A New Coelurosaurian Theropod from the La Buitrera Fossil Locality of Río Negro, Argentina

A new coelurosaurian theropod, Alnashetri cerropoliciensis, is reported here based on articulated hind limbs of a single individual discovered at the locality of La Buitrera (Candeleros Formation, Cenomanian–Turonian), Río Negro Province, Argentina. The new taxon differs from other coelurosaurs in the possession of a low ridge that separates the rostral tibial surface from the outer face of the lateral malleolus, and which extends proximally beyond the tip of the ascending process of the astragalus, and in the possession of ventral notches on the hemicondyles of the distal articulations on pedal phalanges III-1 and III-2. Alnashetri is easily distinguished from the dromaeosaurid Buitreraptor, the only other known small theropod from La Buitrera. Phylogenetic analysis supports alvarezsauroid affinities. The evidence supporting this relationship comes from the detailed anatomy of the ankle, however, and this concentration of character support within a single anatomical region may bias our results. If our proposed phylogenetic placement is accurate, Alnashetri antedates all other Argentinian alvarezsaurids and indicates that alvarezsaurids were present in the Neuquén Basin throughout the entire Late Cretaceous.Fil: Makovicky, Peter J.. Field Museum of National History; Estados UnidosFil: Apesteguía, Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; ArgentinaFil: Gianechini, Federico Abel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; Argentin

A new Cretaceous thyreophoran from Patagonia supports a South American lineage of armoured dinosaurs

The early evolution of thyreophoran dinosaurs is thought to have occurred primarily in northern continents since most evidence comes from the Lower and Middle Jurassic of Europe and North America. The diversification into stegosaurs and ankylosaurs is obscured by a patchy fossil record comprising only a handful of fragmentary fossils, most with uncertain phylogenetic affinities. Here we report the discovery of a new armoured dinosaur from the early Late Cretaceous of Argentina, recovered phylogenetically using various datasets either as a basal thyreophoran or a stem ankylosaur, closely related to Scelidosaurus. It bears unusual anatomical features showing that several traits traditionally associated with the heavy Cretaceous thyreophorans did not occur universally. Jakapil kaniukura gen. et sp. nov. is the first definitive thyreophoran species from the Argentinian Patagonia. Unlike most thyreophorans, it seems to show a bipedal stance, as in Scutellosaurus. Jakapil also shows that early thyreophorans had a much broader geographic distribution than previously thought. It is a member of an ancient basal thyreophoran lineage that survived until the Late Cretaceous in South America.The authors thank to Mariluan family for kindly allowing us the access to the fossiliferous locality of Cerro Policia and to the Secretaria de Cultura of the Rio Negro Province for allowing the respective permits; to the Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Agencia Nacional de Promocion de la Investigacion, el Desarrollo Tecnologico y la Innovacion (projects PICT 2014-0564 and PICT 2018-04598), the Fundacion Azara-Universidad Maimonides, the Spanish Ministerio de Ciencia, Innovacion e Universidades and the European Regional Development Fund (projects CGL2017-85038-P and PID2021-122612OB-I00), and the Gobierno Vasco/EJ (research group IT1418-19) for the funding. F. J. R. thanks to I. Diaz-Martinez, A. Martinelli, L. Leahey, R. Molnar, A. Vargas Milne, S. Soto Acuna, and M. Baron for digital material; to L. Pazo and J. Kaluza for the material preparation; to the members of the Area de Paleontologia of the Fundacion Azara, especially F. Garberoglio, L. Fernandez Dumont and J. P. Garderes, for all the helping; to R. Ponti for the thin sectioning, and I. Cerda for his advice on histological aspects; to S. Bogan, S. M. alvarez and J. Meluso for facilitate the access to the Fundacion Azara collections. S. A. acknowledges J. Kaluza for identifying key materials. Thanks to R. Glasgow for reviewing the English text of the manuscript. Special thanks to the reviewers Susannah Maidment, Victoria Arbour, and an anonymous reviewer, whose comments strongly improved the manuscript

An unusual new theropod with a didactyl manus from the upper cretaceous of patagonia, Argentina

