Rodrigo Temp Müller

Universidade Federal de Santa Maria · Department of Biology

The Carnian (Upper Triassic) rocks of the Candelária Sequence present a rich record of dinosaurs, including some of the oldest known dinosaurs worldwide. In this contribution we describe the first unequivocal dinosaur from the Pivetta site, located in the Restinga Sêca municipality, Southern Brazil. The specimen CAPPA/UFSM 0373 is an isolated but w...

The early radiation of dinosaurs was an evolutionary event characterized by distinct episodes. While the earliest unequivocal records are from Carnian strata and relatively well-documented, the subsequent moment of dinosaur radiation is poorly studied. The fossil record of early Norian dinosaurs from Brazil provides one of the best samples regardin...

Agudotherium gassenae is a poorly known non‐mammaliaform probainognathian cynodont from the Late Triassic of southern Brazil. It is known only by mandibular remains, and its affinities within Probainognathia are unclear. Furthermore, its phylogenetic affinities were never investigated through computational analyses. In this study, we described new...

Buriolestes schultzi is a small sauropodomorph dinosaur from Carnian beds (ca., 233 Ma) of southern Brazil. It is one of the earliest members of that lineage and is a key taxon to investigate the initial evolution of Sauropodomorpha. Here, we attribute a new specimen to B. schultzi from Late Triassic of southern Brazil, which represents the first o...

Dinosaurs and pterosaurs have remarkable diversity and disparity through most of the Mesozoic Era1–3. Soon after their origins, these reptiles diversified into a number of long-lived lineages, evolved unprecedented ecologies (for example, flying, large herbivorous forms) and spread across Pangaea4,5. Recent discoveries of dinosaur and pterosaur pre...

The lineage of sauropodomorph dinosaurs raised some of the most impressive animals that ever walked on Earth. However, the massive titans of the Mesozoic Era originated from far smaller dinosaurs. The Triassic beds from Brazil yielded the earliest part of this evolutionary history. Despite the diverse fossil record of early sauropodomorphs, juvenil...

Comprising the oldest unequivocal dinosauromorphs in the fossil record, silesaurs play an important role in the Triassic radiation of dinosaurs. These reptiles provide the main source of information regarding the ancestral body plan of dinosaurs, as well as the basis for biogeographic models. Nevertheless, the co-occurrence of silesaurs and the old...

One of the most remarkable features in sauropod dinosaurs relates to their pneu-matized skeletons permeated by a bird-like air sac system. Many studies described the late evolution and diversification of this trait in mid to late Meso-zoic forms but few focused on the origin of the invasive respiratory diverticula in sauropodomorphs. Fortunately, i...

Tupuxuara deliradamus' was originally described as a tapejarid pterosaur from the Lower Cretaceous Romualdo Formation (Albian) of the Araripe Basin, Northeastern Brazil, and was regarded later by other authors as an indeterminate azhdarchoid. Whereas its taxonomic status remains controversial, its phyloge-netic affinities were never investigated un...

Triassic cynodonts from South America are key taxa in the investigation of the emergence of mammalian characters. One of the most iconic species from the Carnian is Prozostrodon brasiliensis, found in Late Triassic strata from southern Brazil. This non-mammaliaform cynodont represents the earliest-diverging member of Prozostrodontia, a clade that e...

The origin of the air sac system present in birds has been an enigma for decades. Skeletal pneumaticity related to an air sac system is present in both derived non-avian dinosaurs and pterosaurs. But the question remained open whether this was a shared trait present in the common avemetatarsalian ancestor. We analyzed three taxa from the Late Trias...

Characterized by an elongated snout, proterochampsids are carnivorous non-archosaur archosauriforms. The clade is endemic to South America and its fossil record extends from the early Carnian to the late Carnian/early Norian. Nesting close to Archosauria, it is a key clade for understanding the origin and evolution of archosaurian traits. Unfortuna...

Discoveries from South America have increased our knowledge on the early evolutionary history of sauropodomorph dinosaurs. The dietary shift from faunivorous to herbivorous creatures and the increasing body size are both widely documented in the fossil record. Conversely, the initial evolution of the elongated neck is poorly known. It is one of the...

Dinosaur footprints often occur in Late TriassicEarly Jurassic continental sedimentary rocks. While many such tracks can readily be associated with the kinds of dinosaurs that made them, the makers of some footprints have been controversial. Large tridactyl (three-toed) footprints of the ichnogenus Eubrontes are thought by most paleontologists to h...

The origin and evolutionary relationships of ornithischian dinosaurs are topics that have undergone a series of substantial revisions. At present there are several competing hypotheses concerning the relationship between Ornithischia and the other principal clades of Dinosauria. Some hypotheses have posited a tree topology within Dinosauria that im...

The Triassic deposits of South America are key to understand the early radiation of Dinosauromorpha. Though the fossil record of the group is relatively abundant in Carnian- and Norian-aged strata from Argentina and Brazil, Middle Triassic dinosauromorphs are scarce, at least in the Brazilian record. In this contribution, we describe a set of fossi...

Faxinalipterus minimus was originally described as a purported pterosaur from the Late Triassic (early Norian) Caturrita Formation of southern Brazil. Its holotype comprises fragmentary postcranial elements, whereas a partial maxilla was referred to the species. The assignment of Faxinalipterus minimus to Pterosauria has been questioned by some stu...

Carnian (Late Triassic) deposits of South America provide the oldest unequivocal dinosaur records worldwide, most of which has been assigned to the sauropodomorph lineage. This includes Eoraptor lunensis, Panphagia protos, and Chromogisaurus novasi, from the Ischigualasto Formation, Argentina, and Saturnalia tupiniquim, Pampadromaeus barberenai, Bu...

Whereas the oldest dinosaur skeletons have been excavated from mid to late Carnian beds of South America, its close relatives occur in Anisian to early Carnian deposits from Argentina, Tanzania and Zambia. These close relative forms are key taxa regarding the investigation of macroevolution of dinosauromorphs. Early dinosaurs are well-documented fr...

Whereas sauropod dinosaurs from the Jurassic and Cretaceous Periods were the largest land animals that ever lived, some of their early relatives evolved relatively large bodies during the Triassic Period. The evolutionary pathways followed by the earliest sauropodomorphs towards the acquisition of massive bodies are poorly understood. However, new...

Exquisite discoveries and new interpretations regarding an enigmatic group of cursorial avemetatarsalians led to a new phylogenetic hypothesis regarding pterosaur affinities. Previously thought to be dinosaur precursors, lagerpetids are now considered to be the closest relatives to pterosaurs. This new hypothesis sheds light on a new explorable fie...

The anterolateral scar is a raised and generally rounded ossification on the anterolateral face of the femoral head of certain archosaurs, located anterior to the ‘greater trochanter’ and posterior to the femoral head. The presence and shape of this structure in early dinosaurs is still poorly understood. In the present study, the shape and variati...

The notarium is a rigid bony structure, which resulted from the fusion of thoracic vertebrae of some pterosaurs and birds. It is high variable, ranging from two to six fused thoracic vertebrae. In this study, we reviewed and analyzed approximately 270 specimens of neornithine birds (representing 80% of the living orders) and some fossils in order t...

Owenettids are small procolophonoids that survived beyond the Permo-Triassic boundary. The fossil record of owenettids range from the upper Permian to the Middle Triassic. These records come from South Africa, Madagascar, Tanzania, Germany, and Brazil. Despite its conservative anatomy, some species depict some peculiar traits, such as Candelaria ba...

Irajatherium hernandezi is a poorly known non‐mammaliaform cynodont from the Late Triassic of southern Brazil. A new specimen of this cynodont was found in recent fieldwork to the type‐locality, the Linha São Luiz site (Candelária Sequence), providing new insights into the anatomy of this mammalian forerunner. The new specimen comprises a partial s...

