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The southeastern Atlantic Forest of the Zona da Mata Mineira is located in the extreme north of Minas Gerais state, Brazil. The Serra da Mantiqueira, is a mountainous region with a high diversity of small non-volant mammal species, several of which are rare species or endemic lineages. The presence of cryptic species in small mammals makes the karyotype an excellent tool for identification and detection of new lineages. We analyzed the karyotype of 14 species: 11 rodents – Abrawayaomys ruschii, Akodon cursor, Blarinomys breviceps, Delomys sublineatus, Juliomys ossitenuis, Oligoryzomys nigripes, Oligoryzomys flavescens, Oxymycterus dasytrichus, Rhipidomys tribei, Sooretamys angouya, and Thaptomys nigrita; and three marsupials – Monodelphis scalops, Philander quica, and Marmosops incanus. We described for the first time the fundamental autosomal number and the morphology of sex chromosomes of Abrawayaomys ruschii, a rare sigmodontine species, and described a new karyotype for Blarinomys. The revision of published karyotypes of the species herein studied enabled the expansion of the geographic distribution of Oligoryzomys nigripes and Delomys sublineatus.

Food availability is considered to be a primary factor affecting animal populations, yet few experimental tests have been performed to evaluate its actual importance in species-rich ecosystems such as rainforests. It has been suggested that in such systems certain plant species may act as “keystone” resources for animals, but the importance of presumed keystone resources for populations has not been quantified experimentally. Using complementary seed removal and seed-addition experiments, we determined how the supply of a presumed keystone resource, seeds of Araucaria angustifolia, affects short-term demography of their main consumer group (small rodents) in a biodiversity hotspot, the Brazilian Atlantic Forest. We hypothesized that (i) the harvest of A. angustifolia seeds by human populations has negative impacts on rodents, and (ii) these seeds are a limiting resource for rodent populations. To test these hypotheses, we monitored populations of two species of numerically dominant rodents (Delomys dorsalis and Akodon montensis) within replicated control-experimental plots. Manipulations of seed supply over 2 years had little effect on population size, body condition, survival, or reproduction of the two rodents, suggesting that, in the short-term (within one generation), their populations are not food limited in Araucaria forests. Despite apparently having all the characteristics of a keystone resource, as currently defined in the literature, the seeds of A. angustifolia had limited influence on the short-term demography of their main consumer group. In situations where purported keystone resources are seasonally abundant, their actual importance may be lower than generally assumed, and these resources then may have only localized and temporary effects on consumer populations.

Paraguay, situated in south-central South America, lies at the nexus of several major biomes, and exhibits high species richness for a relatively small country. Nevertheless, that faunal diversity is poorly known, and new species for the country continue to come to light. This paper reports on 3 species of rodents, 1 new for the country and 2 known previously in Paraguay from 1 specimen. We emphasize the need for more and better training of new field and museum biologists, as well as for directors of permitting agencies and protected areas.

