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Abstract: The present study compares the forefoot and hindfoot musculature of five representative species of Cavioidea rodents. In all species, the musculature of both forefeet and hindfeet have the same array regardless of the absence of digit I in the manus of Hydrochaeris hydrochaeris and Cavia porcellus. Our results suggest a tendency in these species towards a three-digit system, with a functional loss of digit V and a predominance of digit III in their forefeet. In the same way, the muscular reduction of digit I in the other rodents analyzed indicates a four-digit system with predominance of digit II in Myoprocta acouchy and Dasyprocta leporina and of digit V in Agouti paca. There seems to be an association between the muscular arrangement and functional axis of the foot, raising the general question why this axis runs between the third and forth digit, or along the third digit. [Copyright &y& Elsevier]

The altitudinal gradient found in the Atlantic Forest may play a role in establishing sympatry areas between congeneric species of sigmodontine rodents. For some genera with cryptic species, the elucidation of spatial patterns of distribution may be useful to understand reproductive isolation and speciation patterns, as well as spatial and temporal factors determining the boundaries of species' geographical distributions. Here we evaluated the occurrence of sympatry between Juliomys species along an altitudinal gradient in the Serra da Bocaina National Park (SBNP). Additionally, we review the occurrence of J. rimofrons and add new records of species occurrence in the SBNP, aided by karyological and molecular data. The study was carried out at four sites in the SBNP, which ranged between 770 and 1,200 m a.s.l. We captured 24 Juliomys specimens. Six out of 24 specimens were collected and karyotyped. For J. pictipes, the karyotype had a 2n of 36 and a FN of 34, and for J. ossitenuis 2n of 20 and FN of 36. Seventeen out of 24 Juliomys specimens were used in the cytochrome b phylogeny: 12 specimens grouped with J. pictipes and five with J. ossitenuis. Additionally, a specimen previously identified as J. rimofrons (MN 77793) clustered together with J. pictipes. Juliomys pictipes and J. ossitenuis were found in sympatry in two out of four sites in altitudes higher than 1,000 m a.s.l.. Our karyological and molecular data provided the detection of two Juliomys species in the SBNP for the first time (J. pictipes and J. ossitenuis) and disregarded the previous record of J. rimofrons. Our record of sympatry between J. pictipes and J. ossitenuis represents the fifth known record of sympatry between these species up to date. [ABSTRACT FROM AUTHOR]

Here we report the first record of Drymoreomys albimaculatus Percequillo, Weksler & Costa, 2011 (Cricetidae, Sigmodontinae) in Rio de Janeiro state, Brazil. One specimen was captured at Serra da Bocaina National Park, municipality of Paraty. The specimen was captured in a pitfall trap, in a mixed habitat of forest and bamboo. The karyotype showed 2n = 62 and FN = 62, which is similar to the previously described for the species. [ABSTRACT FROM AUTHOR]

Here we present a commented list of mammals registered in the Serra da Bocaina National Park. Three field trips (February, 2010, and May and July, 2011) were accomplished along the RJ-165 highway in the Municipality of Paraty, State of Rio de Janeiro, Brazil. Forty-eight species belonging to nine orders were recorded. The local mammal fauna could be considered diverse and rich, with some species regarded as biological indicators of habitat quality. Endangered and rare rodent species like Blarinomys breviceps, Juliomys rimofrons, and Thaptomys nigrita were captured. Road and hunting impacts on mammals are discussed. [ABSTRACT FROM AUTHOR]

Until now, Juliomys rimofrons Oliveira and Bonvicino, 2002 has been known only from the type locality, the county of Itamonte, State of Minas Gerais, Brazil. Based on morphological and karyological examinations, in this study we identified two new records for this species. Both records correspond to individuals collected at Serra da Bocaina National Park, in the states of Rio de Janeiro and São Paulo, Brazil. These records increase the species' geographic range southwards, approximately 100 km from the type locality. [ABSTRACT FROM AUTHOR]