samples taxa characters). This study aims to address these issues by revising combining into single analysis order create...

Whereas ornithischian dinosaurs are well known from Jurassic and Cretaceous deposits, deciphering the origin early evolution of group remains one hardest challenges for palaeontologists. So far, there no unequivocal records ornithischians Triassic beds. Here, we present an alternative evolutionary hypothesis that suggests consideration traditional ‘silesaurids' as a low-diversity clades representing stem leading to core (i.e. unambiguous ornithischians, such Heterodontosaurus tucki ). This...

The controversial dinosauriform Teyuwasu barberenai Kischlat, 1999 (Fig. 1B) is based on a right femur (BSPG AS XXV 53) and tibia 54), formerly referred to the pseudosuchian 'Hoplitosuchus raui' (= Hoplitosaurus raui) Huene, 1938 (see also 1942). This material comes from classic Late Triassic (Carnian) locality in southern Brazil 1A), Cerro da Alemoa outcrop complex, that has yielded several noteworthy tetrapod specimens Garcia et al., 2019, for complete list of references). When reviewing...

Abstract The origin and evolutionary relationships of ornithischian dinosaurs are topics that have undergone a series substantial revisions. At present there several competing hypotheses concerning the relationship between Ornithischia other principal clades Dinosauria. Some posited tree topology within Dinosauria imply ‘ghost-lineage’ for (whose representatives make their first unambiguous appearance in Hettangian) extends through portion Triassic time. In contrast, placed conventionally...

Comprising the oldest unequivocal dinosauromorphs in fossil record, silesaurs play an important role Triassic radiation of dinosaurs. These reptiles provide main source information regarding ancestral body plan dinosaurs, as well basis for biogeographic models. Nevertheless, co-occurrence and dinosaurs is rare, which hampers reliable ecological inferences. Here we present first species silesaur from dinosaur-bearing beds Brazil. Amanasaurus nesbitti gen. et sp. nov. possesses a unique set...

This paper investigates the nonlinear geometric effect on mechanical behavior of shape memory alloy (SMA) helical springs. First, SMA wires are characterized, and then design fabrication springs discussed. Experimental tensile tests carried out to show influence. Results a coupling between constitutive nonlinearities that defines spring stiffness. Two with different geometries built from define both weak strong Numerical analyses developed, using finite element method confirm general...

Abstract Pterosaurs, remarkable for their extensive evolutionary history and role as the first vertebrates to achieve active flight, have long intrigued paleontologists public alike. Spanning over 150 million years vanishing at end of Mesozoic Era, pterosaurs represent a major radiation within terrestrial ecosystems. Despite prominence, origins remained complex puzzle in paleontology 200 years. We present comprehensive catalog pterosaur precursors specimens from Upper Triassic Candelária...

Introdução. A variação intraespecífica refere-se às diferenças morfológicas ou comportamentais observadas entre indivíduos de uma mesma espécie, sendo determinadas por diversos fatores, como mudanças ontogenéticas; dimorfismo sexual; individual e condições patológicas devido a doenças lesões. Objetivo. O presente estudo apresenta, forma breve, os principais fatores que geram nos primeiros dinossauros, bem meios analisá-la (e.g., investigação da morfologia externa, morfometria, histologia)....

Several new early sauropodomorphs have been described from Carnian South American strata that include the oldest unambiguous dinosaurs worldwide. Hence, these findings suggest a high diversity in origin of group. Here we offer three hypotheses based novel data can explain this at first branches long evolutionary tree sauropodomorphs. The hypothesis explains Triassic specimens excavated Brazilian are not coeval owing to lack stratigraphic control. Fortunately, studies constraining age...

Abstract The Carnian (Upper Triassic) rocks of the Candelária Sequence present a rich record dinosaurs, including some oldest known dinosaurs worldwide. In this contribution we describe first unequivocal dinosaur from Pivetta site, located in Restinga Sêca municipality, Southern Brazil. specimen CAPPA/UFSM 0373 is an isolated but well‐preserved left ilium. A thorough examination specimen's anatomy and phylogenetic analysis provides evidence that belongs to Herrerasauria. We were able...

Discoveries in Carnian-aged rocks are establishing a rich and diverse dinosaurian fauna at the so-called 'dawn of age dinosaurs' Late Triassic Western Gondwana. Accordingly, Brazilian strata from Candelária Sequence have contributed extensively to this trend. Here, we present new specimen (CAPPA/UFSM 0200) geological unit. The material was collected fossiliferous site that had no previous record dinosaurs. Our comprises single ilium, which describe detail. Its anatomy is consistent with...

Upper Triassic (Carnian) strata from the Candelária Sequence of southern Brazil bear oldest records dinosaurs worldwide. In consequence, investigation specimens yielded by these fossiliferous units is crucial for a more comprehensive knowledge regarding origin, early diversification and radiation dinosaurs. Herein we reassess dinosaur specimen Brazil, informally known as ‘Big Saturnalia’, supposed large-sized sauropodomorph unearthed at ‘Cerro da Alemoa’ locality in Santa Maria municipality,...

Rodrigo Temp Müllerab* , Mauricio Silva Garciaab & André de Oliveira Fonsecaca Centro Apoio à Pesquisa Paleontológica da Quarta Colônia, Universidade Federal Santa Maria, Rua Maximiliano Vizzotto, 598, 97230-000 São João do Polêsine, RS, Brazilb Programa Pós-Graduação em Biodiversidade Animal, 97105-120 Brazilc Laboratório Geologia e Pedologia Juiz Fora, 36036-900 MG, Brazil

Abstract The lineage of sauropodomorph dinosaurs raised some the most impressive animals that ever walked on Earth. However, massive titans Mesozoic Era originated from far smaller dinosaurs. Triassic beds Brazil yielded earliest part this evolutionary history. Despite diverse fossil record early sauropodomorphs, juvenile specimens, as well certain species are poorly sampled. This is case for Unaysaurus tolentinoi , an unaysaurid Caturrita Formation (ca. 225 Ma; Norian, Late Triassic)....