Significado paleogeográfico de la presencia de gastrópodos marinos en rocas del Jurásico Temprano (Hettangiano medio) de la Formación Pogibshi, Alaska

A middle Hettangian marine gastropod assemblage is reported from the Kenai Peninsula of south-central Alaska supplying new paleontological evidence of this group in Lower Jurassic rocks of North America. Pleurotomaria pogibshiensis sp. nov. is described from the middle Hettangian marine succession informally known as Pogibshi formation, being the first occurrence of the genus in the Kenai Peninsula and the oldest occurrence of the genus in present-day Alaska and North America. One species of the genus Lithotrochus, namely Lithotrochus humboldtii (von Buch), is also reported for the first time from the Kenai Peninsula. Lithotrochus has been considered as endemic to South America for a time range from the early Sinemurian to the late Pliensbachian. The newest occurrence of Lithotrochus in rocks of the Pogibshi formation extends the paleobiogeographical and chronostratigraphical distribution of the genus into the present-day Northern Hemisphere. However, the Southern Hemisphere affinities are consistent with the hypothetical interpretations (although supported both by paleobiogeographical and paleomagnetic data) that the Peninsular terrane of south-central Alaska is far-traveled and may have originated at much more southerly paleolatitudes than its present-day position. Two other Early Jurassic caenogastropods typical of the Andean region of South America and of the Tethyan epicontinental seas are described for the first time in the Pogibshi formation, and these are Pseudomelania sp. and Pictavia sp. The new gastropod assemblage reported here shows close affinities with coeval South American and European gastropod faunas, supplying new evidence to interpret their distribution during the Early Jurassic.Una nueva asociación de gastrópodos del Hettangiano medio reconocida en la región sur central de Alaska, aporta nueva evidencia paleontólogica sobre la presencia de este grupo en el Jurásico Inferior de América del Norte. Pleurotomaria pogibshiensis sp. nov. está presente en depósitos marinos del Hettangiano medio de la unidad informalmente conocida como formación Pogibshi, y es la primera ocurrencia del género en la Península Kenai y el registro más antiguo para Alaska y Norte América. Una especie del género Lithotrochus, Lithotrochus humboldtii (von Buch), también se reporta por primera vez en Alaska. Lithotrochus ha sido considerado hasta el momento un género endémico de América del Sur para un intervalo de tiempo, que se extiende desde el Sinemuriano temprano al Pliensbachiano tardío. El nuevo registro de Lithotrochus en rocas de la Formación Pogibshi permite extender su distribución paleobiogeográfica y cronoestratigráfica en el actual hemisferio Norte. Sin embargo, las afinidades con el hemisferio Sur están en consonancia con la interpretación (apoyada por datos paleobiogeográficos y paleomagnéticos) de que el territorio peninsular del centro-sur de Alaska es alóctono y pudo haberse originado en paleolatitudes mucho más al sur que su posición actual. Otros dos caenogastrópodos típicos de la región andina de América del Sur y de los mares epicontinentales del Tethys, tales como Pseudomelania sp. and Pictavia sp., se describen por primera vez para el Jurásico Inferior de la formación Pogibshi. La nueva asociación de gastrópodos aquí descrita muestra estrechas afinidades con faunas coetáneas de América del Sur y Europa, lo que otorga nuevas evidencias para interpretar sus patrones de distribución paleobiogeográfica durante el Jurásico temprano.Fil: Ferrari, Silvia Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico de Geología y Paleontología; ArgentinaFil: Blodgett, Robert B.. Blodgett and Associates; Estados UnidosFil: Hodges, Montana S.. California State University Sacramento; Estados UnidosFil: Hodges, Christopher L.. California State University Sacramento; Estados Unido

Cosmopolitan Early Jurassic Marine Gastropods from West-Central Patagonia, Argentina

A new, relatively diverse gastropod fauna is reported from the Chubut province of west−central Patagonia. The gastro− pod association at the “El Córdoba ” fossiliferous locality (Lower Toarcian of Osta Arena Formation) consists of three new species: the eucyclid Amberleya? espinosa sp. nov. and two procerithiids Cryptaulax damboreneae sp. nov. and Cryptaulax nulloi sp. nov. Other members of the association are the ataphrid Striatoconulus sp., discohelicid Colpom− phalus? sp., and an undetermined zygopleurid. Knowledge on Early Jurassic gastropods from South America and other southern continents is reviewed to show that the taxonomic composition of the El Cordoba association strongly resem− bles other gastropod associations of this age (even those from Europe), suggesting a wide distribution of cosmopolita

A Comparative Risk Assessment Of Burden Of Disease And Injury Attributable To 67 Risk Factors And Risk Factor Clusters In 21 Regions, 1990–2010: A Systematic Analysis For The Global Burden Of Disease Study 2010

