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Mass extinctions are major influences on both the phylogenetic structure of the modern biota and our ability to reconstruct broad-based patterns of evolutionary history. The most recent mass extinction is also the most famous—that which implicates a bolide impact in defining the Cretaceous/Palaeogene boundary (K/Pg). Although the biotic effects of this event receive intensive scrutiny, certain ecologically important and diverse groups remain woefully understudied. One such group is the freshwater ray-finned fishes (Actinopterygii). These fish represent 25% of modern vertebrate diversity, yet the isolated and fragmentary nature of their K/Pg fossil record limits our understanding of their diversity dynamics across this event. Here, we address this problem using diversification analysis of molecular-based phylogenies alongside a morphotype analysis of fossils recovered from a unique site in the Denver Basin of western North America that provides unprecedented K/Pg resolution. Our results reveal previously unrecognized signals of post-K/Pg diversification in freshwater clades and suggest that the change was driven by localized and sporadic patterns of extinction. Supported inferences regarding the effects of the K/Pg event on freshwater fish also inform our expectations of how freshwater faunas might recover from the current biodiversity crisis. 

Recent advancements in high-entropy alloys (HEAs) and high-entropy materials (HEMs) show promising potential for different fields of applications. The emergence of HEAs and HEMs has gained significant interest for their exciting nature and properties. As they consist of five or more elements in considerable amounts, properties vary depending on the synergistic effect of combinations of elements. By selecting proper elements and manufacturing methods, better properties can be tuned. Although many unique behaviors of HEAs and HEMs are reported due to their mixing entropy, sluggish diffusion, severe lattice distortion, and multi-metallic cocktail effects, it is necessary to summarize the data to map their feasibility and potential. For example, the combined properties of high thermal stability, thermal fatigue, creep resistance, higher stiffness, and better corrosion resistance for elevated-temperature environments in aerospace applications are pursued. Moreover, gaining the environmental compatibility and longevity of service-life-oxidation behavior of these materials is one of the crucial aspects and, hence, has been recently explored. Therefore, this Research Update aims at summarizing the recent developments and findings in oxidation behavior and highlighting the challenges and controversies for future research perspectives, particularly, on the sustainability for different applications. Moreover, besides the bulk structure, the performance of the HEAs/HEMs coatings is also reviewed.