Recovering missing data: estimating position and size of caudal vertebrae in Staurikosaurus pricei Colbert, 1970

Missing data is a common problem in paleontology. It makes it difficult to reconstruct extinct taxa accurately and restrains the inclusion of some taxa on comparative and biomechanical studies. Particularly, estimating the position of vertebrae on incomplete series is often non-empirical and does not allow precise estimation of missing parts. In this work we present a method for calculating the position of preserved middle sequences of caudal vertebrae in the saurischian dinosaur Staurikosaurus pricei, based on the length and height of preserved anterior and posterior caudal vertebral centra. Regression equations were used to estimate these dimensions for middle vertebrae and, consequently, to assess the position of the preserved middle sequences. It also allowed estimating these dimensions for non-preserved vertebrae. Results indicate that the preserved caudal vertebrae of Staurikosaurus may correspond to positions 1-3, 5, 7, 14-19/15-20, 24-25/25-26, and 29-47, and that at least 25 vertebrae had transverse processes. Total length of the tail was estimated in 134 cm and total body length was 220-225 cm.<br>Dados lacunares são um problema comum na paleontologia. Eles dificultam a reconstrução acurada de táxons extintos e limitam a inclusão de alguns táxons em estudos comparativose biomecânicos. Particularmente, estimar a posição de vértebras em séries incompletas tem sido feito com base em métodos não empíricos que não permitem estimar corretamente as partes ausentes. Neste trabalho apresentamos uma metodologia que permite estimar a posição de sequências médias preservadas de vértebras caudais no dinossauro saurísquio Staurikosaurus pricei, com base no comprimento e altura dos centros das vértebras anteriores e posteriores preservadas. Equações de regressão foram usadas para estimar essas dimensões para as vértebras médias e, consequentemente, para posicionar as sequências médias preservadas e para estimar o tamanho das vértebras não preservadas. Os resultados indicam que as vértebras caudais preservadas de Staurikosaurus corresponderiam às posições 1-3, 5, 7, 14-19/15-20, 24-25/25-26 e 29-47, e que pelo menos 25 vértebras possuíam processos transversos. O comprimento total da cauda foi estimado em 134 cm e o comprimento total do corpo em 220-225 cm

A new dinosaur (Theropoda, Spinosauridae) from the Cretaceous (Cenomanian) Alcântara Formation, Cajual Island, Brazil

A new spinosaurid taxon, Oxalaia quilombensis gen. et sp. nov., is described based on the anterior part of a snout and a fragment of a maxilla. These specimens were collected at the Laje do Coringa site, Late Cretaceous (Cenomanian) of the São Luis Basin. Unlike Cristatusaurus and Suchomimus, Oxalaia quilombensis lacks serrations on the teeth. The new species differs from Angaturama limai by having the anterior part of the premaxillae more expanded and by lacking a sagittal premaxillary crest. It further differs from Spinosaurus cf. S. aegyptiacus and the Algerian spinosaurid by the rounder shape of the terminal expansion. Furthermore, xalaia quilobensis has one functional tooth followed by two replacement teeth, a feature not previously observed in theropods. Oxalaia quilombensis appears to be more closely related to the spinosaurids found in North Africa than to the Brazilian members of this clade and thus further increases the diversity of these enigmatic predatory dinosaurs in this country

On a new peirosaurid crocodyliform from the Upper Cretaceous, Bauru Group, southeastern Brazil

A new crocodyliform from the Upper Cretaceous (Campanian-Maastrichtian) Presidente Prudente Formation of the Bauru Group is described based on two almost complete skulls and mandibles. The material comes from the "Tartaruguito" site, situated at an old railroad between the cities of Pirapozinho and Presidente Prudente, state of São Paulo, Brazil. The new species, Pepesuchus deiseae gen. et sp. nov., is classified in the clade Peirosauridae on the basis of three synapomorphies: the presence of five premaxillary teeth, the anterior two premaxillary alveoli nearly confluent, and the oval cross-section of the jugal along the lower temporal bar. The new taxon increases the outstanding crocodyliform diversity of the Bauru Group, particularly of the Peirosauridae, which might turn out to be one of the most representative clades of gondwanan mesoeucrocodylians.<br>Um novo crocodilomorfo da Formação Presidente Prudente, Cretáceo Superior (Campaniano-Maastrichtiano) do Grupo Bauru é descrito com base em dois exemplares, consistindo de crânio e mandíbulas quase completos. O material é procedente da localidade conhecida como "Tartaruguito", situada em um antigo ramal ferroviário que ligava as cidades de Pirapozinho e Presidente Prudente, Estado de São Paulo, Brasil. A nova espécie, denominada de Pepesuchus deiseae gen. et sp. nov., é classificada no clado Peirosauridae, com base em três sinapomorfias: presença de cinco dentes pré-maxilares, os dois primeiros alvéolos da pré-maxila quase confluentes e a secção transversal do jugal ao longo da barra temporal inferior oval. O novo táxon aumenta a marcante diversidade de crocodiliformes do Grupo Bauru e dos Peirosauridae, que poderá vir a ser um dos clados mais representativos de mesoeucrocodilianos gondwânicos