Background Quantification of the disease burden caused by different risks informs prevention by providing an account of health loss different to that provided by a disease-by-disease analysis. No complete revision of global disease burden caused by risk factors has been done since a comparative risk assessment in 2000, and no previous analysis has assessed changes in burden attributable to risk factors over time

Data from: Early Jurassic Trochotomidae (Vetigastropoda, Pleurotomariodea) from the Neuquén Basin, Argentina

Trochotomidae is a small but distinctive extinct family of pleurotomarioidean gastropods characterized by trochiform shells with an elliptical trema. Two new species of trochotomids are described from Pliensbachian deposits in the Neuquén Basin, Argentina. The new genus-group name Placotoma is proposed to replace the pre-occupied name Discotoma Haber non Mulsant. The record of Trochotoma (Trochotoma) protonotialis new species and Trochotoma (Placotoma) neuquensis new species in the early Jurassic of Argentina extends the paleobiogeographical distribution of the genus (and the family) to the Southern Hemisphere. The new taxa reported here represent a component of the pleurotomarioidean adaptive radiation that took place in the Tethyan region during the earliest Jurassic. They are related to local patch coral reefs of shallow, open-marine paleoenvironments, agreeing with the known habitat of most species of this family. The group was well represented in the Tethyan region during the Mesozoic, especially during the Jurassic, and the new species represent its southernmost occurrence

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Ferrari etal-SupplMateria

Hettangian marine invertebrates from the Kenai Peninsula near Seldovia, Alaska

A sequence of Late Triassic to Early Jurassic marine sedimentary and volcanic deposits compose the sea cliffs west and south of Seldovia on the southwestern portion of the Kenai Peninsula in Alaska. Informally known as the Pogibshi formation and assigned to the island-arc Peninsular terrane, the middle July member of the Pogibshi is an understudied fossiliferous unit perhaps encompassing the Triassic-Jurassic boundary (TJB). A paleontological and geochronological search for the TJB has resulted in the establishment of the earliest Jurassic (Hettangian) pectinid bivalve Weyla (Lywea), solitary stylophyllid scleractinian corals, and gastropods including Pleurotomaria. These fossils are significant because they may be the oldest known Jurassic occurrences in North America. To confirm the age of the fossils, detrital zircons were extracted from two fossiliferous sandstones from an upper potentially Sinemurian location and lower potentially Hettangian location. An analysis of the uranium-lead dates resulted in maximum depositional ages of 198.9 ± 0.62 ± 2.2 and 200.5 ± 2.5 ± 1.8 Ma, respectively. These dates were compared to ages derived from established ammonite zones. The combination of these geochronologic and biochronologic constraints establishes a middle Hettangian age for the fossils occurring at the base of the July member.Fil: Hodges, Montana S.. California State University; Estados UnidosFil: Hodges, Christopher L.. California State University; Estados UnidosFil: Blodgett, Robert B.. Blodgett & Associates; Estados UnidosFil: Stanley, George Jr.. University of Montana; Estados UnidosFil: Ferrari, Silvia Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico de Geología y Paleontología; Argentin

The genera Calliotropis Seguenza and Ambercyclus n. gen. (Vetigastropoda, Eucyclidae) from the Early Jurassic of Argentina

The systematic position of the fossil species referred to Calliotropis is currently under debate due to the striking resemblance between these forms with their extant counterparts in general shell morphology and ornament pattern. We propose two temporal subgenera of Calliotropis: Calliotropis (Riselloidea) for Mesozoic species and Calliotropis (Calliotropis) for Cenozoic and Recent taxa. We also synonymize the families Eucyclidae and Calliotropidae, and redescribe the type genus of Eucylidae based on topotypic material of E. obeliscus from Normandy. We argue that the generic name Amberleya should be restricted to its type species Amberleya bathonica. For the species that were traditionally included in Amberleya, we propose the new genus Ambercyclus, with its type species Amberleya orbignyana. The present paper also provides descriptions of three Calliotropis species from the Early Jurassic marine deposits of Argentina. The occurrence of Calliotropis (Riselloidea) keideli n. sp., Calliotropis (Riselloidea) cf. C. (R.) keideli and Calliotropis (Riselloidea) sp. in the Jurassic of Chubut and Neuquén provinces represents a new record of the genus in Early Jurassic sediments of Argentina and South America. Moreover, two species of Ambercyclus n. gen., such as Ambercyclus espinosus and Ambercyclus? isabelensis n. sp., are described from the same deposits. Eucyclus, Amberleya, Ambercyclus, and Calliotropis are included into Eucyclidae, which we consider to be a family of Seguenzioidea.Fil: Ferrari, Silvia Mariel. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Kaim, Adrzej. Polish Academy Of Sciences; ArgentinaFil: Damborenea, Susana Ester. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin