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New evidence of putative Unenlagiinae (Deinonychosauria, Theropoda) in the São Luís-Grajaú Basin, Albian–Cenomanian, State of Maranhão, Brazil. We studied an assemblage of teeth from Laje do Coringa, São Luís-Grajaú Basin, Alcântara Formation, State of Maranhão, Brazil. The collection sites are dated as Albian–Cenomanian. Ten teeth were submitted to morphological analysis in Scanning Electron Microscopy, with the goal of identifying materials likely associated with unenlagiine theropod dinosaurs. Three specimens were identified as putative members of the group based on: (a) strong labial-lingual flattening of the crown, (b) absence of longitudinal grooves, (c) dimensions compatible with previously described Unenlagiinae, (d) “ziphodont” morphology lightly to the mesial portion, (e) basal section with two distinguishable borders, (f) complete absence of serrations. These teeth expand chronological and geographical distributions of Unenlagiinae dinosaurs. Keywords: Dinosauria, teeth, Maniraptoriformes, Cretaceous. RESUMO – O presente trabalho investiga uma associação de dentes isolados provenientes da Laje do Coringa, Bacia São Luís-Grajaú, Formação Alcântara, Estado do Maranhão, Brasil. Os locais de coleta são datados para os andares Albiano–Cenomaniano do Período Cretáceo. Dez dentes foram submetidos a análises morfológicas em Microscopia Eletrônica de Varredura, com objetivo de identificar materiais possivelmente associáveis a dinossauros terópodos unenlagiinos. Três espécimes foram identificados como possivelmente associáveis ao grupo, com base em (a) forte achatamento lábio-lingual da coroa, (b) ausência de estrias longitudinais, (c) dimensões totais dos espécimes compatíveis com as equivalentes de Unenlagiinae previamente descritos, (d) forma “zifodonte” levemente voltada para a porção mesial, (e) forma da seção basal com duas bordas distinguíveis, (f) ausência completa de serrilhas. Estes dentes ampliam distribuições cronológicas e geográficas de dinossauros Unenlagiinae. Palavras-chave: Dinosauria, dentes, Maniraptoriformes, Cretáceo.

A paleoparasitological investigation was carried out on Crocodyliformes coprolites discovered in the Municipality of Santo Anastacio, in the southwestern region of the State of Sao Paulo. Individual samples were extracted from the surface and internal portion of each coprolite which revealed the presence of thick-shelled parasite eggs in three of them. The morphological characteristics of the specimens, i.e., rounded or oval shape, thick-shelled with mammillated surface, as well as their size, suggest that these eggs belong to the superfamily Ascaridoidea, which are gastrointestinal parasite nematodes of vertebrates, popularly known as “roundworms”. This is the first record of Ascaridoidea eggs discovered in Crocodyliformes hosts from the Upper Cretaceous of Brazil.

Synapsids were able to adopt different gaits, including half–bounding and bipedal skipping, since the Early Jurassic, as indicated by a large record of fossil footprints, found in hyper-arid erg–dominated paleonvironments from South and North America. The mammaliamorph origin of these footprints is corroborated by their shape, stance, and gait, in a large number of trackway specimens from the Parana Basin (Botucatu Formation) of Brazil. This record is interpreted as the expression of the locomotor skills of a single trackmaker population, and might be grouped together under a pre-existing ichnotaxonomic label, Brasilichnium elusivum Leonardi, 1981, including one of the few unambiguous Mesozoic records of bipedal saltatory gait in synapsids. This bipedal saltatory gait is associated with desert paleoenvironments, and more specifically with sand dunes with little or no vegetation cover. Decades of collecting has resulted in one of the largest records of synapsid footprints worldwide, and ichnology has proven fundamental to investigate elusive aspects of their natural history.

