The family Gallieniellidae (araneae, gnaphosoidea) in the americas

Azilia leucostigma Mello-Leitao 1941 considered by Mello-Leitao as a metine (Tetragnathidae), is transferred to the gnaphosoid family Gallieniellidae, as the type species of the new genus Galianoella. The obliquely depressed endites, the flattened irregular postenor median eyes, and the conical anterior lateral spinnerets retaining a sclerotized distal ring, among other characters, clearly place the new genus in the family Gallieniellidae. Galianoella leucostigma is the only gallieniellid so far recorded fom the Americas. This species has a specialized ant-preying behavior. Ant-preying may prove to be characteristic for all the family, as it was suspected in the Madagascan Gallieniella; and it may be associated with the modified chelicerae typical of the family.Fil: Goloboff, Pablo Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentin

Association between neotropical burrowing spiders (araneae: nemesiidae) and mites (acari: heterostigmata, scutacaridae)

Whilst collecting burrowing spiders of the family Nemesiidae from 16 localities in Argentina, phoretic mites were found on Stenoterommata iguazu, Stenoterommata platense and Stenoterommata uruguai. These mites are described here: Scutacarus (S.) araneophilus n. sp. and Scutacarus (S.) adgregatus n. sp. Assocations between spiders and scutacarids were not previouly known. Aspects of the biology of the spiders and the interactions between mites and spiders are reported and discussed.Durante colectas de arafias cavadoras de la familia Nemesiidae en I 6 localidades de Argentina, se encontraron acaros foreticos sobre Stenoterommata iguazu, S. platense, and S. uruguai. Se describe aqui a estos acaros, como Scutacarus ( S.) araneophilus n. sp. and Scutacarus ( S.) adgregatus n.sp. Ninguna asociaci6n entre arafias y escutacaridos se conocia previamente. Se discute la interacci6n entre Ios acaros y las arafias, tomando en cuenta Ios datos conocidos de la biologia de ambos.Fil: Ebermann, Ernst. Karl Franzens University; AustriaFil: Goloboff, Pablo Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto Superior de Entomología; Argentin

The Impact of Unstable Taxa in Coelurosaurian Phylogeny and Resampling Support Measures for Parsimony Analyses

Paleontological datasets often have large amounts of missing entries that result in multiple mostparsimonious trees. Highly incomplete and conflictive taxa produce a collapsed strict consensus andseveral methods have been developed for identifying these unstable or rogue taxa in optimal treesderived from phylogenetic analyses. In addition to decreasing consensus resolution, incomplete orconflictive taxa can also severely affect the support values of phylogenetic analysis in paleontologicaldatasets. Here, we explore a protocol for the identification of taxa that decrease jackknife supportvalues in parsimony analysis. The taxa identified are excluded from majority rule jackknife trees,revealing nodes that have either low or high support irrespective of the uncertainties in the placement of unstable taxa. A recently published dataset of coelurosaurian relationships based on 164taxa and 853 characters is explored using this protocol; our protocol detects a total of 40 unstabletaxa as the most detrimental for node supports. Major clades that are well supported in the reducedjackknife tree include Coelurosauria, Maniraptoriformes, Compsognathidae, Ornithomimosauria,Alvarezsauroidea, Therizinosauria, Oviraptorosauria. Clades with moderate support instead includeManiraptora, Pennaraptora, Paraves, Dromaeosauridae, Troodontidae, Anchiornithinae, and earlydiverging clades of Avialae.Fil: Pol, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Museo Paleontológico Egidio Feruglio; ArgentinaFil: Goloboff, Pablo Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentin

A phylogeny of the tinamous (Aves: Palaeognathiformes) based on integumentary characters

A cladistic analysis of the tinamous, including the 47 currently recognized species and some distinct subspecies, was conducted based on 80 integumentary characters from adult and natal plumage, ramphoteca (corneum sheath of bill), and podoteca (horny scales of legs). For the adult plumage (50 characters), we studied feather pigmentation patterns from different pterylae (feather tracts). A criterion of overlap of basic pigmentation elements was used to assign costs to the transformation between the states in most of these characters in such a way that transformations between more similar conditions were less costly. The consensus tree was almost fully resolved, and about 50% of its groups were relatively well supported. Because the only outgroup that could be used provided a poor root, two possible rootings of the ingroup subtree were considered; in both cases, only one of the two traditional subfamilies (the steppe tinamous) was recovered, and the other (the forest tinamous) appeared as paraphyletic. The results of the present analysis are compared with those from an osteological data set, using a strict supertree technique. The combined tree has a large number of nodes, indicating a high degree of congruence between the two data sets.Fil: Bertelli, Sara Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Giannini, Norberto Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Goloboff, Pablo Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto Superior de Entomología; Argentin