The helminth fauna and metacommunity structure of eight sympatric sigmodontine rodents were investigated at the Serra dos Órgãos National Park, an Atlantic Forest reserve located in the State of Rio de Janeiro, southeast Brazil. Rodents of the species Abrawayaomys ruschii, Akodon montensis, Blarinomys breviceps , Delomys dorsalis, Oligoryzomys flavescens, Oligoryzomys nigripes, Oxymycterus quaestor and Thaptomys nigrita were found infected with helminths. Akodon montensis presented the highest total helminth species richness, with six different species of helminths. The nematode Stilestrongylus lanfrediae was the most abundant and prevalent helminth species observed. The host-parasite network analysis showed little interactions among host species. Akodon montensis seems to act as a keystone-species in the rodent community. This species shared the nematodes Stilestrongylus aculeata with A. ruschii and Protospirura numidica criceticola with T. nigrita, and the cestode Rodentolepis akodontis with D. dorsalis. The congeners host species O. flavescens and O. nigripes shared the nematodes Guerrerostrongylus zetta and S. lanfrediae. The rodents B. breviceps and O. quaestor did not share any helminths with other hosts. The helminth metacommunity showed a random pattern on both infracommunity and component community levels, indicating different responses by each helminth species to the environmental gradient. Resumo Foram investigadas a helmintofauna e suas estruturas da metacomunidade em oito roedores sigmodontíneos simpátricos ao longo do Parque Nacional da Serra dos Órgãos, uma reserva de Mata Atlântica no estado do Rio de Janeiro, Brasil. Roedores das espécies Abrawayaomys ruschii, Akodon montensis, Blarinomys breviceps, Delomys dorsalis, Oligoryzomys flavescens, Oligoryzomys nigripes, Oxymycterus quaestor e Thaptomys nigrita foram infectados por helmintos. Akodon montensis apresentou a maior riqueza total de espécies de helmintos, com seis espécies. O nematoide Stilestrongylus lanfrediae foi a espécie de helminto com maior abundância e prevalência. A análise de rede parasito-hospedeiro mostrou poucas interações entre as espécies hospedeiras e A. montensis atuou como uma espécie-chave na comunidade de roedores. Esta espécie compartilhou os nematoides Stilestrongylus aculeata com A. ruschii e Protospirura numidica criceticola com T. nigrita, e o cestoide Rodentolepis akodontis com D. dorsalis. As espécies congêneres O. flavescens e O. nigripes compartilharam os nematoides Guerrerostrongylus zetta e S. lanfrediae. Os roedores B. breviceps e O. quaestor não compartilharam helmintos com outros hospedeiros. A metacomunidade de helmintos mostrou um padrão aleatório em ambos os níveis, comunidade componente e infracomunidade, indicando diferentes respostas de cada espécie de helminto ao gradiente ambiental.

363. Pallid Atlantic Forest Rat Delomys sublineatus French: Délomys pale / German: Fahle Atlantische Waldratte / Spanish: Rata de bosque atlantico palida Other common names: Pallid Delomys Taxonomy. Oryzomys sublineatus Thomas, 1903, “Engenheiro Reeve [= Rive], Inland of Victoria, Prov. Espiritu [= Espirito] Santo, Brazil. Alt. 500 m. ” This species is monotypic. Distribution. Atlantic Forest of SE Brazil. Descriptive notes. Head-body 126-146 mm, tail 106-127 mm, ear 20-22 mm, hindfoot 28-30 mm; weight 41-60 g (mean 50 g). Dorsal pelage of the Pallid Atlantic Forest Rat is coarse and short. It usually lacks distinct mid-dorsal stripe and almost always has lateral line of clear yellow or buff separating dorsum and venter. Mystacial vibrissae are short, not extending to tips of pinnae when laid back alongside head. Hindfeet are covered dorsally with (usually) pure white hairs. Tail is strongly bicolored. Eight mammae present. Chromosomal complement is 2n = 72, FN = 90. Habitat. Montane and pre-montane forest and mixed-coniferous forest from near sea level to elevations of ¢.1200 m. The Pallid Atlantic Forest Rat appears to prefer intact native forests compared to forest fragments. Food and Feeding. No information. Breeding. No information. Activity patterns. The Pallid Atlantic Forest Rat is nocturnal. Morphological characteristics (e.g. shorter vibrissae,tail, and fifth pedal digits) suggest that the Pallid Atlantic Forest Rat might be less scansorial than the Striped Atlantic Forest Rat (D. dorsalis) and also slightly subterranean. Movements, Home range and Social organization. Mean maximum distance moved from a original capture site was less than 50 m. Status and Conservation. Classified as Least Concern on The [UCN Red List. The Pallid Atlantic Forest Rat has a wide distribution and presumably large overall population. It appears to be sensitive to forest fragmentation, with local abundance decreasing in smaller or more isolated patches. Bibliography. Davis (1945), Pardini et al. (2005), Puttker, Bueno et al. (2013), Puttker, MeyerLucht & Sommer (2006, 2008a, 2008b), Puttker, Pardini et al. (2008), Umetsu & Pardini (2007), Voss (1993, 2015a)., Published as part of Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Cricetidae, pp. 204-535 in Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona :Lynx Edicions on page 412, DOI: 10.5281/zenodo.6707142

