The last dinosaurs of Brazil: The Bauru Group and its implications for the end-Cretaceous mass extinction

ABSTRACT The non-avian dinosaurs died out at the end of the Cretaceous, ~66 million years ago, after an asteroid impact. The prevailing hypothesis is that the effects of the impact suddenly killed the dinosaurs, but the poor fossil record of latest Cretaceous (Campanian-Maastrichtian) dinosaurs from outside Laurasia (and even more particularly, North America) makes it difficult to test specific extinction scenarios. Over the past few decades, a wealth of new discoveries from the Bauru Group of Brazil has revealed a unique window into the evolution of terminal Cretaceous dinosaurs from the southern continents. We review this record and demonstrate that there was a diversity of dinosaurs, of varying body sizes, diets, and ecological roles, that survived to the very end of the Cretaceous (Maastrichtian: 72-66 million years ago) in Brazil, including a core fauna of titanosaurian sauropods and abelisaurid and carcharodontosaurid theropods, along with a variety of small-to-mid-sized theropods. We argue that this pattern best fits the hypothesis that southern dinosaurs, like their northern counterparts, were still diversifying and occupying prominent roles in their ecosystems before the asteroid suddenly caused their extinction. However, this hypothesis remains to be tested with more refined paleontological and geochronological data, and we give suggestions for future work.

Early Devonian (Late Emsian) shark fin remains (Chondrichthyes) from the Paraná Basin, southern Brazil

ABSTRACT We report on the pioneering discovery of Devonian fish remains in the Paraná Basin, which represents the southernmost record of fishes from that period in mainland South America. The material comes from an outcrop at the lower portion of the São Domingos Formation, within Sequence C of the Paraná-Apucarana sub-basin in Tibagi, State of Paraná. Marine invertebrates are abundant in the same strata. The dark colored fish remains were collected in situ and represent natural moulds of partially articulated shark fin rays (radials). No elements such as teeth or prismatic cartilage have been preserved with the fins rays. This can be attributed to the dissolution of calcium-phosphatic minerals at the early stages of fossilization due to diagenetic processes possibly linked to strong negative taphonomic bias. This may have contributed to the fact that fishes remained elusive in the Devonian strata of this basin, despite substantial geological work done in the Paraná State in recent decades. In addition, the scarcity of fish fossils may be explained by the fact that the Devonian rock deposits in this basin originated in a vertebrate impoverished, cold marine environment of the Malvinokaffric Realm, as previously suspected.

Revisão do Ramo Gondwânico da família Mawsoniidae (Sarcopterygii: Actinistia: Coelacanthiformes) / Review of Gondwana Branch of the Mawsoniidae family (Sarcopterygii: Actinistia: Coelacanthiformes)

Representados aualmente por apenas duas espécies: Latimeria chalumnae e L. menadoensis, os celacantos (Infraordem Actinistia) já foi muito mais numeroso, prolífico desde os tempos de seu surgimento no Devoniano Inferior. Dentro de Actinistia a família Mawsoniidae se destaca por abranger as maiores espécies do grupo, algumas atingindo até três metros de comprimento. A entrada de Mawsoniidae no continente Gondwana se deu durante o Jurássico superior, período o qual é atribuído a espécie Parnaibaia maranhoensis da bacia do Parnaíba (Maranhão). No cretáceo a família se ramificou em dois outros gêneros Mawsonia (com conhecidas ocorrências brasileiras e africanas) e Axelrodichthys (gênero brasileiro com alguns indícios de presença na África). Este trabalho teve por objetivo realizar uma redescrição e comparação de seis espécies do ramo gondwânico da família Mawsoniidae: Parnaibaia maranhoensis, Axelrodichthys araripensis, Mawsonia gigas, M. minor, M. lavocati e M. brasiliensis. Os espécimes estão depositados em oito instituições: três nacionais e cinco internacionais. Após uma criteriosa descrição anatômica dos exemplares caracteres foram selecionados para a realização de uma análise filogenética restrita ao grupo. Os resultados das observações anatômicas revelaram diversas estruturas ainda não descritas na literatura, incluindo o primeiro elemento medial do esqueleto apendicular de Mawsoniidae a ser observado, além de diversas diferenças e afinidades entre as seis espécies. P. maranhoensis apresentou um conjunto de caracteres plesiomórfico que foram interpretados como sendo o resultado de um evento de neotenia, algo inédito na literatura de celacantos. Todas as espécies do gênero Mawsonia apresentaram características diagnósticas que validam sua separação em espécies distintas. A análise filogenética resultou em duas árvores igualmente parcimoniosas...

Represented at the present with only two species: Latimeria chalumnae and Latimeria medadoensis, the coelacanth (Infraorder: Actinistia) were once a very numerous and prolific group since their dawn in the Lower Devonian. Amongst the Actinistia, the family Mawsoniidae stands out for harboring the biggest species in the group, some reaching three meters in length. The entry of the Mawsoniidae family on the Gondwana continent happened during Upper Jurassic, period attributed to the species Parnaibaia maranhoensis from the Parnaíba basin (Maranhão). During the Cretaceous, the family branched into two distinct genus: Mawsonia (known from Brazil and Africa) and Axelrodichthys (a Brazilian genus with unconfirmed African occurrences). The goal of this work was to make a redescription and comparison of six species of the Gondwana branch of the Mawsoniidae family: Parnaibaia maranhoensis, Axelrodichthys araripensis, Mawsonia gigas, M. minor, M. lavocati e M. brasiliensis. The specimens are located in eight institutions: three nationals and five internationals. After a thorough anatomical description of the specimens, characters were selected for a phylogenetic analysis, restricted to the group. The results of the anatomical observations revealed several structures not described in previous literature, including the first medial element of the appendicular skeleton of the Mawsoniidae family ever to be observed, aside from differences and affinities between the six species. P. maranhoensis presented a set of plesiomorfic characters that were interpreted as being the result of a neotenic event, something not yet described in the specialized literature. Every species of the genus Mawsonia showed diagnostic characters that validate their respective status as a distinctive species...

Plate motions, Gondwana Dinosaurs, Noah's Arks, Beached Viking Funeral Ships, Ghost Ships, and Landspans

Gondwana landmasses have served as large-scale biogeographic Noah's Arks and Beached Viking Funeral Ships, as defined by McKenna. The latitudinal trajectories of selected Gondwana dinosaur localities were traced through time in order to evaluate their movement through climate zones relative to those in which they originally formed. The dispersal of fauna during the breakup of Gondwana may have been facilitated by the presence of offshelf islands forming landspans (sensu Iturralde-Vinent and MacPhee) in the Equatorial Atlantic Gateway and elsewhere.

As massas de terra do Gondwana serviram como Arcas de Noe biogeograficas de grande escala e Navios Funerarios Vikings encalhados, conforme definido por McKenna. As trajetorias latitudinais de areas selecionadas de dinossauros do Gondwana foram tracadas ao longo do tempo a fim de avaliar seu movimento atraves de zonas climaticas relativas aquelas nas quais elas foram originalmente formadas. A dispersao da fauna durante a quebra do Gondwana pode ter sido facilitada pela presenca de ilhas oceanicas formando extensoes de terra (sensu Iturralde-Vinent e MacPhee) na entrada do Atlantico Equatorial e em outros lugares.

Unenlagiid theropods: are they members of the Dromaeosauridae (Theropoda, Maniraptora)?

In the present paper we analyze the phylogenetic position of the derived Gondwanan theropod clade Unenlagiidae. Although this group has been frequently considered as deeply nested within Deinonychosauria and Dromaeosauridae, most of the features supporting this interpretation are conflictive, at least. Modification of integrative databases, such as that recently published by Hu et al. (2009), produces significant changes in the topological distribution of taxa within Deinonychosauria, depicting unenlagiids outside this clade. Our analysis retrieves, in contrast, a monophyletic Avialae formed by Unenlagiidae plus Aves.

No presente trabalho analisou-se a posição filogenética do clado derivado de terópodas gondwânicos Unenlagiidae. Embora este grupo tenha sido frequentemente considerado como profundamente enraizado entre Deinonychosauria e Dromaeosauridae, grande parte das características que sustentam esta interpretação e no minimo conflitiva. A modificação de bancos de dados integrativos, tal como a recentemente publicada por Hu et al. (2009), produz mudanças significativas na distribuifao topologica dos táxons dentro de Deinonychosauria, representando unenlagiids fora deste clado. Nossa analise recupera, em contrapartida, um Avialae monofilético formado por Unenlagiidae e Aves.

