No abstract

We describe in this paper a new genus and species of cricetid rodent from the Atlantic Forest of Brazil, one of the most endangered eco-regions of the world. The new form displays some but not all synapomorphies of the tribe Oryzomyini, but a suite of unique characteristics is also observed. This new forest rat possesses anatomical characteristics of arboreal taxa, such as very developed plantar pads, but was collected almost exclusively in pitfall traps. Phylogenetic analyses of morphological (integument, soft tissue, cranial, and dental characters) and molecular [nuclear -Interphotoreceptor retinoid binding protein (Irbp) -and mitochondrial -cytochrome bgenes] datasets using maximum likelihood and cladistic parsimony approaches corroborate the inclusion of the new taxon within oryzomyines. The analyses also place the new form as sister species to Eremoryzomys polius, an Andean rat endemic to the Maranon valley. This biogeographical pattern is unusual amongst small terrestrial vertebrates, as a review of the literature points to few other similar examples of Andean-Atlantic Forest pairings, in hylid frogs, Pionus parrots, and other sigmodontine rodents.

Cerradomys is a monophyletic genus that includes four known species, Cerradomys subflavus, C. maracajuensis, C. marinhus, and C. scotti, distributed throughout the open vegetation belt across South America, from northeastern Brazil to southeastern Bolivia, and from eastern to northwestern Paraguay. We revised the status of the species currently assigned to this genus by analyzing skins, skulls, karyotypes, and cytochrome b DNA sequences. We also described two novel species, one distributed in the Brazilian states of Minas Gerais, Bahia, and Sergipe, and the other in the states of Paraíba,

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Aim To infer areas of endemism for the tribe Oryzomyini in South America by employing a database of species richness and geographical distribution, and to compare these results with areas of endemism and species richness proposed in the literature for other taxa. Location We analysed specimens of the tribe Oryzomyini distributed throughout South and Central America, which are housed in European, North and South American museums and collections. Methods We analysed 2768 occurrence records for 102 species of the tribe Oryzomyini using the ndm/vndm algorithm and three different grid sizes to assess the possible effects of grid cell area on the results. Results Using the overlap of consensus areas in South America, we identified three generalized areas of endemism for the Oryzomyini: north‐western South America (NWSA), eastern South American (ESA), and northern South America (NSA); we also identified the Galápagos archipelago (GA) as an area of endemism. Main conclusions Areas of endemism detected in the continental portion of South America include its three main mountain chains: the Andes Cordillera, the Guyanan Shields, and an area east of the Brazilian Shield named Serra do Mar. Each of these regions encompasses many different types of vegetation, and the species richness and composition of the areas of endemism of the tribe are directly related to this environmental diversity. Different grid sizes affected the distributional heterogeneity of the consensus areas. The smallest grid cell size identified mainly Andean areas, which contain a higher number of more exclusive species in a small area along a steep elevational gradient. In contrast, the largest grid size identified areas of endemism along an environmental gradient that co‐varied with latitude and longitude. The identified areas of endemism are corroborated by previous studies on other taxa.

amount of ecological functions, indicating some resistance of species to pressure from the agricultural matrix and advancing urbanization. The amount of ecological functions performed by mammal species within agricultural and fragmented landscapes was similar to pristine areas and more preserved landscapes. Functional connectivity (amount of area assessed for species able to cross 200 m of matrix) was the most plausible model (wAICc = 0.873). Thus, we concluded that improving functional connectivity guarantees high FD values, and we demonstrate the importance of maintaining and restoring structural connections between fragment patches within these landscapes for species conservation and the maintenance of populations over time.

Background: Tree squirrels (Sciuridae, Sciurini), in particular the highly diverse Neotropical lineages, are amongst the most rapidly diversifying branches of the mammal tree of life but also some of the least known. Negligence of this group by systematists is likely a product of the difficulties in assessing morphological informative traits and of the scarcity or unavailability of fresh tissue samples for DNA sequencing. The highly discrepant taxonomic arrangements are a consequence of the lack of phylogenies and the exclusive phenotypic-based classifications, which can be misleading in a group with conservative morphology. Here we used high-throughput sequencing and an unprecedented sampling of museum specimens to provide the first comprehensive phylogeny of tree squirrels, with a special emphasis on Neotropical taxa. Results: We obtained complete or partial mitochondrial genomes from 232 historical and modern samples, representing 40 of the 43 currently recognized species of Sciurini. Our phylogenetic analyses-performed with datasets differing on levels of missing data and taxa under distinct analytical methods-strongly support the monophyly of Sciurini and consistently recovered 12 major clades within the tribe. We found evidence that the diversity of Neotropical tree squirrels is underestimated, with at least six lineages that represent taxa to be named or revalidated. Ancestral state reconstructions of number of upper premolars and number of mammae indicated that alternative conditions of both characters must have evolved multiple times throughout the evolutionary history of tree squirrels.

São Paulo harbors 231 mammal species until now. This is an estimate of its real diversity since many regions of the State continue poorly surveyed, and also reflects the lack of taxonomic work for certain mammal taxa. Nevertheless, our knowledge of the São Paulo mammals has increased in 20% in the last 12 years, especially in relation to bats and rodents. These new data are based in mammal inventories and also in the analysis of specimens housed in scientific collections associated with taxonomic revisions. We also know better about the mammal distribution in the distinct vegetation units present in the State, permitting us to divide the mammals in three distinct components: the most important one is the generalists, represented by species occurring in every landscape in the State, while the second one concentrates species inhabiting the open formations, and the third component the species associated with the forest formations. Besides, the number of studies dealing with the effect of fragmentation and the permeability of mammals in altered areas also has increased. Occurrence, abundance and vulnerability data were essential to raise strategies in order to choose priority areas and to indicate priority actions to conserve the mammals of the State, as well as to classify the species in the different proposed threaten categories, culminating in the List of the Threaten Species of the São Paulo State. However, there are many points yet poorly developed or poorly known, such as the limited number of zoological samples, and the lack of information about the ecology and natural history of many species, respectively. It's extremely important that we increase our samples in the scientific collections, especially in areas of Dense Ombrofilous Forests, in the Cerrado fragments, as well as in central and western areas of the State that continue poorly surveyed. The objective is to produce more taxonomic work in several mammalian groups, and also studies focusing in the phylogeography and in the population genetics in order to effectively diagnose the mammal richness of the State, as well as the evolutionary processes responsible for this diversification. Additionally, ecological data accompanying this information is needed in order to evaluate the conservation status of the São Paulo mammals to decide about the better strategies to manage and conserve these mammals.