Made available in DSpace on 2021-06-25T11:01:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01. Added 1 bitstream(s) on 2021-07-15T14:35:59Z : No. of bitstreams: 1 S0001-37652021000401205.pdf: 5311061 bytes, checksum: 06ed2fd3ad73c02f667cd32b22587292 (MD5) A paleoparasitological analysis was carried out on a large coprolite assigned to a carnivoran mammal, recovered from the Municipality of Uruguaiana, in the western region of the State of Rio Grande do Sul, Brazil, where the Upper Pleistocene Touro Passo Formation crops out. For this, an individual sample was extracted from the specimen using an electric drill, dissociated with 10% hydrochloric acid solution, washed with distilled water, and sifted through a 500 mesh Tyler sieve. After laboratory processing, the sediment retained on the sieve was mixed with glycerin and examined by optical microscopy, which revealed the presence of 14 protozoan oocysts and three nematode eggs. The morphological characteristics of the oocysts (i.e., spherical shape, thick-walled, internal zygote apparently at the beginning of sporulation, as well as their size) and of the eggs (i.e., ovoidal shape, rounded ends, smooth surface, thin-shelled, embryo in their interior, along with their morphometry) suggest that these specimens belong respectively to the orders Eucoccidiorida and Strongylida (Family Ancylostomatidae) represented by several parasitic species of the alimentary tract of modern carnivore. This is the first record of paleoparasites discovered in a vertebrate host from the Touro Passo Formation. UNESP Núcleo de Evolução e Paleobiologia de Vertebrados Departamento de Geologia Aplicada Instituto de Geociências e Ciências Exatas, Campus Rio Claro, Av. 24 A, 1515 Instituto Adolfo Lutz Núcleo de Ciências Biomédicas CLR II, R. Rubens Arruda, Q6 Universidade Federal do Rio Grande do Sul Programa de Pós-Graduação em Geociências Instituto de Geociências UFRGS, Av. Bento Gonçalves, 9500 Universidade Federal do Rio Grande (FURG) Laboratório de Geologia e Paleontologia Instituto de Oceanografia, Av. Itália, Km 8 UNESP Núcleo de Evolução e Paleobiologia de Vertebrados Departamento de Geologia Aplicada Instituto de Geociências e Ciências Exatas, Campus Rio Claro, Av. 24 A, 1515

Made available in DSpace on 2019-10-06T16:49:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01. Added 1 bitstream(s) on 2019-10-09T18:35:38Z : No. of bitstreams: 1 S0001-37652019000400508.pdf: 2788820 bytes, checksum: 62cf24a2ab93abbe5b24a0dc6073b2e3 (MD5) This study presents the oldest record of Acanthocephala parasite eggs in coprolites preliminary assigned to Crocodyliformes, recovered in the region of Santo Anastácio Municipality, Southwestern São Paulo State. For this, a paleoparasitological investigation was carried out on 53 mineralized coprolites ( complete or fragmented), with round shape or cylindrical shape of rounded or pointed ends, 0.2 - 3.9 cm in length x 0.1 - 2.4 cm in diameter, 3.7 grams in weight, and absence of food remains. Individual samples of the surface and internal portions of each coprolite were extracted by electric drill, dissociated with Cloridic Acid 10% solution, washed with Distilled Water, and filtered in granulometric screen Mesh / Tyler 325. After laboratory processing, the sediments retained on the granulometric screen was studied with Glycerin under optical microscopy, and the presence of four Acanthocephala eggs could be observed in sample of only one of these ichnofossils. All specimens were well preserved and showed 72.5 - 85 µm in length x 27.5 - 50 µm in width, elliptical shape, three concentric and thick shells, and embryos in their interior. This study inaugurates investigations and knowledge about Paleoparasitology in Crocodyliformes coprolites from the Bauru Group, Upper Cretaceous from the Paraná Basin. Núcleo de Evolução e Paleobiologia de Vertebrados, Departamento de Geologia Aplicada, Instituto de Geociências e Ciências Exatas, UNESP, Campus Rio Claro. Av. 24 A, 1515, 13506-900 Rio Claro, SP, Brazil