The study of sensorial systems of extinct animals provides clues on their biology and behaviour. Olfaction is an important sensory modality, which is used in a range of tasks, such as foraging, reproduction, predator avoidance and social interaction. The olfactory acuity of dinosaurs has been investigated through quantitative approaches. However, t...

Triassic beds from Argentina and Brazil provide the most relevant fossil record of early dinosauriforms in terms of numerical abundance and taxonomic diversity. This record currently represents the best source to understand the origin and early evolutionary radiation of dinosaurs. In the present paper we offer an updated review focused on the avail...

Traversodontidae is a group of Triassic herbivorous/omnivorous cynodonts that represents the most diversified lineage within Cynognathia. In southern Brazil, a rich fossil record of late Middle/mid-Late Triassic cynodonts has been documented, with Exaeretodon riograndensis Abdala, Barberena, and Dornelles, 2002 and Siriusgnathus niemeyerorum Pavana...

Upper Triassic (Carnian) strata from the Candelária Sequence of southern Brazil bear the oldest records of dinosaurs worldwide. In consequence, investigation of the specimens yielded by these fossiliferous units is crucial for a more comprehensive knowledge regarding the origin, early diversification and radiation of dinosaurs. Herein we reassess a...

Dicynodonts represent a speciose clade of non-mammalian synapsids that lived from the middle Permian to the Late Triassic, exhibiting a Pangaean distribution. The South American Norian fossil record is represented by two species: Jachaleria colorata from Argentina and J. candelariensis from Brazil. The Brazilian specimens come from a relatively sma...

The early evolution of theropod dinosaurs is poorly understood. Whereas sauropodomorphs are well-known from the oldest dinosaur bearing outcrops, the record of theropods is fragmentary and ambiguous. The Triassic deposits from Brazil yielded some of the oldest dinosaurs worldwide. These dinosaurs came from two distinct Assemblage Zones (AZ): the Hy...

The present 3D Dataset contains the 3D models of the sacral vertebrae analyzed in "Sacral co-ossification in dinosaurs: The oldest record of fused sacral vertebrae in Dinosauria and the diversity of sacral co-ossification patterns in the group".

The fusion of the sacrum occurs in the major dinosaur lineages, i.e. ornithischians, theropods, and sauropodomorphs, but it is unclear if this trait is a common ancestral condition, or if it evolved independently in each lineage, or even how or if it is related to ontogeny. In addition, the order in which the different structures of the sacrum are...

Our knowledge on the anatomy of the first dinosaurs (Late Triassic, 235–205 Ma) has drastically increased in the last years, mainly due to several new findings of exceptionally well-preserved specimens. Nevertheless, some structures such as the neurocranium and its associated structures (brain, labyrinth, cranial nerves, and vasculature) remain poo...

The Janner site (Upper Triassic of Southern Brazil) has been intensely explored, yielding constant new findings in recent years. Among these some fragmentary dinosaur specimens still not published were sampled. In this contribution, we describe these specimens, which represent five individuals, in order to increase our understanding on the anatomy...

The notarium is the structure formed by fusion of the dorsal vertebrae which occurred independently in pterosaurs and birds. This ankylosis usually involves two to six elements and in many cases, also includes the last cervical vertebra. Fusion can occur in different degrees, uniting the vertebral centra, the neural spines, the transverse processes...

The morphology of the ankle is a crucial topic towards our understanding of the evolutionary history of Archosauria. The morphology of these bones is directly correlated with posture, and subsequently this provides an important phylogenetic signal. The astragalar anatomy is widely adopted in phylogenetic studies of dinosaurs, however, this bone is...

Whereas ornithischian dinosaurs are well known from Jurassic and Cretaceous deposits, deciphering the origin and early evolution of the group remains one of the hardest challenges for palaeontologists. So far, there are no unequivocal records of ornithischians from Triassic beds. Here, we present an alternative evolutionary hypothesis that suggests...

A new fossiliferous site from the Pinheiros-Chiniquá Sequence (Santa Maria Supersequence) with typical tetrapod components of the Dinodontosaurus Assemblage Zone (AZ) is here described. The new site is included in the Faxinal do Soturno Structural Block. The fossil content is characterized by cranial and postcranial material of rauisuchian archosau...

Embora o grupo dos dinossauros sauropodomorfos seja amplamente conhecido em virtude dos gigantescos saurópodes, sua origem ainda é pouco compreendida em virtude da escassez de esqueletos completos ou datações precisas. Entretanto, novos achados e datações realizadas em rochas Triássicas do Brasil têm trazido à tona informações valiosas no que tange...

Ornithosuchidae is one of the most enigmatic clades of Triassic pseudosuchians. The group is composed by three carnivorous species that were excavated from Upper Triassic beds of Scotland and Argentina. We describe the first ornithosuchid from the Upper Triassic sediments of Brazil and explore its phylogenetic affinities and implications for the ev...

Traversodontidae is a less inclusive clade of cynognathian cynodonts that lived during the Triassic. Recently, a traversodontid from the southern Brazilian Triassic beds was described – Siriusgnathus niemeyerorum – based upon specimens found exclusively in its type-locality. No absolute age or index fossils have been reported for this locality, whi...

Several new sauropodomorphs have been described in recent years, including the unaysaurid sauropodomorph Macrocollum itaquii (Late Triassic, Brazil). This study presents a detailed description of the craniomandibular anatomy of M. itaquii based on the holotype, a paratype and a newly referred specimen. A phylogenetic analysis using an updated datas...

The present 3D Dataset contains the 3D models of the skull, brain and inner ear endocast analyzed in "Gnathovorax cabreirai: a new early dinosaur and the origin and initial radiation of predatory dinosaurs". Model IDs Description M3#442 3D model of the skull M3#443 3D model of the braincase M3#444 Endocast of brain, inner ear, and cranial nerves Ta...

Predatory dinosaurs were an important ecological component of terrestrial Mesozoic ecosystems. Though theropod dinosaurs carried this role during the Jurassic and Cretaceous Periods (and probably the post-Carnian portion of the Triassic), it is difficult to depict the Carnian scenario, due to the scarcity of fossils. Until now, knowledge on the ear...

Saturnalia tupiniquim is a sauropodomorph dinosaur from the Late Triassic (Carnian-c. 233 Ma) Santa Maria Formation of Brazil. Due to its phylogenetic position and age, it is important for studies focusing on the early evolution of both dinosaurs and sauropodomorphs. The osteology of Saturnalia has been described in a series of papers, but its cran...

Discoveries in Carnian-aged rocks are establishing a rich and diverse dinosaurian fauna at the so-called 'dawn of the age of dinosaurs' in the Late triassic of Western Gondwana. Accordingly, Brazilian strata from the Candelária Sequence have contributed extensively to this trend. here, we present a new dinosaurian specimen (CAPPA/UFSM 0200) from th...

The controversial dinosauriform Teyuwasu barberenai Kischlat, 1999 (Fig. 1B) is based on a right femur (BSPG AS XXV 53) and tibia (BSPG AS XXV 54), formerly referred to the pseudosuchian ‘Hoplitosuchus raui’ (= Hoplitosaurus raui) Huene, 1938 (see also Huene, 1942). This material comes from a classic Late Triassic (Carnian) locality in southern Bra...

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 the origin of the group. Here we offer three hypotheses based in novel data that can explain this diversity at the first branches of the long evolutionary...

Late Triassic deposits from south Pangea (Argentina and Brazil) bear the oldest (so far) and most informative unequivocal records of dinosaurs worldwide. Herein we describe a new lagerpetid dinosauromorph from a classic dinosaur-bearing locality (Cerro da Alemoa site) from the Candelária Sequence (Santa Maria Formation), southern Brazil, and report...

In the present contribution, we aim to present the osteology of ‘ULBRA-PVT-281’, which comprises the best-preserved skeleton of Prestosuchus chiniquensis ever found. ULBRA-PVT-281 combines the morphology of two classic specimens referred to P. chiniquensis, UFRGS-PV-0156-T and UFRGSPV- 0152-T, reunited in a single operational taxonomic unit (OTU) i...

The rise of sauropodomorphs is still poorly understood due to the scarcity of well-preserved fossils in early Norian rocks. Here, we present an association of complete and exceptionally well-preserved dinosaur skeletons that helps fill that gap. They represent a new species, which is recovered as a member of a clade solely composed of Gondwanan Tri...

The discovery and study of bonebeds can provide unique information on the biology of extinct animals. Here we interpret the taphonomic history of a monotypic bonebed composed by several individuals attributable to the dicynodont Dinodontosaurus sp. collected in a classic locality from the Dinodontosaurus Assemblage Zone (Middle Triassic of Brazil)....

A new Upper Triassic fossiliferous outcrop, the Niemeyer Site, from the Santa Maria Supersequence (Paraná Basin, Southern Brazil) is reported. The lithology found in this locality is consistent with that found in the Candelária Sequence. The high prevalence of traversodontid cynodonts in this site is particularly notable, with collected specimens m...

Ecteniniidae comprises an endemic radiation of carnivore probainognathian cynodonts from the Late Triassic of South America. Three taxa have been included in this clade: Ecteninion lunensis Martínez et al., 1996 and Diegocanis elegans Martínez et al., 2013 from Argentina, and Trucidocynodon riograndensis Oliveira et al., 2010 from Brazil. Herein, a...

As localidades fossilíferas da região central do Rio Grande do Sul provêm os registros inequívocos dos dinossauros mais antigos do mundo. O afloramento Cerro da Alemoa (29°41'51.86"S; 53°46'26.56"O), localizado na zona urbana da cidade de Santa Maria (Rio Grande do Sul) e pertencente à Zona de Associação de Hyperodapedon da Sequência Candelária (i....

An exceptional new specimen (CAPPA/UFSM 0035) of Buriolestes schultzi was discovered during recent fieldwork at the type locality of the taxon, which is Carnian in age (Late Triassic). This early sauropodomorph is peculiar owing to its faunivorous feeding habits, unusual amongst the members of this large omnivorous/herbivorous clade. The specimen i...

Saturnaliinae is a group of Carnian sauropodomorphs, mainly represented by Chromogisaurus Ezcurra, 2010 and Saturnalia Langer, 1999. Pelvic girdle elements are frequently preserved in its representatives, which are characterized by conspicuous rugosities in the iliac dorsal portion, representing muscle scars (iliac blade rugosity, IBR; post-acetabu...

Among dinosauromorphs, one of the most enigmatic clades is the Lagerpetidae. Only recently these small and cursorial forms are receiving the appropriate attention, since new specimens are shedding light on their anatomy and helping to establish evolutionary hypotheses to them. Most lagerpetids are known only by their hindlimb, specially the femur,...

A recently published study [1] reassessed the phylogenetic relationships of Chilesaurus diegosuarezi, proposing its affinities to ornithischians rather than theropods as previously suggested [2]. However, we observed that the results presented by Baron & Barrett [1] could not be replicated using the same dataset and parameters provided by the autho...

Despite representing a key-taxon in dinosauromorph phylogeny, Lagerpertidae is one of the most obscure and enigmatic branches from the stem that leads to the dinosaurs. Recent new findings have greatly increased our knowledge about lagerpetids, but no phylogenetic analysis has so far included all known members of this group. Here, we present the mo...

Recently, a new completely unorthodox phylogenetic hypothesis regarding both early dinosaurian taxa and major less inclusive groups has been suggested. Immediately after, several new datasets have been produced, resulting in interesting ways to test affinities of distinct taxa. Accordingly, we here aim to access the affinities of the enigmatic Chil...

Dinossauros do Sul do Brasil e da Argentina estão entre os mais antigos registrados ao redor do mundo, sendo, portanto, de fundamental importância para o estudo da origem e diversificação desta linhagem. O ílio é um osso bem representado nos dinossauros mais basais e contém informações suficientes para sua identificação mesmo, quando encontrado iso...