Record of the genus Lycopodites in the Lower Permian of Paraná Basin, Brazil

The genus Lycopodites, which encompasses the herbaceous forms of the lycopsids, presents broad time and spacial distribution during the Paleozoic in the Northern Hemisphere, with its initial records dating from the European Devonian. As to Gondwanan Paleozoic, to this moment, only Lycopodites amazonica Dolianiti had been reported for the Amazonian Middle Devonian (Curuá Group). Thus, the specimens reported in this study such as Lycopodites sp., coming from sedimentary rocks of the Itararé Subgroup, São Paulo State, and Lycopodites riograndensis sp. nov., collected in Rio Bonito Formation, Rio Grande do Sul, represent the oldest fertile forms recorded for Gondwana and the first ones to be described for the Paraná Basin. Its presence in layers, deposited after the end of the Neopaleozoic Glaciation, shows the appearance of new taxa in high latitudes, as well as the diversity of the lycopsids present in the Basin, previously indicated through the abundance of spores associated to the Class Lycopsida present in the palinomorphous assemblages.

O gênero Lycopodites, que engloba formas herbáceas de licópsidas, apresenta ampla distribuição temporal e espacial durante o Paleozóico no Hemisfério Norte, iniciando seu registro no Devoniano da Europa. Já no Paleozóico do Gondwana, até o presente momento, somente Lycopodites amazonica Dolianiti havia sido reportada para o Devoniano Médio da Amazônia (Grupo Curuá). Assim, os exemplares reportados no presente trabalho como Lycopodites sp., provenientes de rochas sedimentares do Subgrupo Itararé, SP, e Lycopodites riograndensis sp. nov., coletados na Formação Rio Bonito, RS, representam as formas férteis mais antigas registradas para o Gondwana e as primeiras a serem descritas para a Bacia do Paraná. A sua presença em camadas depositadas após o término da glaciação neopaleozóica, evidencia o ingresso de novos taxa em latitudes altas, bem como a diversidade das licópsidas presentes na Bacia, já esboçada através dos abundantes esporos associados à Classe Lycopsida presentes nas assembléias de palinomorfos.

A new Cretaceous terrestrial ecosystem from Gondwana with the description of a new sauropod dinosaur

A unique site at the northern area of Patagonia (Neuquén, Argentina) reveals a terrestrial ecosystem preserved in a detail never reported before in a Late Cretaceous deposit. An extraordinary diversity and abundance of fossils was found concentrated in a 0.5 m horizon in the same quarry, including a new titanosaur sauropod, Futalognkosaurus dukei n.gen., n.sp, which is the most complete giant dinosaur known so far. Several plant leaves, showing a predominance of angiosperms over gymnosperms that likely constituted the diet of F. dukei were found too. Other dinosaurs (sauropods, theropods, ornithopods), crocodylomorphs, pterosaurs, and fishes were also discovered, allowing a partial reconstruction of this Gondwanan continental ecosystem.

Um depósito fóssil na região norte da Patagônia (Neuquén, Argentina) revela um ecossistema nunca antes registrado a este nível de detalhes em depósitos do Cretáceo Superior. Uma diversidade e abundância extraordinária de fósseis encontra-se concentrada em uma camada de 0,5 m no mesmo sítio, incluindo um novo saurópodo titanossaurídeo, Futalognkosaurus dukei n. gen, n. sp., que é o mais completo dinossauro gigante encontrado até a presente data. Foram descobertas váriasfolhas de plantas indicando a predominância de angiospermas sobre gimnospermas que possivelmente formavam a base da dieta de F. dukei. Outros dinossauros (saurópodes, terópodes, ornitópodes), crocodilomorfos, pterossauros e peixes foram também encontrados possibilitando a reconstrução parcialdeste ecossistema continental do Gondwana.