362. Montane Atlantic Forest Rat Delomys altimontanus French: Délomys montagnard / German: Atlantische Bergwaldratte / Spanish: Rata de bosque atlantico de montana Other common names: Montane Delomys Taxonomy. Delomys altimontanus P. R. Goncalves & J. A. Oliveira, 2014, Campos do [tatiaia, 2450 m, Itatiaia National Park, Rio de Janeiro, Brazil. This species is monotypic. Distribution. Restricted to Mantiqueira Mts (Caparao and Itatiaia Mts) in SE Brazil. Descriptive notes. Head-body 130-134 mm, tail 123-126 mm, ear 20-22 mm, hindfoot 31-32 mm; weight 25-72 g (mean 45 g). The Montane Atlantic Forest Rat is a medium-sized species of Delomys, with soft and long dorsal pelage, predominantly cinnamon-brown grizzled with yellow but becoming brighter orange along flanks. Tail is as long as head-body length and strongly bicolored throughout most ofits length. Six mammae are present. Chromosomal complement is 2n = 82 and FN = 86. Habitat. Humid montane forests and shrublands in the Caparaé mountain range at elevations above 1800 m and forested habitats near streams and never on open mesas in the Itatiaia mountain range above 2100 m. Food and Feeding. No information. Breeding. No information. Activity patterns. The Montane Atlantic Forest Rat is probably nocturnal. Movements, Home range and Social organization. No information. Status and Conservation. Not assessed on The [UCN Red 1st. Bibliography. Bonvicino et al. (1997), Gongalves & Oliveira (2014)., Published as part of Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Cricetidae, pp. 204-535 in Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona :Lynx Edicions on page 412, DOI: 10.5281/zenodo.6707142

362. Montane Atlantic Forest Rat Delomys altimontanus French: Délomys montagnard / German: Atlantische Bergwaldratte / Spanish: Rata de bosque atlantico de montana Other common names: Montane Delomys Taxonomy. Delomys altimontanus P. R. Goncalves & J. A. Oliveira, 2014, Campos do [tatiaia, 2450 m, Itatiaia National Park, Rio de Janeiro, Brazil. This species is monotypic. Distribution. Restricted to Mantiqueira Mts (Caparao and Itatiaia Mts) in SE Brazil. Descriptive notes. Head-body 130-134 mm, tail 123-126 mm, ear 20-22 mm, hindfoot 31-32 mm; weight 25-72 g (mean 45 g). The Montane Atlantic Forest Rat is a medium-sized species of Delomys, with soft and long dorsal pelage, predominantly cinnamon-brown grizzled with yellow but becoming brighter orange along flanks. Tail is as long as head-body length and strongly bicolored throughout most ofits length. Six mammae are present. Chromosomal complement is 2n = 82 and FN = 86. Habitat. Humid montane forests and shrublands in the Caparaé mountain range at elevations above 1800 m and forested habitats near streams and never on open mesas in the Itatiaia mountain range above 2100 m. Food and Feeding. No information. Breeding. No information. Activity patterns. The Montane Atlantic Forest Rat is probably nocturnal. Movements, Home range and Social organization. No information. Status and Conservation. Not assessed on The [UCN Red 1st. Bibliography. Bonvicino et al. (1997), Gongalves & Oliveira (2014).

