Jonathas Bittencourt

Federal University of Minas Gerais | UFMG · Departamento de Geologia

During the Mesozoic, non-avian theropods represented one of the most successful clades globally distributed, with a wide diversity of forms. An example is the clade Megalosauroidea, which included medium- to large-bodied forms. Here, we analyse the macroevolution of the locomotor system in early Theropoda, emphasizing the Megalosauroidea. We scored...

This study investigates paleoenvironmental changes at the Paleolagoa Seca site, an Upper Quaternary locality of lacustrine origin in central Brazil. We present charcoal and pollen analyses of this sedimentary sequence, and assess how they compare with previously published fossil macroflora and paleoclimatic reconstructions of the same site and adja...

The Feliz Deserto Formation (Berriasian–Valanginian, Sergipe-Alagoas Basin, NE Brazil) preserved some of the earliest South American fossil records of the rifting stages which resulted in the Gondwana supercontinent break-up during the Lower Cretaceous. Recently, the first spinosaurid theropod record of this formation was described, based on a toot...

A Formação Feliz Deserto preservou alguns dos registros iniciais do rifteamento que fragmentou o Gondwana. Recentemente foi reportada a primeira ocorrência de Spinosauridae de um afloramento (Canafístula 01) às margens da rodovia SE–202 (Japoatã, Sergipe). Reportamos novos materiais desta localidade, incluindo um fragmento de falange de Theropoda e...

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...

A new genus and species of Ephemeroptera, Astraeoptera cretacica gen. et sp. nov., is described from the Lower Cretaceous limestone of the Crato Formation (Brazil). The new taxon has the following diagnostic characters: veins MP2 e CuA straight at their bases, MA branching in the apical half of wing length, CuA not forked, cubital field with longit...

The first segmented wormlike specimen from the Lower Cretaceous (Barremian-Aptian) Quiricó Formation (Sanfranciscana Basin) is described. The new fossil was preserved in a lacustrine environment within an arid tropical climate, associated with abundant fishes and plant remains. The incomplete small specimen (size order of 6 mm) has ca. 40 body segm...

This study is the first report of the fossil macroflora of the Paleolagoa Seca, an Upper Quaternary fossil locality of lacustrine origin in central Brazil. Here we present an analysis of well-preserved fossil leaves collected from an argillite level dated at ca. 43,000 cal yr BP and discuss the paleoclimatic implications of this record. We reconstr...

This article presents a detailed description of stromatolites formed simultaneously with caves’ bedrock, within karstic areas in Southeastern Brazil. We discuss the importance of such fossils for geoconservation and their legal preservation under the Brazilian law. Six caves are described with occurrences of Conophyton-type stromatolites. All those...

Squamates have an extremely long evolutionary history with a fossil record that extends into the Middle Triassic. However, most of our knowledge of their early evolutionary history is derived from Laurasian records. Therefore, fundamental questions regarding the early evolution of squamates in the Southern Hemisphere, such as the origins of the ext...

We report new data on the geology and the fossil record of the Sanfranciscana Basin in sites to the north of the traditionally explored localities within Minas Gerais. The strata in the new explored area are formed by distinct lithologies, encompassing pelitic rocks with caliche levels and metric bodies of cross-bedded sandstone towards the top, si...

The first chondrichthyan teeth, dermal and oropharyngeal denticles from the Lower Cretaceous lacustrine Quiricó Formation (Sanfranciscana Basin), in southeastern Brazil are described. Eight microremains morphologies have been recovered from lower levels of this formation, dated as possibly Valanginian with basis on ostracods. The dermal denticles b...

The main objective of this work is to present a survey of the fossil record of “conchostracans”, a group of continental (also occasionally from brackish and marine sequences) fossil invertebrates, recorded from Africa, to explore relationships among these taxa and those recorded from other paleocontinents, and to assess the potential for the Africa...

We describe the first occurrence of biogenic traces made by mammals within an iron formation cave located in the Serra da Ferrugem Ridge, in Southeastern Brazil. These bioerosions are tooth traces produced in boulders, walls and floor within the cave. The traces occur as sets of two or more grooves, which are highly variable in size. The grooves...

We present a systematic revision of the ‘prosauropod’ dinosaur Unaysaurus tolentinoi. Past phylogenetic treatments of this taxon have presented it as a key constituent of the low-diversity Plateosauridae. This clade, along with Massospondylidae, is currently regarded as a relatively non-controversial example of monophyly within non-sauropodan sauro...

The Late Triassic (Carnian) upper Santa Maria Formation of south Brazil has yielded some of the oldest unequivocal records of dinosaurs. Here, we describe a new saurischian dinosaur from this formation, Nhandumirim waldsangae, gen. et sp. nov., based on a semiarticulated skeleton, including trunk, sacral, and caudal vertebrae, one chevron, right il...

