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Recently, many new (extant) mammal species have been named, mostly by raising subspecies to species rank. This is primarily a consequence of the phylogenetic species concept (PSC) that has become very popular over the last few decades. We highlight several cases of splitting and argue that much of this taxonomic inflation is artificial due to shortcomings of the PSC and unjustified reliance on insufficient morphological and/or genetic data. We particularly discourage species splitting based on gene trees inferred from mitochondrial DNA only and phenetic analyses aimed at diagnosability. Uncritical acceptance of new species creates an unnecessary burden on the conservation of biodiversity

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Although low in diversity, megaherbivores (mammals weighting over 10(3) kg) and especially proboscideans have a powerful impact on the structure and dynamics of present-day ecosystems. During the Neogene (23 to 2.6 Ma) of Europe, the diversity and geographic distribution of these megaherbivores was much greater. Nonetheless, their role in past ecosystems is unclear. Nutrition is one of the main bonds between organisms and their environment. Therefore, the ecology of organisms can be inferred from their dietary habits. The present study is aimed at characterizing the feeding habits of diverse megaherbivores through dental microwear analyses. This method was applied on cheek teeth of three sympatric species of proboscideans from the middle/late Miocene of the Molasse Basin in Southern Germany: Gomphotherium subtapiroideum, Gomphotherium steinheimense, and Deinotherium giganteum. The microwear signatures are significantly different between these taxa, suggesting differences in feeding habits and ecological niches within a woodland environment. D. giganteum probably browsed on dicotyledonous foliages whereas the two species of gomphotheres were neither strict grazers nor strict browsers and instead probably fed on a large spectrum of vegetal resources. The differences of occlusal molar morphology between the two gomphotheres are supported by the dental microwear pattern. Indeed, G. subtapiroideum probably ingested more abrasive material than G. steinheimense. Thus, our results suggest that these proboscideans did not compete for food resources.

Given that the biology of the recently extinct aepyornithids is poorly understood, we undertook a histological study of 29 skeletal elements of adult and juvenile specimens of Aepyornithidae, i.e. Aepyornis maximus, Aepyornis hildebrandti and Vorombe titan, in addition to a group of taxonomically unidentifiable juvenile Aepyornithiformes. Comparative analysis of the histology of the different skeletal elements showed that although the femur retained a good record of growth during early ontogeny, the tibiotarsus provided the best record of growth. Our data showed that, like other insular birds and their extant relative, the kiwi, Aepyornithidae experienced protracted growth. We also found that intracortical remodelling began early in ontogeny and continued throughout their lives, becoming more extensive throughout the compacta with age, albeit more restricted to the perimedullary region in the femora. We also deduced that the different skeletal elements experienced variable amounts of intracortical remodelling, which was most likely to be related to biomechanical constraints, size of the element and ontogenetic age. Additionally, we documented the occurrence of an unusual endosteal tissue within the large perimedullary erosional spaces of a femur of A. maximus. Overall, our study provided a lot of new information about the life history of these giant, recently extinct ratites.

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Central Asia is a key area to study the impact of Cenozoic climate cooling on continental ecosystems. One of the best places to search for rather continuous paleontological records is the Valley of Lakes in Mongolia with its outstandingly fossil-rich Oligocene and Miocene terrestrial sediments. Here, we investigate the response by mammal communities during the early stage of Earth’s icehouse climate in Central Asia. Based on statistical analyses of occurrence and abundance data of 18608 specimens representing 175 mammal species and geochemical (carbon isotopes) and geophysical (magnetic susceptibility) data we link shifts in diversities with major climatic variations. Our data document for the first time that the post-Eocene aridification of Central Asia happened in several steps, was interrupted by short episodes of increased precipitation, and was not a gradual process. We show that the timing of the major turnovers in Oligocene mammal communities is tightly linked with global climate events rather than slow tectonics processes. The most severe decline of up 48% of total diversity is related to aridification during the maximum of the Late Oligocene Warming at 25 Ma. Its magnitude was distinctly larger than the community turnover linked to the mid-Oligocene Glacial Maximum.