Los géneros de los Bulimulinae argentinos

Los diversos sistemas de clasificación propuestos para los «Bulimuli» sudamericanos, con sus repetidos cambios en la posición genérica y subgenérica de las especies y los diferentes criterios que se adoptaron para las agrupaciones, han variado tanto como el número de autores que trataron el tema, resultando de ello una gran confusión en el conocimiento sistermático de estos Pulmonados. Muchas de las categorías establecidas, no ofrecían caracteres bien netos y esenciales. Los sistemas, anteriores al que Pilsbry propuso y que fue modificando entre 1896 y 1902, demuestran estar basados en muy limitados materiales y sobre un escaso conocimiento de las áreas de su dispersión geográfica. Este punto de las divisiones genéricas, donde las relaciones no han sido bien aclaradas, contrasta con el de las identificaciones específicas, sobre las cuales, exceptuando algunas formas dudosas, raras o no ilustradas, existen descripciones prolijas y detalladas y una profusa bibliografía. La ambigüedad de los antiguos caracteres que se consignaban como concurrentes en un mismo género, fue suplantada por Pilsbry, por la consideración de la estructura prenatal de la protoconcha, lo que ha permitido diferenciar entidades más naturales. Estos caracteres nepiónicos habían pasado desapercibidos o fueron mal apreciados en los sistemas anteriores, a causa de sus microscópicas proporciones o por la destrucción del ápice en muchísimos especímenes, y también porque muchas veces en los especímenes muy adultos apenas quedan vestigios de ese carácter primitivo. En nuestro estudio hemos de dedicar especial atención a la estructura embrionaria de la conchilla, así como a la distribución geográfica, tratando de definir mejor muchos aspectos sistemáticos hasta ahora obscuros. No es nuestro propósito alcanzar una determinación definitiva acerca de la sistemática y zoogeografía de nuestros Bulimulinae, sino más bien intentar una amplia reconsideración de los conocimientos acumulados sobre este asunto, para rectificarlos o aumentarlos en base al estudio de las amplias colecciones de que disponemos y que incluyen parte de los especímenes «typus».Facultad de Ciencias Naturales y Muse

The family Carditidae (Bivalvia) in the early Danian of Patagonia (Argentina)

The first systematic analysis of the Danian carditids of Patagonia is presented, which includes four genera—one new genus and the first records of three other genera in South America. They consist of Claibornicardia paleopatagonica (Ihering, 1903), a widely distributed species occuring in the Jagüel, Roca and Salamanca formations (Neuquén, Río Negro and Chubut Provinces); Rotundicardia Heaslip, 1968, represented by the new species R. mariobrosorum n. sp., which is restricted to the Roca Formation (Río Negro Province); Cardites feruglioi (Petersen, 1846) (Roca and Lefipán formations, Río Negro and Chubut Provinces); and by Kalelia new genus, which includes K. burmeisteri (Böhm, 1903) from the Salamanca and Roca formations (Río Negro and Chubut Provinces), which is related to the Paris Basin species K. multicostata (Lamarck, 1806) n. comb. and K. pectuncularis (Lamarck, 1806) n. comb. ‘Venericardia’ iheringi (Böhm, 1903), a species known only from internal molds, is described and regarded as a carditid with uncertain affinities. The presence of Claibornicardia, Rotundicardia, and Cardites in Patagonia constitutes the most ancient record of these genera and confirms biogeographical connections previously established between the Danian Argentinian and North American/European fossil faunas.Fil: Perez, Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; ArgentinaFil: del Río, Claudia Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentin

Between seas and continents: aspects of the scientific career of Hermann Von Ihering, 1850-1930

This paper covers some periods in Hermann von Ihering’s scientific trajectory: his training in zoology in Germany and Naples, his international activities based in Brazil, and his return to Germany. It deals with aspects of the formulation of his theories on land bridges. It focuses on the network of contacts he maintained with German émigrés like himself, and primarily with Florentino Ameghino, which allowed him to interact in international scientific circles. It mentions excerpts of his letters and his publications in the periods when he began corresponding with Ameghino (1890), when he travelled to Europe in search of support for his theories (1907), and when he published his book on the history of the Atlantic Ocean (1927).Facultad de Ciencias Naturales y Muse

Biology and conservation of freshwater bivalves : past, present and future perspectives

Freshwater bivalves have been highly threatened by human activities, and recently their global decline has been causing conservational and social concern. In this paper, we review the most important research events in freshwater bivalve biology calling attention to the main scientific achievements. A great bias exists in the research effort, with much more information available for bivalve species belonging to the Unionida in comparison to other groups. The same is true for the origin of these studies, since the publishing pattern does not always correspond to the hotspots of biodiversity but is concentrated in the northern hemisphere mainly in North America, Europe and Russia, with regions such as Africa and Southeast Asia being quite understudied. We also summarize information about past, present and future perspectives concerning the most important research topics that include taxonomy, systematics, anatomy, physiology, ecology and conservation of freshwater bivalves. Finally, we introduce the articles published in this Hydrobiologia special issue related with the International Meeting on Biology and Conservation of Freshwater Bivalves held in 2012 in Braganc¸a, Portugal.We would like to express our gratitude to our sponsors and institutions, especially to the Polytechnic Institute of Braganca for all the logistic support. We acknowledge all keynote speakers, authors, session chairpersons and especially to all attendees whose contributions were fundamental for the success of this meeting. We would also like to thank all referees of this special issue and to Koen Martens, Editor-in-Chief of Hydrobiologia, for all the valuable comments and suggestions. The chronogram was built with the help of the expert opinion of fellow colleagues Rafael Araujo, Arthur Bogan, Kevin Cummings, Dan Graf, Wendell Haag, Karl-Otto Nagel and David Strayer to whom we are very grateful. The authors acknowledge the support provided by Portuguese Foundation for Science and Technology (FCT) and COMPETE funds-projects CONBI (Contract: PTDC/AAC-AMB/117688/2010) and ECO-IAS (Contract: PTDC/AAC-AMB/116685/2010), and by the European Regional Development Fund (ERDF) through the COMPETE, under the project "PEst-C/MAR/LA0015/2011"