Fossils and modes of fossil preservation in caves within the Vazante-Paracatu-Unai carstic realm.

Este trabalho tem por objetivo apresentar o potencial dos geossistemas ferruginosos de Minas Gerais, Brasil, para a prática do geoturismo e da educação patrimonial. Foi realizada uma seleção e avaliação de geossítios representativos do geopatrimônio com base no seu potencial geoturístico. Essa avaliação está baseada no levantamento dos geossítios n...

Sacisaurus agudoensis is the only silesaurid known from the Triassic beds of the Santa Maria Supersequence and the correlation of its type locality to the other Triassic deposits of south Brazil has always been controversial. In an attempt to improve this, a handful of dinosaur and cynodont remains found associated to S. agudoensis are here describ...

New specimens of the clam shrimp ‘Pseudestheria’ abaetensis Cardoso, 1971 (Spinicaudata) are described. The material was collected from the Quiricó Formation (Lower Cretaceous of the Sanfranciscana Basin), at the same locality as the type series of the species. The carapaces are very large, oval and elongated, with anteriorly located and slightly p...

The evolutionary history of dinosaurs might date back to the fist stages of the Triassic (c. 250– 240 Ma), but the oldest unequivocal records of the group come from Late Triassic (Carnian – c. 230 Ma) rocks of South America. Here, we present the fist braincase endocast of a Carnian dinosaur, the sauropodomorph Saturnalia tupiniquim, and provide new...

The evolutionary history of dinosaurs might date back to the first stages of the Triassic (c. 250–240 Ma), but the oldest unequivocal records of the group come from Late Triassic (Carnian – c. 230 Ma) rocks of South America. Here, we present the first braincase endocast of a Carnian dinosaur, the sauropodomorph Saturnalia tupiniquim, and provide ne...

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...

O registro fóssil dos depósitos sedimentares proterozoicos, paleozoicos e mesozoicos do Cráton do São Francisco inclui estruturas de origem microbiana (microbialitos, oncólitos), palinomorfos terrestres e marinhos, microfósseis silicosos e carbonáticos de origem marinha, metazoários neoproterozoicos, artrópodes, uma variedade de bioturbações, verte...

A Era Mesozoica é um período fascinante para a evolução da vida na Terra. Diversos grupos com representantes na fauna atual, como os lissanfíbios, mamíferos, aves, tartarugas, lagartos, serpentes e crocodilos surgiram e se diversificaram nessa era. Os dinossauros e pterossauros também ocorrem nesse intervalo do tempo geológico, tornando-o conhecido...

Lewisuchus admixtus is an enigmatic early dinosauriform from the Chañares Formation, Ladinian of Argentina, which has been recently considered a member of Silesauridae. Yet, it differs markedly from Late Triassic silesaurids in dental and vertebral anatomy. Indeed, a detailed redescription of its holotype allowed the identification of several featu...

Ichnological evidence suggests that dinosauromorphs originated by the Early Triassic, and skeletal remains of non-dinosaur representatives of the clade occur from the Anisian to the end of the Triassic. These taxa are small-to medium-sized, vary in feeding and locomotor features, and occurred over most of western Pangaea. They include the small lag...

This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the cont...

This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the cont...

This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the cont...

Post-Triassic theropod, sauropodomorph, and ornithischian dinosaurs are readily recognized based on the set of traits that typically characterize each of these groups. On the contrary, most of the early members of those lineages lack such specializations, but share a range of generalized traits also seen in more basal dinosauromorphs. Here, we repo...

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 fra...

The dinosaur record of the Santa Maria beds of Rio Grande do Sul (Mid Late Triassic; south Brazil) includes the herrerasaur Staurikosaurus pricei, and two basal members of the sauropodomorph lineage: Saturnalia tupiniquim and Unaysaurus tolentinoi. The most enigmatic of the saurischian taxa is, however, Guaibasaurus candelariensis, previously regar...

The oldest unequivocal records of Dinosauria were unearthed from Late Triassic rocks (approximately 230 Ma) accumulated over extensional rift basins in southwestern Pangea. The better known of these are Herrerasaurus ischigualastensis, Pisanosaurus mertii, Eoraptor lunensis, and Panphagia protos from the Ischigualasto Formation, Argentina, and Stau...

We redescribe the holotype of the saurischian dinosaur Staurikosaurus pricei Colbert, 1970 from Late Triassic Santa Maria Formation (southern Brazil), following additional preparation that revealed new anatomical features. A revised diagnosis is proposed and the published synapomorphies for Dinosauria and less inclusive clades (e.g. Saurischia) are...

We redescribe the holotype of the saurischian dinosaur Staurikosaurus pricei Colbert, 1970 from Late Triassic Santa Maria Formation (southern Brazil), following additional preparation that revealed new anatomical features. A revised diagnosis is proposed and the published synapomorphies for Dinosauria and less inclusive clades (e.g. Saurischia) are...

