Miniaturized amphibians of the genus Brachycephalus are phenotypically diverse. The species of Brachycephalus have bufoniform or leptodactyliform Baupläne and any of three skeletal states: nonhyperossified, hyperossified without dorsal shield, and hyperossified with dorsal shield. We integrate highresolution microcomputed tomography, geometric morphometrics, and an estimate of molecular phylogenetic relationships to investigate skull diversity in shape and size-shape space in selected species of Brachycephalus. Skull diversity amongst species of Brachycephalus can be partitioned into shape and size-shape space according to the four conditions of skeletal states-Baupläne, namely, nonhyperossified leptodactyliform, nonhyperossified bufoniform, hyperossified bufoniform without dorsal shield, and hyperossified bufoniform with dorsal shield. Skull diversity in shape and size-shape space in nonhyperossified leptodactyliform species of Brachycephalus is markedly larger, when compared to skull diversity in species of the three other conditions of skeletal states-Baupläne. Variation in skull shape scales with size across Brachycephalus and, therefore, can be explained by allometry. Skull diversity, Baupläne, and skeletal states covary to a large extent with monophyletic lineages of Brachycephalus, as revealed by a mitochondrial DNA species tree. Nonhyperossified bufoniform species and hyperossified bufoniform species with or without dorsal shield are monophyletic lineages, as inferred from a mitochondrial DNA species tree. Nonhyperossified leptodactyliform species of Brachycephalus do not share, however, a most recent common ancestor. The nonhyperossified leptodactyliform species of Brachycephalus, due to their marked skull diversity and lack of monophyly, emerge as evolutionarily complex. Therefore, further sampling of the nonhyperossified leptodactyliform condition of skeletal states-Baupläne will be necessary to further understand the evolutionary history of Brachycephalus.

Indiana limestone is composed mainly of calcite and aragonite minerals, which are different crystalline forms of calcium carbonate. Due to its composition of almost pure calcium carbonate (around 97%), it is widely used in the petroleum industry as a standard porous media for laboratory experiments with a huge scope in industrial applications. A method to improve oil recovery is associated with the use of nanoparticles (NP). One of the most promising is presented to be that of silica (Si) NP, because of their compatibility with the reservoir and subsurface abundance. In this work, we applied Si NP at a concentration of 0.5%, prepared in a base fluid of 1000 ppm in crude oil, injected in Indiana limestone and tested them with microtomography (microCT) and micro x‐ray fluorescence (microXRF) techniques to evaluate the impact of the treatment. Combining morphological results with the mapping of the elements, a more complete characterization of the sample is possible for a better understanding of these interactions applied in oil field industries.

Over the lifetime of an animal, metabolic processes in the body maintain bone tissues in a dynamic state of equilibrium. After the death of the organism, bone tissues undergo diagenesis, an intense transformation that affects its physicochemical constitution. Although many recent works have greatly contributed to the understanding of the processes surrounding diagenesis, there is still much yet to be understood about this multifaceted phenomena. In this work, XRF and microCT were used to characterize the specimen elemental configuration and investigate the fossilization process of a recovered Puma concolor (cranium, mandible and teeth elements), found submerged in a lake in the Impossível‐Ioiô Cave System (Bahia, Brazil). MicroCT enabled the identification of the density distribution throughout the specimens, which were used as reference to XRF analyses. The XRF spectra of the analyzed specimen showed the presence of 11 elements: P, Cl, Ca, Mn, Fe, Cu, Zn, Br, Sr, Y and Hg. Yttrium counts proved to be regular throughout the specimen surface and decreased in the interface between bone surface and interior, evidencing their correspondence to sample environmental exposure. Furthermore, a correlation between fossil surface coloration, element configuration and density is presented. The relatively low presence of Fe and Y in the enamel elicits its elementary and structural preservation. The combined results contribute to the understanding of the physicochemical process of paleomastozoological fossilization, further enriching the comprehension of the process of fossilization in a submerged environment.