Simultaneously Mapping and Superimposing Landmark Configurations with Parsimony as Optimality Criterion

All methods proposed to date for mapping landmark configurations on a phylogenetic tree start from an alignment generated by methods that make no use of phylogenetic information, usually by superimposing all configurations against a consensus configuration. In order to properly interpret differences between landmark configurations along the tree as changes in shape, the metric chosen to define the ancestral assignments should also form the basis to superimpose the configurations. Thus, we present here a method that merges both steps, map and align, into a single procedure that (for the given tree) produces a multiple alignment and ancestral assignments such that the sum of the Euclidean distances between the corresponding landmarks along tree nodes is minimized. This approach is an extension of the method proposed by Catalano et al. (2010. Phylogenetic morphometrics (I): the use of landmark data in a phylogenetic framework. Cladistics. 26:539–549) for mapping landmark data with parsimony as optimality criterion. In the context of phylogenetics, this method allows maximizing the degree to which similarity in landmark positions can be accounted for by common ancestry. In the context of morphometrics, this approach guarantees (heuristics aside) that all the transformations inferred on the tree represent changes in shape. The performance of the method was evaluated on different data sets, indicating that the method produces marked improvements in tree score (up to 5% compared with generalized superimpositions, up to 11% compared with ordinary superimpositions). These empirical results stress the importance of incorporating the phylogenetic information into the alignment step.Fil: Catalano, Santiago Andres. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Goloboff, Pablo Augusto. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentin

On stability measures and effects of data structure in the recognition of areas of endemism

Incomplete data sampling, bias, and like properties of distribution datasets that potentially introduce uncertainty in biogeographical analyses and blur biogeographical patterns; therefore, it is important to understand their influence. Despite their relevance, these problems have been largely overlooked in biogeography, where concepts such as ambiguity, stability or support have not even been defined. Here, we propose two stability measures for hypotheses of areas of endemism (AEs) and use them to explore the degree to which different structural qualities of data affect the results of analyses of endemism. Our findings suggest that different types of data incompleteness have different effects on the recovery of the species composition and the geographical or spatial structure of AEs, showing that distinct levels of sampling coverage affect the stability of results in different ways. We show that a small proportion of poorly sampled species may have a stronger impact on AEs stability than many species with medium sampling and that excluding poorly sampled species from the analyses does not guarantee more stable results. These results highlight the importance of planning data collection and indicate that, in order to obtain more stable results, focusing on completing the distribution of strongly undersampled species might be preferable to adding records of any species randomly.Fil: Casagranda, Maria Dolores. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Goloboff, Pablo Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentin

New species of Chilean Hexathelidae (Araneae, Mygalomorphae)

Several new species of Hexathelidae Simon (1892) from Chile are described. In Scotinoecus Simon (1892), a new species (S. ruiles) is described using females; a new species (S. major) is proposed for the male previously misidentified as S. cinereopilosus(Simon, 1889), and females are described; the male of S. cinereopilosusis described for the first time. In Mediothele, the female of M. australisis described for the first time, as well as five new species (M. minima,M. linares, M. nahuelbuta,M. anae andM. lagos); all are based solely on females from Southern and Central Chile. The known geographic distributions of both genera are increased.Fil: Ríos Tamayo, Duniesky. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Goloboff, Pablo Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

An optimality criterion to determine areas of endemism

A formal method was developed to determine areas of endemism. The study region is divided into cells, and the number of species that can be considered as endemic is counted for a given set of cells (= area). Thus, the areas with the maximum number of species considered endemic are preferred. This is the first method for the identification of areas of endemism that implements an optimality criterion directly based on considering the aspects of species distribution that are relevant to endemism. The methodis implemented in two computer programs, NDM and VNDM, available from the authors. © 2002 Society of Systematic Biologists.Fil: Szumik, Claudia Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto Superior de Entomología; ArgentinaFil: Cuezzo, Fabiana del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto Superior de Entomología; ArgentinaFil: Goloboff, Pablo Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto Superior de Entomología; ArgentinaFil: Chalup, Adriana Elizabeth. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto Superior de Entomología; Argentin

Prediciendo la incongruencia entre parsimonia y verosimilitud en estudios filologenomicos: apoyo, niveles taxonomicos e incongruencia entre genes