Made available in DSpace on 2019-10-04T12:37:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-02-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The Bauru Group has three crocodyliform taxa: Itasuchus, Pepesuchus and Barreirosuchus. Within these taxa, the skulls of Itasuchus jesuinoi and Barreirosuchus franciscoi are fragmentary and have no described postcranial material, hindering the comparison with other specimens with known taxonomic positions. Thus, the taxonomic placement of I. jesuinoi and B. franciscoi remains unsolved. Additionally, although the Marilia Formation has been dated to the Maastrichtian Age, the chronology of the Adamantina Formation is up for debate. New material found in the Adamantina Formation, referred to Pepesuchus, is described. Phylogenetic analysis returned a supported clade composed of Itasuchus, Pepesuchus and Barreirosuchus, here named Pepesuchinae. Pepesuchinae is a sister clade to Peirosaurinae, a clade grouping Peirosaurus, Uberabasuchus, Montealtosuchus and Hamadasuchus. The calibrated cladogram dates the origin of the Bauru Group to the early Santonian, and the morphological similarity between the taxa from the Adamantina and Marilia formations makes it possible to infer a Campanian-Maastrichtian age for the Adamantina Formation. Univ Estadual Paulista, Inst Geociencias & Ciencias Exatas, Posgrad Geol Reg, Nucleo Evolucao & Paleobiol Vertebrados, Campus Rio Claro,Av 24 A-1515, BR-13506900 Rio Claro, SP, Brazil Univ Estadual Paulista, Inst Geociencias & Ciencias Exatas, Posgrad Geol Reg, Nucleo Evolucao & Paleobiol Vertebrados, Campus Rio Claro,Av 24 A-1515, BR-13506900 Rio Claro, SP, Brazil CNPq: 141177/2011-0

Made available in DSpace on 2019-10-06T16:36:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-10-01 Two new ascaridoid species, Bauruascaris cretacicus n. gen. et n. sp., and Bauruascaris adamantinensis n. gen. et n. sp., are described based on the fossils of eggs preserved in 80–70 million year old phosphatized coprolites of Crocodyliformes, chronologically assigned to the Upper Cretaceous (Campanian/Maastrichtian age), collected from sedimentary rocks of the Bauru Group, Adamantina Formation in the municipality of Santo Anastácio, in the southwestern region of the state of São Paulo, Brazil, South America. This paper describes the oldest ascaridoid species ever recorded in Crocodylomorpha. Hence, this article contributes to the body of knowledge about the evolutionary history of this nematode group. It also offers a clue about the composition of the parasite fauna of these reptiles from the Late Cretaceous, which is still unknown despite numerous studies about various aspects of their biology and the pioneering paleoparasitological analysis of animal coprolites by South American researchers. Núcleo de Evolução e Paleobiologia de Vertebrados Departamento de Geologia Aplicada Instituto de Geociências e Ciências Exatas Universidade Estadual Paulista UNESP, Campus Rio Claro, Avenida 24 A/1515, Jardim Bela Vista Núcleo de Evolução e Paleobiologia de Vertebrados Departamento de Geologia Aplicada Instituto de Geociências e Ciências Exatas Universidade Estadual Paulista UNESP, Campus Rio Claro, Avenida 24 A/1515, Jardim Bela Vista

Made available in DSpace on 2018-12-11T16:46:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-07-03 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) A new ichnospecies, Brasilichnium anaiti, is erected on material from the Botucatu Formation of Brazil. The general morphology supports ichnotaxonomic similarity between the new ichnotaxon and Brasilichnium elusivum Leonardi, 1981, even if a separation at the ichnospecies level is evident, based on differences in shape and arrangement of pes digit marks along with a clear dimensional gap between both ichnotaxa. Similar forms from the Lower Jurassic of the United States are known and should be included under this new ichnotaxonomic label, based on shared morphological features. B. anaiti is constantly associated with B. elusivum in dune foresets of hyperarid paleoenvironments, to which these forms are restricted. This makes B. anaiti a further element of the Brasilichnium ichnocoenosis in the larger framework of the Chelichnus ichnofacies. Re–evaluation of possible trackmakers highlights the difficulties of unequivocal referring this ichnotaxon to a specific producer, but restrains potential trackmakers to early mammaliamorph therapsids. Department of Biology Faculty of Sciences and Letters of Ribeirão Preto Univeristy of São Paulo Center for Vertebrate Evolution and Paleobiology Department of Applied Geology Institute of Geosciences and Exact Sciences São Paulo State University (UNESP) Center for Vertebrate Evolution and Paleobiology Department of Applied Geology Institute of Geosciences and Exact Sciences São Paulo State University (UNESP) FAPESP: 2013/01930–1

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:51:48Z No. of bitstreams: 1 S0001-37652011000400006.pdf: 3392538 bytes, checksum: 3fe404a6c65cb6527e8c012cc85b0c4b (MD5) Made available in DSpace on 2013-08-22T18:51:48Z (GMT). No. of bitstreams: 1 S0001-37652011000400006.pdf: 3392538 bytes, checksum: 3fe404a6c65cb6527e8c012cc85b0c4b (MD5) Previous issue date: 2011-12-01 Made available in DSpace on 2013-09-30T19:42:50Z (GMT). No. of bitstreams: 2 S0001-37652011000400006.pdf: 3392538 bytes, checksum: 3fe404a6c65cb6527e8c012cc85b0c4b (MD5) S0001-37652011000400006.pdf.txt: 41953 bytes, checksum: e3255f994f783a78fa10f86417c60272 (MD5) Previous issue date: 2011-12-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T14:16:54Z No. of bitstreams: 2 S0001-37652011000400006.pdf: 3392538 bytes, checksum: 3fe404a6c65cb6527e8c012cc85b0c4b (MD5) S0001-37652011000400006.pdf.txt: 41953 bytes, checksum: e3255f994f783a78fa10f86417c60272 (MD5) Made available in DSpace on 2014-05-20T14:16:54Z (GMT). No. of bitstreams: 2 S0001-37652011000400006.pdf: 3392538 bytes, checksum: 3fe404a6c65cb6527e8c012cc85b0c4b (MD5) S0001-37652011000400006.pdf.txt: 41953 bytes, checksum: e3255f994f783a78fa10f86417c60272 (MD5) Previous issue date: 2011-12-01 Petrobras Universidade Estadual Paulista (UNESP) Universidade Federal do Maranhao (UFMA) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) A Formação Alcântara, uma importante unidade estratigráfica do início do Cenomaniano no Brasil, foi depositada sob condições transicionais (estuarinas), e o seu registro fóssil inclui restos fragmentários de vegetais, peixes, crocodilomorfos, pterossauros e dinossauros, com uma notável diversidade de placas dentárias de dipnoiformes. O material de dipnoiformes aqui reportado compreende um novo taxon, Equinoxiodus alcantarensis gen. et sp. nov. A maioria dos morfótipos de vertebrados continentais coletados na Formação Alcântara são similares a faunas cronocorrelatas do norte da África, mas este novo gênero de Dipnoiformes indica algum grau de isolamento paleogeográfico e endemismo, provavelmente causado pelo alargamento do Oceano Atlântico equatorial no início do Cenomaniano, que pode ter afetado, de forma seletiva, algumas espécies. The Alcântara Formation, an important stratigraphic unit from the early Cenomanian of Brazil, was deposited under transitional (estuarine) conditions, and its fossil record includes fragmentary remains of plants, fishes, crocodylomorphs, pterosaurs and dinosaurs, with a noteworthy diversity of dipnoiformes tooth plates. The dipnoiformes material reported here comprises a new taxon, Equinoxiodus alcantarensis, gen. et sp. nov. Most of the identified morphotypes of continental vertebrates collected in the Alcântara Formation are similar to chronocorrelative faunas from Northern Africa, but this new genus of Dipnoiformes indicates some degree of paleogeographic isolation and endemism. This was probably caused by the widening of the equatorial Atlantic Ocean during the early Cenomanian, which may have selectively affected some species. USP IGC GSA UEMA CECEN Universidade Federal do Maranhão Departamento de Biologia UNESP IGCE DGA UNESP IGCE DGA

Since the description of Sphagesaurus, mostly dental material has been reported, apart from two incomplete skulls. Here we describe a new species of Sphagesaurus, from Monte Alto City, Southeastern...

A noteworthy diversity of Dipnoi tooth plates has been collected in the fossiliferous conglomerates of the Alcântara Formation, early Cenomanian (Cretaceous) of Brazil. This sequence was deposited under transitional (estuarine) conditions, gathering reworked dissociated fossils represented by plants, fishes, crocodylomorphs, pterosaurs and dinosaurs. A new species of Dipnoi is reported in this work, Equinoxiodus schultzei sp. nov. whose genus is endemic of northern South America and lived probably in fresh water. The presence of several species of dipnoan in the mid-Cretaceous of north/northeastern Brazil indicates that the environmental conditions were very suitable to this group, confirming the well-marked seasonality of the climate, with frequent prolonged droughts, as interpreted in previous publications.

Although the State of Goias contains significant areas of potentially fossiliferous sedimentary deposits, the vertebrate fossil record in the state has not been properly explored, especially with respect to mammals. This work brings together information on fossil and sub-fossil occurrences of mammal in Goias from near the Pleistocene/Holocene boundary gathered from bibliographic references and Brazilian collections. Abundant Pleistocene surface cover may be found, commonly in interfluvial areas between major rivers. From some of these areas, as in Goiânia and Niquelândia municipalities, an important amount of Pleistocene megafauna remains have been reported. Caves in Goias also exhibit a great number of vertebrates records of the following families: Didelphidae, Dasypodidae, Phyllostomidae, Natalidae, Vespertilionidae, Procyonidae, Tayassuidae, Cervidae, Cuniculidae, Dasyproctidae, Echimyidae, Cricetidae and indeterminant Chiroptera. Moreover, archaeological studies in Serranopolis Municipality have rendered a vast biotic variety, including fishes, amphibians, reptiles, birds and mammals from near the Pleistocene/Holocene boundary. Among these remains the following mammal families were recognized: Felidae, Canidae, Mustelidae, Mephitidae, Myrmecophagidae, Hydrochoeridae, Erethizontidae, Caviidae, Atelidae, Cebidae and Tapiridae. Thus, the rich and varied fossil record from near the Pleistocene/Holocene boundary in Goias has a great potential to furnish important palaeobiogeography, palaeoenvironmental and palaeoclimatic data and a better knowledge of the evolution of the Cerrado and its mammalian fossil assemblage during this period.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2014-02-26T17:23:56Z No. of bitstreams: 1 WOS000234128300004.pdf: 497489 bytes, checksum: b38725453b7d7f9d19699523a6c6f20f (MD5) Made available in DSpace on 2014-02-26T17:23:56Z (GMT). No. of bitstreams: 1 WOS000234128300004.pdf: 497489 bytes, checksum: b38725453b7d7f9d19699523a6c6f20f (MD5) Previous issue date: 2006-01-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:23:09Z No. of bitstreams: 1 WOS000234128300004.pdf: 497489 bytes, checksum: b38725453b7d7f9d19699523a6c6f20f (MD5) Made available in DSpace on 2014-05-20T15:23:09Z (GMT). No. of bitstreams: 1 WOS000234128300004.pdf: 497489 bytes, checksum: b38725453b7d7f9d19699523a6c6f20f (MD5) Previous issue date: 2006-01-01 Material from a new titanosaur from the Bauru Basin (Bauru Group), Brazil is described and compared with well-known titanosaurs. Adamantisaurus mezzalirai gen. et sp. nov. is based on six articulated anterior caudal vertebrae and two haemapophyses collected from the Adamantina Formation, which is considered to be Campanian-Maastrichtian? in age. Adamantisaurus mezzalirai is characterized by the following combination of characteristics: anterior caudal vertebrae with straight or slightly backwardly-projecting neural spines with strongly expanded distal ends, stout prespinal lamina, very wide pre- and postzygapophyseal articular facets, and concave postzygapophyseal articular facets on anterior caudal vertebrae. Although our cladistic analysis has produced equivocal results, Adamantisaurus mezzalirai shares with DGM 'Series B' (Peiropolis titanosaur) and Aeolosaurus the presence of postzygapophyses with concave articular facets, and shares with DGM 'Series B' the presence of laterally expanded neural spines and stout prespinal lamina. Additionally, A. mezzalirai shares with DGM 'Series' C (other titanosaur from Peiropolis) the presence of short neural spines. São Paulo State Univ, UNESP, IGCE, BR-13506900 Rio Claro, Brazil São Paulo State Univ, UNESP, IGCE, BR-13506900 Rio Claro, Brazil

The Adamantina Formation (Bauru Group), between Lucelia and Irapuru municipalities (northwestern Sao Paulo State, southeastern Brazil), has been in the last years a very important area for collecting Upper Cretaceous fossil vertebrates. So far, the main groups recovered include Testudines, Crocodyliformes and Dinosauria (Theropoda and Titanosauria). The fossil material is usually disarticulated and fragmented and was collected from very fine-grained sandstones, with muddy matrix and cross-stratification and lamination. Testudines are represented by fragments of carapaces and plastrons. Crocodyliformes are composed only of fragmented osteological remains and isolated teeth. Maniraptora is especially represented by isolated teeth, allowing the identification of the Dromaeosaurinae, Velociraptorinae and Troodontidae clades, in addition to some probable endemic groups. Titanosauria is the most representative and abundant group in these fossil localities, however materials are mainly fragments of ribs and some appendicular bones, without diagnostic osteological elements, like caudal vertebrae. The lithological characteristics of the outcrops suggest a paleoenvironment of braided rivers, in an arid climate, with few vegetation cover.

Made available in DSpace on 2014-10-01T13:08:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-08-01Bitstream added on 2014-10-01T14:03:46Z : No. of bitstreams: 1 S1982-45132013000200014.pdf: 3068422 bytes, checksum: 12b8261dc0f61c5e7cc2df07f7e13386 (MD5) O município de Uberaba apresenta grande potencialidade geoturística quando considerado aos seus patrimônios geológicos. As rochas ígneas da Formação Serra Geral são encontradas em 12 atrativos geoturísticos, com destaque para as cachoeiras de Ponte Alta (40 metros de altura) e Peirópolis III (sete metros de altura). As rochas sedimentares da Formação Uberaba foram descritas em 11 pontos, destacando-se Cachoeira e Gruta do Giovane (doze metros de altura). Nas rochas sedimentares da Formação Marília destaca-se o afloramento da Caieira (gruta de três metros com estalactites e estalagmites) e a Cachoeira do Vale Encantado (oito metros de altura), entre outros 8 locais. Após o levantamento da geodiversidade foi realizado um diagnóstico ambiental nos potenciais atrativos geoturísticos, sendo utilizado o Método Visitor Impact Management. Os resultados indicam que somente a Cachoeira do Vale Encantado apresenta impacto moderado, o menor quando comparado aos 22 sítios com impacto alto ou preocupante, e 7 com impacto muito alto. Além de definir as estratégias de manejo e monitoramento dos indicadores de impacto ambiental, o presente trabalho serve de base para que as atividades do potencial Geoparque de Uberaba (MG) sejam realizadas com responsabilidade ambiental e/ou geoconservação. Uberaba municipality, Western Minas Gerais State, has a great geotouristic potential, regarding its geological heritage. The igneous rocks from Serra Geral Formation are found in 12 points, highlighting Ponte Alta (40 meters) and Peirópolis III (7 meters) waterfalls. The sedimentary rocks from Uberaba Formation were described in 11 points, especially Giovane Cave and Waterfall (12 meters). In Marilia Formation sedimentary rocks, the Caieira outcrop (three-meter cave with stalactites and stalagmites) and Vale Encantado Waterfall (8 meters) can be pointed out, among other 8 spots. After the geodiversity assessment, an environmental diagnosis was conducted throughout the potential geotourism attractions, by using the Visitor Impact Management Method. The results indicate that only Vale Encantado Waterfall presents a moderate impact, the least when compared to 22 other sites, exhibiting high or worrisome impact, and 7 with very high impact. In addition to setting the management strategies, and monitoring the environmental impact indicators, this work provides the basis so that activities in the potential Geopark of Uberaba (MG) can be conducted with environmental responsibility and / or geoconservation. UNESP IGCE UNIFAL Instituto de Ciência e Tecnologia UNESP IGCE Depto. de Geologia Aplicada UNESP IGCE Deplan UNESP IGCE UNESP IGCE Depto. de Geologia Aplicada UNESP IGCE Deplan