Biogeographic analysis of Crocidiinae (Diptera, Bombyliidae): finding congruence among morphological, molecular, fossil and paleogeographical data

Biogeographic studies dealing with Bombyliidae are rare in the literature and no information is available on its origin and early diversification. In this study, we found evidence from molecular phylogeny and from fossil record supporting a Middle Jurassic origin of the Bombylioidea, taken as a starting point to discuss the biogeography and diversification of Crocidiinae. Based on a previously published phylogenetic hypothesis, we performed a Brooks Parsimony Analysis (BPA) to discuss the biogeographical history of Crocidiinae lineages. This subfamily is mostly distributed over arid areas of the early components of the Gondwanaland: Chile and southern Africa, but also in southwestern Palaearctic and southwestern Nearctic. The vicariant events affecting the Crocidiinae biogeography at the generic level seems to be related to the sequential separation of a Laurasian clade from a Gondwanan clade followed by the splitting of the latter into smaller components. This also leads to a hypothesis of origin of the Crocidiinae in the Middle Jurassic, the same period in which other bombyliid lineages are supposed to have arisen and irradiated.

Estudos biogeográficos sobre os Bombyliidae são raros na literatura e não há nenhuma informação sobre sua origem e diversificação inicial. Neste estudo encontramos evidências de filogenias moleculares e de registros fósseis suportando a origem dos Bombylioidea no Jurássico Médio. Esse é o nosso ponto de partida para discutir a biogeografia e diversificação de Crocidiinae. A partir de uma hipótese filogenética previamente publicada, realizamos uma Análise de Parcimônia de Brooks (BPA) para discutir a história biogeográfica das linhagens de Crocidiinae. Esta subfamília está distribuída principalmente por áreas áridas dos antigos componentes do supercontinente gondwanico: Chile e Sul da África, além do sudoeste da região Paleártica e sudoeste da região Neártica. Os eventos vicariantes que afetaram a biogeografia de Crocidiinae ao nível genérico parecem ser a separação seqüencial de um clado laurásico e um clado gondwanico, seguido da divisão deste em seus componentes menores. Com base nesses eventos, a origem dos Crocidiinae pode ser inferida para o Jurássico Médio, mesmo período em que outras linhagens de Bombyliidae teriam surgido e irradiado.

Breves Notícias Sobre a Geologia dos Estados do Paraná e Santa Catarina

The present short survey of the geology of the States of Paraná and Santa Catarina was written as a text to accompany sketches for the revision of the GEOLOGICAL MAP OF SOUTH AMERICA. It contains the results of geologic research up to the year 1947 in most concise form, without going into detail. As requested, the occurrence of useful minerals was not considered in the summary, and the list of bibliographical references has been condensed to the uttermost. Inasmuch as the author treated the Passa Dois Series in more detail, due to the reorganization of the Gondwana beds, the Archean and the Algonkian had to be reduced to the minimum. This was possible, since the innumerable details of the phenomena in the crystalline complex could not be represented in a geologic map of the given scale. The reorganization of the geologic constituents of Paraná and Santa Catarina is summarized in Stratigraphic Table nº 2, and is explained by the enclosed sketches.

Die vorliegende kurze Übersicht zur Geologie der Staaten Paraná und Santa Catarina wurde als Begleittext zur Skizze für die Revision der GEOLOGICAL MAP OF SOUTH AMERICA verfasst. Sie enthält die Ergebnisse der geologischen Forschung bis zum Jahre 1947 in gedrängtester Form, wobei auf Einzelheiten nicht eingegangen wird. Auf ausdrücklichen Wunsch sind die Vorkommen nutzbarer Mineralien in der Übersicht nicht berücksichtigt, und auch das Literatur-Verzeichnis auf das Äusserste eingeschränkt worden. Da der Verfasser im Hinblick auf die Neugliederung der Gondwana-Schichten die Serie Passa Dois etwas eingehender behandelte, mussten dafür Archaeikum und Algonkium auf das Mindestmass gekürzt werden. Das war dadurch möglich, dass bei den mannigfachen Einzelheiten der Erscheinungen im kristallinen Komplex diese bei dem für die geologische Karte vorgesehenen Masstab doch nicht dargestellt werden konnten. Die Neugliederung der geologischen Baustoffe von Paraná und Santa Catarina ist in der stratigrafischen Tabelle nº 2 zusammengefasst und wird durch die beigefügten Skizzen erläutert.