En la actualidad no existen estudios empíricos que usen un número considerable de datasets para determinar los principales causantes de las diferencias entre los resultados de Máxima Parsimonia (MP) y Máxima Verosimilitud (MV) en análisis filogenómicos. En trabajos previos evidenciamos una alta congruencia entre MP y MV para 149 datasets filogenómicos (2.4 movimientos-SPR en promedio) donde en general las diferencias no afectaron las conclusiones de los estudios, y estuvieron asociadas a nodos con bajo apoyo. MP con pesos implícitos en general no produjo mayor congruencia con MV, que MP bajo pesos iguales. Adicionalmente, los taxones con altos niveles de datos faltantes y/o mayores largos de ramas estuvieron involucrados en la mayoría de los nodos incongruentes. En este trabajo por medio de regresiones lineales evaluamos si existe relación entre la incongruencia MP-MV con i) la incongruencia entre los genes de cada dataset, y ii) el nivel taxonómico abordado. Encontramos que la incongruencia entre los genes está significativamente relacionada con la incongruencia MP-MV, mostrando que aquellos nodos incongruentes son generalmente aquellos que están presentes en un bajo porcentaje de los árboles obtenidos a partir de cada gen. No encontramos una relación significativa entre el nivel taxonómico y la incongruencia MP-MV, aunque estudios más detallados deben realizarse. Nuestros resultados sugieren que las topologías de MV y MP para datos filogenómicos son, en la práctica, equivalentes. Además, la integración de diferentes análisis de las características de los datasets podrían permitir predecir la incongruencia entre MP y MV.Fil: Torres Galvis, Ambrosio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Goloboff, Pablo Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Catalano, Santiago Andres. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaXIII Reunión Argentina de Cladística y BiogeografíaSan Miguel de TucumánArgentinaUniversidad Nacional de Tucumán. Facultad de Ciencias NaturalesInstituto Miguel Lill

Potential for Powered Flight Neared by Most Close Avialan Relatives, but Few Crossed Its Thresholds

Uncertainties in the phylogeny of birds (Avialae) and their closest relatives have impeded deeper understanding of early theropod flight. To help address this, we produced an updated evolutionary hypothesis through an automated analysis of the Theropod Working Group (TWiG) coelurosaurian phylogenetic data matrix. Our larger, more resolved, and better-evaluated TWiG-based hypothesis supports the grouping of dromaeosaurids + troodontids (Deinonychosauria) as the sister taxon to birds (Paraves) and the recovery of Anchiornithinae as the earliest diverging birds. Although the phylogeny will continue developing, our current results provide a pertinent opportunity to evaluate what we know about early theropod flight. With our results and available data for vaned feathered pennaraptorans, we estimate the potential for powered flight among early birds and their closest relatives. We did this by using an ancestral state reconstruction analysis calculating maximum and minimum estimates of two proxies of powered flight potential—wing loading and specific lift. These results confirm powered flight potential in early birds but its rarity among the ancestors of the closest avialan relatives (select unenlagiine and microraptorine dromaeosaurids). For the first time, we find a broad range of these ancestors neared the wing loading and specific lift thresholds indicative of powered flight potential. This suggests there was greater experimentation with wing-assisted locomotion before theropod flight evolved than previously appreciated. This study adds invaluable support for multiple origins of powered flight potential in theropods (≥3 times), which we now know was from ancestors already nearing associated thresholds, and provides a framework for its further study. Video Abstract: [Figure presented] Pei et al. use an updated phylogeny of early birds and their closest relatives to reconstruct powered flight potential, showing it evolved at least three times. Many ancestors of the closest bird relatives neared thresholds of powered flight potential, suggesting broad experimentation with wing-assisted locomotion before theropod flight evolved.Fil: Pei, Rui. Institute Of Vertebrate Paleontology And Paleoanthropology Chinese Academy Of Sciences; ChinaFil: Pittman, Michael B.. The University Of Hong Kong; Hong KongFil: Goloboff, Pablo Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Dececchi, T. Alexander. Mount Marty College; Estados UnidosFil: Habib, Michael B.. Natural History Museum Of Los Angeles County; Estados UnidosFil: Kaye, Thomas G.. Foundation For Scientific Advancement; Estados UnidosFil: Larsson, Hans C. E.. Mcgill University; CanadáFil: Norell, Mark A.. American Museum of Natural History; Estados UnidosFil: Brusatte, Stephen L.. University of Edinburgh; Reino UnidoFil: Xu, Xing. Institute Of Vertebrate Paleontology And Paleoanthropology Chinese Academy Of Sciences; Chin