364. Striped Atlantic Forest Rat Delomys dorsalis French: Délomys sombre / German: Gestreifte Atlantische Waldratte / Spanish: Rata de bosque atléantico rayada Other common names: Striped Delomys Taxonomy. Hesperomys dorsalis Hensel, 1873, “Stiden Brasiliens.” Restricted by F. D. de Avila-Pires in 1994 to “Taquara, Rio Grande do Sul, Brasil.” Delomys dorsalis is the type species of the genus. A thorough revision by P. R. Goncalves and J. A. Oliveira in 2014 recommended dismissing recognition of subspecies based on morphological grounds, ranking D. dorsalis collinus a junior synonym of D. dorsalis. Monotypic. Distribution. Atlantic Forest of SE & S Brazil and NE Argentina, mostly along coastal mountains. Descriptive notes. Head—body 104-135 mm, tail 100-145 mm, ear 21-22 mm, hindfoot 25-31 mm; weight 20-56 g (mean 38 g). The Striped Atlantic Forest Rat is medium-sized species of Delomys, with soft and dense dorsal pelage, predominantly dark cinnamon-brown and without bright yellow lateral line or patch;tail as long as head-body length. Vibrissae are long, extending to or beyond tips of pinnae when laid back along head. There are 6-8 mammae. Chromosomal complement is 2n = 82, FN = 80. Habitat. Submontane and montane forests frequently associated with Araucaria angustifolia (Araucariaceae) from sea level to elevations above 2000 m. Food and Feeding. The Striped Atlantic Forest Rat eats fruits, seeds, invertebrates, and fungi. Breeding. Striped Atlantic Forest Rats are reproductively active year-round, although breeding activity is reduced in winter. Postpartum estrus occurs, gestation lasts 21-22 days, and litters have 2-5 young. Activity patterns. The Striped Atlantic Forest Rat is nocturnal. It is reported to be primarily terrestrial, although individuals have remarkable scansorial abilities and can seasonally occur in subcanopy vegetation. Movements, Home range and Social organization. Striped Atlantic Forest Rats move among and shelter in clutters of logs, organic debris, mossy roots, tangled bamboo, and herbaceous understory rather than frequenting open areas on forest floor. Apparently, Striped Atlantic Forest Rats experience peaks of abundance related to availability of seeds of Araucaria angustifolia in mixed forests with conifers. Status and Conservation. Classified as Least Concern on The IUCN Red List. The Striped Atlantic Forest Rat has a wide distribution and presumably large overall population. Bibliography. de Avila-Pires (1994), Bonvicino & Geise (1995), Cademartori (2002), Cademartori et al. (2004, 2005), Dalmagro & Vieira (2005), Goncalves & Oliveira (2014), Hershkovitz (1998), Massoia (1962), Thomas (1917b), Vieira et al. (2006), Voss (1993, 2015a)., Published as part of Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Cricetidae, pp. 204-535 in Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona :Lynx Edicions on pages 412-413, DOI: 10.5281/zenodo.6707142

A new species, Androlaelaps delomys n. sp., (Acari: Mesostigmata: Laelapidae) is described from the sigmodontine rodent, Delomys dorsalis, collected in the Boraceia Biological Station in the state of Sao Paulo, Brazil. This mite is associated with the endemic rodent genus Delomys throughout the Atlantic Forest region of southeastern Brazil.

