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

Elastic and Proton-Dissociative Photoproduction of J/ψJ/\psi Mesons at HERA

Cross sections for elastic and proton-dissociative photoproduction of J/ψ mesons are measured with the H1 detector in positron-proton collisions at HERA. The data were collected at ep centre-of-mass energies s√≈318 GeV and s√≈225 GeV , corresponding to integrated luminosities of L=130 pb−1 and L=10.8 pb−1 , respectively. The cross sections are measured as a function of the photon-proton centre-of-mass energy in the range 25<W γp <110 GeV. Differential cross sections dσ/dt, where t is the squared four-momentum transfer at the proton vertex, are measured in the range |t|<1.2 GeV2 for the elastic process and |t|<8 GeV2 for proton dissociation. The results are compared to other measurements. The W γp and t-dependences are parametrised using phenomenological fits