Background Late Cretaceous terrestrial strata of the Neuquén Basin, northern Patagonia, Argentina have yielded a rich fauna of dinosaurs and other vertebrates. The diversity of saurischian dinosaurs is particularly high, especially in the late Cenomanian-early Turonian Huincul Formation, which has yielded specimens of rebacchisaurid and titanosaurian sauropods, and abelisaurid and carcharodontosaurid theropods. Continued sampling is adding to the known vertebrate diversity of this unit. Methodology/ Principal Findings A new, partially articulated mid-sized theropod was found in rocks from the Huincul Formation. It exhibits a unique combination of traits that distinguish it from other known theropods justifying erection of a new taxon, Gualicho shinyae gen. et sp. nov. Gualicho possesses a didactyl manus with the third digit reduced to a metacarpal splint reminiscent of tyrannosaurids, but both phylogenetic and multivariate analyses indicate that didactyly is convergent in these groups. Derived characters of the scapula, femur, and fibula supports the new theropod as the sister taxon of the nearly coeval African theropod Deltadromeus and as a neovenatorid carcharodontosaurian. A number of these features are independently present in ceratosaurs, and Gualicho exhibits an unusual mosaic of ceratosaurian and tetanuran synapomorphies distributed throughout the skeleton. Conclusions/ Significance Gualicho shinyae gen. et sp. nov. increases the known theropod diversity of the Huincul Formation and also represents the first likely neovenatorid from this unit. It is the most basal tetatanuran to exhibit common patterns of digit III reduction that evolved independently in a number of other tetanuran lineages. A close relationship with Deltadromaeus from the Kem Kem beds of Niger adds to the already considerable biogeographic similarity between the Huincul Formation and coeval rock units in North Africa.Fil: Apesteguía, Sebastián. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Smith, Nathan D.. Natural History Museum Of Los Angeles County; Estados UnidosFil: Valieri, Rubén Juárez. Provincia de Rio Negro; ArgentinaFil: Makovicky, Peter J.. Field Museum Of Natural History; Estados Unido

Osteohistological analyses reveal diverse strategies of theropod dinosaur body-size evolution

The independent evolution of gigantism among dinosaurs has been a topic of long-standing interest, but it remains unclear if gigantic theropods, the largest bipeds in the fossil record, all achieved massive sizes in the same manner, or through different strategies. We perform multi-element histological analyses on a phylogenetically broad dataset sampled from eight theropod families, with a focus on gigantic tyrannosaurids and carcharodontosaurids, to reconstruct the growth strategies of these lineages and test if particular bones consistently preserve the most complete growth record. We find that in skeletally mature gigantic theropods, weight-bearing bones consistently preserve extensive growth records, whereas non- weight-bearing bones are remodelled and less useful for growth reconstruction, contrary to the pattern observed in smaller theropods and some other dinosaur clades. We find a heterochronic pattern of growth fitting an acceleration model in tyrannosaurids, with allosauroid carcharodontosaurids better fitting a model of hypermorphosis. These divergent growth patterns appear phylogenetically constrained, representing extreme versions of the growth patterns present in smaller coelurosaurs and allosauroids, respectively. This provides the first evidence of a lack of strong mechanistic or physiological constraints on size evolution in the largest bipeds in the fossil record and evidence of one of the longest-living individual dinosaurs ever documented.Fil: Cullen, Thomas. Field Museum of National History; Estados Unidos. North Carolina State University; Estados Unidos. North Carolina Museum of Natural Sciences; Estados UnidosFil: Canale, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Confluencia; Argentina. Provincia del Neuquén. Municipalidad de Villa El Chocón. Museo Paleontológico "Ernesto Bachmann"; ArgentinaFil: Apesteguía, Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Confluencia; Argentina. Fundación de Historia Natural Félix de Azara; Argentina. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; ArgentinaFil: Smith, Nathan D.. Natural History Museum of Los Angeles County. Dinosaur Institute; Estados UnidosFil: Hu, Dongyu. Shenyang Normal University; República de China. Ministry of Natural Resources; República de ChinaFil: Makovicky, Peter J.. Field Museum of National History; Estados Unidos. University of Minnesota; Estados Unido

Efecto del peso de sacrificio sobre la composición de la grasa de corderos de raza lacha

Due to the fact that domestic consumers prefer low fat meat, the lamb production system in Spain is based on slaughtering low weight animals (12 to 24 kg). Lambs in other European countries are slaughtered at higher weights because consumers prefer more intense flavored and fatter meat. Based on evidence that slaughter weight affects fat characteristics, the effect of slaughtering weight on the fatty acid profile of omental (OM), mesenteric (MES), kidney knob (KK), subcutaneous (SC), intermuscular (IN) and intramuscular (IM) fat in Lacha breed lambs was studied. Forty–two male Lacha lambs were raised and slaughtered at 12 (L12), 24 (L24) and 36 kg (L36) live weight. L12 lambs were fed only on mother's milk until slaughter, one month old. L24 and L36 lambs were fed ad libitum on commercial feed and barley straw from weaning (around 16 kg live weight) until slaughter. Adipose tissue samples were taken at the slaughterhouse, vacuum–packed, frozen and stored. Fatty acid methyl esters were analyzed by capillary gas chromatography, and the relative amounts were recorded. The results were analyzed using ANOVA and Tukey's test (p<0.05). Concentrations of C12:0 and C14:0 decreased after weaning due to the fact that the lambs no longer ingested mother's milk. In all fat depots, L24 showed the highest saturated fatty acid concentration, mainly due to the higher C18:0 content. An increase in C18:1n–9cis in heavier lambs (L24 to L36) was observed, associated to fat reserve accumulation processes. The analysis of these data suggests an increase in desaturation enzymes activity among higher–weight lambs, when ruminal activity was initiated. The most suitable n–6/n–3 and polyunsaturated/saturated ratio in muscle fat for preventing cardiovascular disease were observed in L24 lambs.Debido al hecho de que los consumidores domésticos prefieren carne baja en grasas, el sistema de producción de corderos en España se basa en el sacrificio de animales de bajo peso (12 a 24 kg). Los corderos en otros países europeos se sacrifican a pesos mayores porque los consumidores prefieren carne de sabor más intenso y con más grasa. Debido a que el peso del sacrificio afecta las características de grasa, se estudió el efecto del peso de sacrificio de corderos de raza Lacha en el perfil de ácidos grasos de la grasa omental (OM), mesentérica (MES), pelvicorrenal (PVR), subcutánea (SC), intermuscular (IN) e intramuscular (IM). Cuarenta y dos corderos machos de raza Lacha se criaron y sacrificaron con un peso vivo de 12 (L12), 24 (L24) y 36 (L36) kg. Los L12 se alimentaron únicamente con leche materna hasta su sacrificio, a un mes de nacidos. Los corderos L24 y L36 se alimentaron ad libitum con alimento comercial y paja de cebada desde el destete (alrededor de 16 kg de peso vivo) hasta el sacrificio. En la planta de sacrificio (matadero) se tomaron muestras de tejido adiposo; se empacaron al vacío, se congelaron y se almacenaron. Se analizó los ésteres metílicos de los ácidos grasos por cromatografía de gases capilar y se registraron las cantidades relativas. Los resultados se analizaron usando ANDEVA y la prueba de Tukey (p<0.05). Las concentraciones de C12:0 y C14:0 disminuyeron después del destete debido a que los corderos ya no consumían la leche de la madre. En todos los depósitos de grasa, L24 mostró la concentración más alta de ácidos grasos saturados, principalmente debido al mayor contenido de C18:0. Se observó un aumento en C18:1n–9cis en corderos más pesados (L24 a L36), asociado a los procesos de acumulación de reservas de grasa. El análisis de estos datos sugiere un aumento en la actividad de enzimas de desaturación en los corderos de mayor peso, una vez iniciada la actividad ruminal. La tasa más adecuada de n–6/n–3 y poliinsaturado/saturado en grasa muscular para prevenir la enfermedad cardiovascular se observó en corderos L24

Effect of Sex and Fat Depot Location on Fat Composition of Rasa Aragonesa Lambs

The quality of lamb fat is important in sheep carcass markets because it affects the degree of acceptance by consumers. In Spain, consumption of beef and lamb is important and young lambs are highly valued. In addition, the precocity of the female determines slaughter at younger ages than males, to avoid excessive fat. Therefore, the effect of sex and fat depot location (omental, mesenteric, kidney knob, subcutaneous, intermuscular and intramuscular) on the fatty acid composition in 30 Rasa Aragonesa lambs (15 males and 15 females) of 24 kg live weight and three months of age, were studied. Oleic, palmitic and stearic fatty acids were the main fatty acids making up the fat in all the fat depots from lambs. There were no significant differences (p0.05) in the fat composition between male and female lambs, even though females had significantly more fat than males in all the fat depots considered (p0.05). Criteria associated with sex did not affect the composition of fat. Ratio of fatty acids n-6/n-3 values were in the range of recommended average values (4), except for intramuscular fat, where values marginally higher were observed (5.5). The internal (omental, mesenteric and kidney knob) fat depots contained more saturated fatty acids than the edibles depots (subcutaneous, intermuscular and intramuscular) (p0.05). Consequently, the internal fat depot was firmer than fat from the surface of the carcass. Fatty acid of intramuscular fat depot had the highest content of PUFA of all fat deposits studied.La calidad de la grasa de cordero es importante en los mercados de canales ovinas porque afecta al grado de aceptación de los consumidores. En España, el consumo de carne de res y cordero es importante, y los corderos jóvenes son muy valorados. Además, la precocidad de las hembras determina su sacrificio a edades más tempranas que los machos para evitar su excesivo engrasamiento. Por tanto, se estudiaron el efecto del sexo y del depósito de grasa (omental, mesentérica, pelvicorrenal, subcutánea, intermuscular e intramuscular) sobre la composición de ácidos grasos en 30 corderos de raza Rasa Aragonesa (15 machos y 15 hembras) de 24 kg de peso vivo y tres meses de edad. Los principales ácidos grasos que componen la grasa en todos los depósitos de grasa de los corderos fueron los ácidos oleico, palmítico y esteárico. No hubo diferencias significativas (p0.05) en la composición de la grasa entre los corderos machos y hembras, a pesar de que las hembras presentaron significativamente más grasa que los machos en todos los depósitos considerados (p0.05). Los criterios asociados con el sexo no afectaron a la composición de la grasa. La relación de ácidos grasos n-6/n-3 se encontró en el rango de los valores promedio recomendados (4), excepto la grasa intramuscular, donde se observaron valores más altos (5.5). Los depósitos de grasa interna (omental, mesentérica y pelvicorrenal) mostraron más ácidos grasos saturados que los depósitos comestibles (subcutáneo, intermuscular e intramuscular) (p0.05). En consecuencia, el depósito de grasa interna presentó grasa más firme que el de la superficie de la canal. Los ácidos grasos del depósito intramuscular presentó el contenido más alto de ácidos grasos poliinsaturados de todos los depósitos de grasa estudiados

