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Eusmilus shows the most developed sabertoothed adaptations among Nimravidae. This genus is however badly known, especially because it is essentially represented by fragmentary material. Moreover, European specimens mainly belong to the old collections from Quercy whose the precise geographic and stratigraphic origins remain unknown. The discovery several years ago of specimens in Soumailles and Villebramar is therefore particularly important for the knowledge of the genus. The comparative analysis of the new remains assigned to Eusmilus allow to distinguish two species in Western Europe: Eusmilus bidentatus, the type species of the genus, which is present in the Phosphorites of Quercy and in some localities which belong to the mammalian level MP 21 (early Oligocene): the French locality of Soumailles and, in Germany, in the localities of Esclsberg, Möhren 7 and 31. A new form, Eusmilus villebramarensis nov. sp., is present in Villebramar (France, MP 22), in Grafenmühle 6B and Möhren 13 (South Germany, MP 22), and in Kleinblauen (Switzerland, lower Stampian). The skull and dentition of these taxa are described in this study.

We calculate the production rate of soft real photons from a hot quark-gluon plasma using Braaten-Pisarski's perturbative resummation method. To leading order in the QCD coupling constantg we find a logarithmically divergent result for photon energies of ordergT, whereT is the plasma temperature. This divergent behaviour is due to unscreened mass singularities in the effective hard thermal loop vertices in the case of a massless external photon.

We examine again the problem of the damping rate of a moving heavy fermion in a hot plasma within the resummed perturbative theory of Pisarski and Braaten. The ansatz for its evaluation which relates it to the imaginary part of the fermion propagator pole in the framework of a self-consistent approach is critically analyzed. As already pointed out by various authors, the only way to define the rate is through additional implementation of magnetic screening. We show in detail how the ansatz works in this case and where we disagree with other authors. We conclude that the self-consistent approach is not satisfactory.