Apresentamos a assembleia de sigmodontíneos do Holoceno inferior e médio registrada no sítio arqueológico RS-TQ-58: Afonso Garivaldino Rodrigues (Município de Brochier, Estado do Rio Grande do Sul). Um total de 16 espécies foram detectadas pelo estudo de 572 espécimes, sendo quase metade destes pertencente a tribo Akodontini. Esta assembleia inclui espécies tipicamente de áreas abertas (e.g. Calomys sp., Gyldenstolpia sp., Kunsia tomentosus) e outras consideradas florestais (e.g. Delomys sp., Juliomys sp., Sooretamys angouya). Necromys obscurus, sigmodontíneo atualmente restrito à Argentina Central e sul do Uruguai, está presente de forma abundante no sítio Garivaldino e é registrado pela primeira vez para o Quaternário do Brasil. Thaptomys nigrita e Wilfredomys oenax tem seus primeiros registros para o Holoceno do Estado do Rio Grande do Sul. Em comparação com a assembleia atual de roedores sigmodontíneos conhecida para o Rio Grande do Sul, Pseudoryzomys simplex, K. tomentosus, N. obscurus e Gyldenstolpia sp. tornaram-se regionalmente extintos. A assembleia de sigmodontíneos registrada no Garivaldino é mais rica do que outra previamente estudada proveniente do sítio Pilger. A evidência de ambos os sítios reflete mudanças na composição de espécies, a qual pode estar relacionada com uma transformação progressiva da paisagem, de campos abertos para florestas. We present the sigmodontine assemblage from lower and middle Holocene recorded in the archaeological site RS-TQ-58: Afonso Garivaldino Rodrigues (County of Brochier, State of Rio Grande do Sul). A total of 16 species are detected from the study of 572 specimens, about half of which belonging to the tribe Akodontini. The assemblage recorded include species which typically inhabit open areas (e.g. Calomys sp., Gyldenstolpia sp., Kunsia tomentosus) and also several considered as forest dewellers (e.g. Delomys sp., Juliomys sp., Sooretamys angouya). Necromys obscurus, a sigmodontine today restricted to Central Argentina and Southern Uruguay, is abundantly recorded in Garivaldino and reported for the first time to the Quaternary from Brazil. Thaptomys nigrita and Wilfredomys oenax have in Garivaldino their first records to the Holocene from Rio Grande do Sul State. Compared to the recent assemblage of sigmodontine rodents recorded in Rio Grande do Sul, Pseudoryzomys simplex, K. tomentosus, N. obscurus and Gyldenstolpia sp. became regionally extinct. The sigmodontine assemblage detected in Garivaldino is richest than a previously studied one from Pilger site. The evidence of both sites reflects changes in the species composition, which can be linked with a progressive transformation of the general landscape from mostly open grasslands to forests. Fil: Stutz, Narla Shannay. Universidade Federal de Santa Catarina; Brasil Fil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; Argentina Fil: Hadler, Patrícia. Universidade Federal de Santa Catarina; Brasil

RESUMO Das 1.361 espécies de vertebrados que a Mata Atlântica abriga, 567 são endêmicas. Rodentia e Didelphimorphia somam 71% dos endemismos observados para mamíferos nesse bioma. No Brasil, esses animais ainda carecem de informações básicas a cerca de sua biologia, distribuição, e mesmo riqueza total. Esse trabalho objetivou identificar as espécies de marsupiais e roedores do Parque Estadual Rio da Onça e caracterizar a morfologia dos pelos-guarda e do conjunto cromossômico das mesmas, além de verificar a composição de pequenos mamíferos não voadores em diferentes ambientes e estratos vegetais. Foram realizadas treze campanhas de campo e como esforço adicional, três linhas de armadilhas de queda foram instaladas. O esforço amostral total foi de 6.633 armadilhas e 1.181 baldes distribuídos ao longo de 69 noites de amostragem, que resultaram em 196 capturas de 166 indivíduos de 12 espécies. Foram registradas sete espécies da Ordem Rodentia: Akodon montensis, Delomys sublineatus, Euryoryzomys russatus, Juliomys pictipes, Nectomys squamipes, Oligoryzomys nigripes e Thaptomys nigrita, além de cinco espécies de marsupiais da Ordem Didelphimorphia: Didelphis aurita, Gracilinanus microtarsus, Metachirus nudicaudatus, Marmosa paraguayana e Monodelphis iheringi. Os resultados tricológicos e citogenéticos foram condizentes com os disponíveis na literatura. Quanto à estratificação vertical, somente sete capturas foram feitas em árvore: quatro da espécie Marmosa paraguayana, duas de Didelphis aurita e uma de Akodon montensis. Portanto, para o ambiente de Terras Baixas da área de estudo, a amostragem realizada no extrato arbóreo e arbustivo do sub-bosque não contribuiu para o incremento da lista de espécies.

Apesar do recente incremento ao conhecimento dos pequenos mamíferos do Holoceno do Rio Grande do Sul e da sua importância como indicadores paleoambientais, a maioria das assembleias advindas de sítios arqueológicos permanece sem uma análise detalhada. Este trabalho estuda a fauna de pequenos mamíferos do sítio arqueológico RS-C-61: Adelar Pilger, Município de Harmonia, o qual apresenta evidênci as de ocupação humana contínua ao longo do Holoceno, de cerca de 8.000 anos AP até 3.000 anos AP. A associação fauní stica do sítio está composta por 25 táxons, incluindo cinco marsupiais didelfídeos, 15 roedores cricetídeos e cinco caviomorfos. A maioria dos marsupiais é também encontrada em outros dois sítios próximos, Afonso Garivaldino Rodrigues e Sangão. Entre os cricetídeos, Gyldenstolpia, Kunsia e Oxymycterus são registrados pela primeira vez para o Quaternário do Rio Grande do Sul. Por outro lado, a assembleia de caviomorfos do sítio Pilger é menos diversa do que aquelas dos sítios Afonso Garivaldino Rodrigues e Sangão. O sítio Pilger inclui tanto pequenos mamíferos de ambientes abertos (e.g. Thylamys, Calomys, Cavia), quanto florestais (Delomys, Sooretamys e Phyllomys), ambientes também indicados pelos dados palinológicos. Três caviomorfos (Euryzygomatomys mordax, Dicolpomys fossor e Clyomys riograndensis) estão extintos e, em comparação com a fauna recente das florestas estacionais do Rio Grande do Sul, outros três táxons (Gyldenstolpia sp., Kunsia tomentosus e Pseudoryzomys simplex) sofreram extinções regionais. Despite the increase in knowledge about small mammals from the Holocene of Rio Grande do Sul State and their importance as paleoenviron mental indicators, most assemblages from archaeological sites remains without a detailed analysis. This paper studies the rich small mammals content recovered from the archaeological site RS-C-61: Adelar Pilger, Harmonia, which shows evidence of continuous human occupation throughout the Holocene, from about 8,000 years BP to 3,000 years BP. The assemblage of this site is composed of 25 taxa, including five didelphid marsupials, 15 cricetid and five caviomorph rodents. Most marsupials are also registered in two other sites, Afonso Garivaldino Rodrigues and Sangão. Among Cricetidae, Gyldenstolpia, Kunsia and Oxymycterus are first recorded for Quaternary of Rio Grande do Sul State. On the other hand, the caviomorph assemblage of Pilger site is less diverse than those of the Afonso Garivaldino Rodrigues and Sangão sites. Pilger site includes both small mammals of open (e.g. Thylamys, Calomys, Cavia) and forest (Delomys, Sooretamys and Phyllomys) environments, also supported by palynological data. Three caviomorph (Euryzygomatomys mordax, Dicolpomys fossor and Clyomys riograndensis) are extinct and, compared to the recent fauna of seasonal forest of Rio Grande do Sul, three other taxa (Gyldenstolpia sp., Kunsia tomentosus and Pseudoryzomys simplex) suff ered regional extinctions. Fil: Hadler, Patricia. Universidade Federal de Santa Catarina; Brasil Fil: Cherem, Jorge José. Universidade Federal de Santa Catarina; Brasil Fil: Turbay, Renata. Universidade Federal de Santa Catarina; Brasil Fil: Alberti, Arthur. Universidade Federal de Santa Catarina; Brasil Fil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; Argentina