Among taxons of Crocodyliformes from the Bauru Group (Late Cretaceous), a large number of morphotypes, including cranial and post-cranial materials, have been described associated with Baurusuchus pachecoi. However, the lack of ontogenetic studies, similar to what has been done with Mariliasuchus amarali, has led to the allocation of new genera and species to the few complete skulls found. The present contribution provides the description of a juvenile specimen of Baurusuchidae, housed in the collection of the "Museu de Ciencias da Terra", Rio de Janeiro, under the number MCT 1724 - R. It is composed of rostrum and mandible, associated and in occlusion, with the left side better preserved than the right one, with extremely reduced ziphodont dentition. The fossil is 125.3 mm in preserved length from the anterior edge of the premaxilla to the posterior end of the dentary; 117.5 mm in preserved length from premaxilla to palatines; and 51.4 mm in lateral height. Among the ontogenetic aspects observed are faint ornamentation, consisting of very separated, large vermiform grooves, a straighter maxillary ventral line, dentary slightly dorsally inclined, mandibular symphysis less vertical than in other Baurusuchidae of large size. The greater part of the diagnostic characters of Baurusuchus pachecoi were identified in MCT 1724 - R: high rostrum and compressed lateral, and ziphodont dentition with strong dental reduction, culminating in four premaxillary and five maxillary teeth. In conclusion, as the morphotype cannot be separated morphologically from the type species of the genus and because it has been found in outcrops of the Adamantina Formation, it is possible to identify it as a juvenile Baurusuchus cf. pachecoi. Changes which can be observed gradually from smaller to larger morphotypes, thus being of ontogenetic nature include: an increase in skull ornamentation; the median/posterior portion of the ventral edge of the maxilla passing from straight to concave; and the verticalization of the mandibular symphysis line to close to 45o.

Le Groupe Passa Dois du Permien du bassin du Paraná est révisé et commenté en fonction de l'historique des recherches qui y ont été réalisées. Ce Groupe est classiquement subdivisé en trois Formations: Irati, Estrada Nova et Rio do Rasto. La Formation Corumbatal dont l'existence est discutable est également commentée. Un glossaire de la nomenclature stratigraphique relative aux diverses subdivisions du Groupe complète ce travail. Le Groupe Passa Dois du Permien du bassin du Paraná est révisé et commenté en fonction de l'historique des recherches qui y ont été réalisées. Ce Groupe est classiquement subdivisé en trois Formations: Irati, Estrada Nova et Rio do Rasto. La Formation Corumbatai dont l'existence est discutable est également commentée. Un glossaire de la nomenclature stratigraphique relative aux diverses subdivisions du Groupe complète ce travail.