Application of MIR spectroscopy to the evaluation of chemical composition and quality parameters of foal meat: a preliminary study

The aim of this work was to study the potential of mid-infrared spectroscopy to evaluate the chemical composition and quality parameters of foal meat according to differences based on slaughter ages and finishing diets. In addition, the wavelength ranges which contribute to this meat quality differentiation were also determined. Important characteristics as moisture and total lipid content were well predicted using Mid-Infrared Spectroscopy (MIR) with Rv2 values of 82% and 66%, respectively. Regarding fatty acids, the best models were obtained for arachidonic, vaccenic, docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) with Rv2 values over 65%. Quality parameters, as instrumental colour and texture and sensory attributes did not reach high prediction coefficients (R2). With the spectra data of the region 2198–1118 cm-1, samples were accurately classified according to slaughter age (78%) and finishing diet (72%). This preliminary research shows the potential of MIR spectroscopy as an alternative tool to traditional meat chemical composition methods. Finally, the wavelength range of the spectrum from 2198 to 1118 cm-1 showed good results for classification purposes.This research was funded by INIA Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, grant number RTA 2012-00090-C03-01 and by the Spanish Ministerio de Ciencia, Innovación y Universidades, Project RTI2018-094475-B-I00 (MCIU/AEI/FEDER, UE)

A new rhynchocephalian from the late jurassic of Germany with a dentition that is unique amongst tetrapods.

Rhynchocephalians, the sister group of squamates (lizards and snakes), are only represented by the single genus Sphenodon today. This taxon is often considered to represent a very conservative lineage. However, rhynchocephalians were common during the late Triassic to latest Jurassic periods, but rapidly declined afterwards, which is generally attributed to their supposedly adaptive inferiority to squamates and/or Mesozoic mammals, which radiated at that time. New finds of Mesozoic rhynchocephalians can thus provide important new information on the evolutionary history of the group. A new fossil relative of Sphenodon from the latest Jurassic of southern Germany, Oenosaurus muehlheimensis gen. et sp. nov., presents a dentition that is unique amongst tetrapods. The dentition of this taxon consists of massive, continuously growing tooth plates, probably indicating a crushing dentition, thus representing a previously unknown trophic adaptation in rhynchocephalians. The evolution of the extraordinary dentition of Oenosaurus from the already highly specialized Zahnanlage generally present in derived rhynchocephalians demonstrates an unexpected evolutionary plasticity of these animals. Together with other lines of evidence, this seriously casts doubts on the assumption that rhynchocephalians are a conservative and adaptively inferior lineage. Furthermore, the new taxon underlines the high morphological and ecological diversity of rhynchocephalians in the latest Jurassic of Europe, just before the decline of this lineage on this continent. Thus, selection pressure by radiating squamates or Mesozoic mammals alone might not be sufficient to explain the demise of the clade in the Late Mesozoic, and climate change in the course of the fragmentation of the supercontinent of Pangaea might have played a major role

Mesoscopic structure conditions the emergence of cooperation on social networks

We study the evolutionary Prisoner's Dilemma on two social networks obtained from actual relational data. We find very different cooperation levels on each of them that can not be easily understood in terms of global statistical properties of both networks. We claim that the result can be understood at the mesoscopic scale, by studying the community structure of the networks. We explain the dependence of the cooperation level on the temptation parameter in terms of the internal structure of the communities and their interconnections. We then test our results on community-structured, specifically designed artificial networks, finding perfect agreement with the observations in the real networks. Our results support the conclusion that studies of evolutionary games on model networks and their interpretation in terms of global properties may not be sufficient to study specific, real social systems. In addition, the community perspective may be helpful to interpret the origin and behavior of existing networks as well as to design structures that show resilient cooperative behavior.Comment: Largely improved version, includes an artificial network model that fully confirms the explanation of the results in terms of inter- and intra-community structur