Pelvic and hind limb musculature of Staurikosaurus pricei (Dinosauria: Saurischia)

The study of pelvic and hind limb bones and muscles in basal dinosaurs is important for understanding the early evolution of bipedal locomotion in the group. The use of data from both extant and extinct taxa placed into a phylogenetic context allowed to make well-supported inferences concerning most of the hind limb musculature of the basal saurischian Staurikosaurus pricei Colbert, 1970 (Santa Maria Formation, Late Triassic of Rio Grande do Sul, Brazil). Two large concavities in the lateral surface of the ilium represent the origin of the muscles iliotrochantericus caudalis plus iliofemoralis externus (in the anterior concavity) and iliofibularis (in the posterior concavity). Muscle ambiens has only one head and originates from the pubic tubercle. The origin of puboischiofemoralis internus 1 possibly corresponds to a fossa in the ventral margin of the pré-acetabular iliac process. This could represent an intermediate stage prior to the origin of a true pré-acetabular fossa. Muscles caudofemorales longus et brevis were likely well developed, and Staurikosaurus is unique in bearing a posteriorly projected surface for the origin of caudofemoralis brevis.<br>O estudo da musculatura pelvica e do membro posterior em dinossauros basais e importante para entender a evolução inicial do bipedalismo em dinossauros Saurischia. Empregando uma metodologia que tem como base dados obtidos a partir de taxons viventes e extintos posicionados em um contexto filogenetico, foi possivel fazer inferencias bem suportadas relativas a maior parte dos musculos do membro posterior do dinossauro Saurischia basal Staurikosaurus pricei Colbert, 1970 (Formação Santa Maria, Triassico Superior do Rio Grande do Sul, Brasil). Duas grandes concavidades na superficie lateral do ilio correspondem a origem dos musculos iliotrochantericus caudalis e iliofeoralis externus (compartilhando a concavidade anterior) e para o musculo iliofibularis (na concavidade posterior). O musculo ambiens apresenta apenas um ramo que se origina no tuberculo pubico. A origem provavel do musculo puboischiofemoralis internus 1 esta localizada numa fossa na margem ventral do processo pré-acetabular do ilio, representando um estagio anterior a formacão da verdadeira fossa pré-acetabular. Os musculos caudofemorales longus et brevis sao bem desenvolvidos e Staurikosaurus e unico por apresentar a superficie de origem do musculo caudofeoralis brevis projetada e expandida posteriormente

Mechanical ventilation in patients with cardiogenic pulmonary edema : a sub-analysis of the LUNG SAFE study

Patients with acute respiratory failure caused by cardiogenic pulmonary edema (CPE) may require mechanical ventilation that can cause further lung damage. Our aim was to determine the impact of ventilatory settings on CPE mortality. Patients from the LUNG SAFE cohort, a multicenter prospective cohort study of patients undergoing mechanical ventilation, were studied. Relationships between ventilatory parameters and outcomes (ICU discharge/hospital mortality) were assessed using latent mixture analysis and a marginal structural model. From 4499 patients, 391 meeting CPE criteria (median age 70 [interquartile range 59-78], 40% female) were included. ICU and hospital mortality were 34% and 40%, respectively. ICU survivors were younger (67 [57-77] vs 74 [64-80] years, p < 0.001) and had lower driving (12 [8-16] vs 15 [11-17] cmHO, p < 0.001), plateau (20 [15-23] vs 22 [19-26] cmHO, p < 0.001) and peak (21 [17-27] vs 26 [20-32] cmHO, p < 0.001) pressures. Latent mixture analysis of patients receiving invasive mechanical ventilation on ICU day 1 revealed a subgroup ventilated with high pressures with lower probability of being discharged alive from the ICU (hazard ratio [HR] 0.79 [95% confidence interval 0.60-1.05], p = 0.103) and increased hospital mortality (HR 1.65 [1.16-2.36], p = 0.005). In a marginal structural model, driving pressures in the first week (HR 1.12 [1.06-1.18], p < 0.001) and tidal volume after day 7 (HR 0.69 [0.52-0.93], p = 0.015) were related to survival. Higher airway pressures in invasively ventilated patients with CPE are related to mortality. These patients may be exposed to an increased risk of ventilator-induced lung injury. Trial registration Clinicaltrials.gov NCT02010073

Underlying Event measurements in pp collisions at s=0.9 \sqrt {s} = 0.9 and 7 TeV with the ALICE experiment at the LHC

We present measurements of Underlying Event observables in pp collisions at s√=0.9 and 7TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p T,LT in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p T thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2–3 between the lower and higher collision energies, depending on the track p T threshold considered. Data are compared to Pythia 6.4, Pythia 8.1 and Phojet. On average, all models considered underestimate the multiplicity and summed p T in the Transverse region by about 10–30%