FIGURE 8. Photograph and drawing of cervical and dorsal vertebrae embedded within sediment along with the left femur, in right lateral view. Abbreviations: c 5 – c 9, presumed cervical vertebrae 5 to 9; d 1 – d 8, dorsal vertebrae 1 to 8; f, femur. Scale bar = 8 cm.

FIGURE 13. Photographs and drawings of the third sacral vertebra in cranial (a – b) and caudal (c – d) views. Abbreviations: lpr, lateral process; tp, transverse process. Scale bar = 2 cm.

FIGURE 26. Photographs of the right femur in proximal (a) and distal (b) views, the proximal part of the left femur that is attached to vertebral column (see Fig. 8) in laterocaudal view (c), and the isolated distal part of the left femur in lateral view (d). Abbreviations: fccs, craniocaudal sulcus on the dorsal surface of the femoral head; ffic,...

FIGURE 28. Photographs of the right tibia in medial (a), cranial (b), caudal (c) and lateral (d) views; the left tibia in medial view (e), and the right tibia in proximal (f) and distal (g) views. Abbreviations: af, articular facet for the ascending process of the astragalus; cls, craniolateral sulcus; cms, craniomedial sulcus; cn, cnemial crest; c...

FIGURE 1. Staurikosaurus pricei, skeletal reconstruction, (based upon MCZ 1669, holotype), depicting the preserved bones. After Novas (1997). Scale bar = 20 cm.

FIGURE 2. Photographs and drawings of the left mandibular ramus in lateral (a, b) and medial (c, d) views. Abbreviations: adf, adductor fossa; an, angular; ar, articular; d, dentary; df, dentary furrow; frm, foramen; pra, prearticular; sa, surangular; spl, splenial; t 1 – t 15, preserved teeth or fragments of teeth numbered sequentially beginning a...

FIGURE 3. Photographs and drawings of the left mandibular ramus in dorsal (a, b) and ventral (c, d) views. Abbreviations: an, angular; ar, articular; d, dentary; emf, external mandibular fenestra; mac, mandibular canal; pra, prearticular; sa, surangular; spl, splenial. Scale bar = 6 cm.

FIGURE 11. Photographs and drawings of the second sacral vertebra in cranial (a – b) and caudal (c – d) views. Abbreviations: crls, craniolateral sulcus; lcpl, lateral concavity on the lateral process; lpr, lateral process; mclp, medial concavity on the lateral process; ns, neural spine; prz, prezygapophysis; poz, postzygapophysis; sprzl, spinoprez...

FIGURE 19. Photographs and drawings of distal caudal vertebrae in ventral view, sequence 5 (a – b) and detail of the caudal vertebrae of sequence 3 (c). Scale bar for (a – b) = 6 cm; (c) = 2 cm.

FIGURE 21. Photograph and drawing of the left ilium associated with the vertebral column, in lateral view (a – b), and the right ilium in lateral view (c – d). Abbreviations: ant, antitrochanter; caic, caudal iliac concavity; cric, cranial iliac concavity; isp, ischial peduncle; prap, preacetabular process; prac, preacetabular crest; pup, pubic ped...

FIGURE 27. Photographs and drawings of the right (a – b) and left (c – d) proximal femora in cranial view. Abbreviations: artef, artefactual shelf; fclc (fgt), femoral craniolateral crest, part of the “ greater ” trochanter; fcmc, femoral craniomedial crest. Scale bars = 2 cm.

FIGURE 31. Photographs of an undetermined bone, initially described as the right humerus by Colbert (1970). Undetermined orientations. Scale bar = 2 cm.

FIGURE 33. Cladograms showing the alternative phylogenetic positions of Staurikosaurus pricei and Herrerasauridae: (a) based upon reanalysis of the dataset of Rauhut (2003), showing S. pricei as a theropod; (b) based upon reanalysis of the dataset of Langer & Benton (2006), showing S. pricei as a basal saurischian. The black circle on cladogram (a)...

FIGURE 4. Photographs of the right mandibular ramus in medial (a) and lateral (b) views. Photographs of the left mandibular ramus in lateral view (c) demonstrating the morphology of the 8 th tooth and details of the serrated carina. Abbreviations: adf, adductor fossa; an, angular; d, dentary; emf, external mandibular fenestra; pra, prearticular; sa...

FIGURE 5. Photographs and drawings of the fourth cervical vertebra in left (a – b) and right (c – d) lateral views. Abbreviations: caf, caudal fossa; crf, cranial fossa; ipoe, infrapostzygapophyseal excavation; ns, neural spine; pa, parapophysis; podl, postzygodiapophyseal lamina; poz, postzygapophysis; prdl, prezygodiapophyseal lamina; prz, prezyg...

FIGURE 7. Photographs and drawings of the presumed fourth cervical vertebra in cranial (a – b) and caudal (c – d) views. Abbreviations: caaf, caudal articular facet of centrum; ccaf, cranial articular facet of centrum; itpos, interpostzygapophyseal sulcus; nc, neural canal; ns, neural spine; pa, parapophysis; poz, postzygapophysis; prz, prezygapoph...

FIGURE 9. Photographs of dorsal vertebrae 9 – 11 in right lateral view (a) and the centrum of the 12 th dorsal vertebra (b) in cranial view. Abbreviations: d 9 – d 11, dorsal vertebrae 9 to 11. Scale bar = 2.5 cm.

FIGURE 12. Photographs and drawings of the third sacral vertebra in left lateral (a – b), dorsal (c – d) and ventral (e – f) views. Abbreviations: asi, articular surface for ilium; lpr, lateral process; prz, prezygapophysis; tp, transverse process. Scale bar = 2 cm.

FIGURE 14. Photographs of the third sacral (a) and the first caudal vertebrae (b) in right lateral view. Scale bar for (a) = 2 cm; (b) = 2.5 cm.

FIGURE 18. Photographs and drawings of the distal caudal vertebrae, sequence 5 (a – b) and sequence 6 (c – d), in right lateral view. Abbreviation: zp, zygapophysis. Scale bar = 6 cm.

FIGURE 24. Photographs and drawings of the left ischium in lateral (a – b) and medial (c – d) views and the right ischium (e – f) in lateral view. Abbreviations: ciex, caudal ischial excavation; cipr, caudal ischial process; ia, ischial axis; iop, ischial obturator plate. Scale bar = 6 cm.

FIGURE 29. Photographs of the left fibula in cranial (a), caudal (b), proximal (e) and distal (f) views, and the right fibula in lateral (c) and medial (f) views. Scale bar for (a – d) = 8 cm; (e – f) = 2 cm.

FIGURE 32. Undetermined bone fragments. Scale bar = 5 cm.

FIGURE 6. Photographs and drawings of the presumed fourth cervical vertebra in ventral (a – b) and dorsal (c – d) views. Abbreviations: ep, epipophysis; ns, neural spine; pa, parapophysis; poz, postzygapophysis; prz, prezygapophysis; tp, transverse process; vk, median ventral keel. Scale bar = 3 cm.

FIGURE 10. Photographs and drawings of the caudal dorsal vertebrae in right lateral view, associated with the first sacral and the left ilium (a – b), and detail of the 8 th dorsal vertebra in left lateral view (c – d). The miniature photo (e) marks the region of the block detailed in (c – d) (see also Fig. 8). Abbreviations: ccdl, caudal centrodia...

FIGURE 15. Photographs of the second caudal vertebra in dorsal (a) and ventral (b) views, and the third caudal vertebra in right lateral (c) and caudal views (d). Scale bars = 2 cm.

FIGURE 16. Photographs of the fourth caudal vertebra in right lateral (a), caudal vertebrae, sequence 1 (b) in left lateral view, and caudal vertebrae, sequence 2 (c) in right lateral view. Scale bar for (a) = 2 cm; (b – c) = 3 cm.

FIGURE 17. Photographs and drawings of six distal caudal vertebrae, sequence 3, in right lateral view (a – b), and seven distal caudal vertebrae, sequence 4, in left lateral view (c – d). Abbreviations: prz, prezygapophysis; tp, transverse process. Scale bar for (a – b) = 5 cm; (c – d) = 6 cm.

FIGURE 20. Photographs of the left scapula in lateral (a) and distal (b) views. Scale bar = 1 cm.

FIGURE 23. Photographs and drawings of the left pubis in lateral (a – b) and medial (c – d) views. Abbreviations: b, distinct bevel on distal end of pubic; pdex, distal expansion of pubis. Scale bar = 6 cm.

FIGURE 25. Photographs of the right femur in cranial (a), medial (b), caudal (c), and lateral views (d). Abbreviations: calc, caudolateral crest; f 4 t, femoral fourth trochanter; ffic, femoral fibular condyle; fclc, femoral craniolateral crest; fh, femoral head; ftic, femoral tibial condyle. Scale bar = 7 cm.

FIGURE 30. Photographs and drawings of the left fibula in lateral (a – b) and medial (c – d) views. Abbreviations: fms, fibular medial sulcus; ifi, insertion of the ilifibularis muscle; mis, scar for muscular insertion. Scale bar = 8 cm.

Besides being rare, most theropod remains from fossil deposits of Brazil are incomplete. Up to date the Romualdo Member (Aptian/Albian) of the Santana Formation yielded six theropod specimens. To those we add the description of a sequence of three posterior sacral and six anterior caudal vertebrae with three chevrons (MN 4743-V). Differences betwee...