Estimators of home-range size require a large number of observations for estimation and sparse data typical of tropical studies often prohibit the use of such estimators. An alternative may be use of distance metrics as indexes of home range. However, tests of correlation between distance metrics and home-range estimators only exist for North American rodents. We evaluated the suitability of 3 distance metrics (mean distance between successive captures [SD], observed range length [ORL], and mean distance between all capture points [AD]) as indexes for home range for 2 Brazilian Atlantic forest rodents, Akodon montensis (montane grass mouse) and Delomys sublineatus (pallid Atlantic forest rat). Further, we investigated the robustness of distance metrics to low numbers of individuals and captures per individual. We observed a strong correlation between distance metrics and the home-range estimator. None of the metrics was influenced by the number of individuals. ORL presented a strong dependence on the number of captures per individual. Accuracy of SD and AD was not dependent on number of captures per individual, but precision of both metrics was low with numbers of captures below 10. We recommend the use of SD and AD instead of ORL and use of caution in interpretation of results based on trapping data with low captures per individual.

Tunga bossii new species of tungid sand flea belonging to the caecata group is described with illustrations of the adult female, parasitizing the wild rodent Delomys dorsalis (Hensel) from Brazilian Atlantic Forest. Tunga bossii differs from the ten other known species of Tunginae by the size of the first segment of the maxillary palp and the presence of two bristles at the base of the maxilla. Tunga bossii also can be differentiated from other species of the T. caecata group by the eye morphology. A key to the adult species and neosomes of the genus Tunga also is included.

Quantitative real-time RT-PCR (qRT-PCR) is a sensitive technique for gene expression analysis. A critical factor for creating reliable data in relative quantification is the normalization of the expression data of genes of interest. Therefore the needed normalization factor is calculated out of the expression data of co-amplified genes that are stable expressed in the certain sample material, the so-called reference genes. In this study, we demonstrate the important process of validating potential reference genes using a non-model species. As there are almost no sequences known of the Pallid Atlantic Forest Rat (Delomys sublineatus), a rodent used as indicator species in conservation studies of the endangered Brazilian rainforest, suitable primer sets are more problematic to find than in model species. Out of nine tested primer sets designed for the fully sequenced Mus musculus, five could be used for the establishment of a proper running SYBR-Green assay and validation of their constant expression. qRT-PCR results of 12 cDNAs of Delomys livers were analyzed with three different validation software programs: BestKeeper, NormFinder and geNorm. Our approach showed that out of the five (Sdha, Canx, Pgk1, Actb and Actg1) potential reference genes, the first four should be used for accurate normalization in further relative quantification analyses. Transferring data from close-by model organisms makes high sensitive real-time RT-PCR applicable even to free-ranging non-model organisms. Our approach might be suitable for other non-model organisms.

We investigated the population density of the two common rodent species Akodon montensis, Oligoryzomys nigripes, and the more specialized endemic Delomys sublineatus in secondary forest fragments of the highly endangered coastal Atlantic Rainforest. Linear regression was used to examine relationships between population density and four landscape variables. We tested the hypothesis that rare species, which are more affected by fragmentation than the common species, should decrease in population density with decreasing fragment size while the density of common generalist species should be unaffected or increase in smaller fragments. The results revealed that A. montensis and O. nigripes showed no significant association to any landscape variable. The density of D. sublineatus showed a strong tendency to a positive correlation to fragment size as well as a negative correlation to edge density. The results underline the importance of large and connected forest remnants in the Atlantic Rainforest to guarantee ...

Delomys altimontanus, new species Delomys collinus: Bonvicino & Geise 1995 (not collinus Thomas 1917) Delomys dorsalis: Hershkovitz 1998 (not dorsalis Hensel 1972) Delomys sublineatus: Hershkovitz 1998 (not sublineatus Thomas 1903) Type material. The holotype, MN 69746, is an adult male collected by Pablo R. Gonçalves, João A. Oliveira, Cibele R. Bonvicino and Maria Olímpia G. Lopes on 28 November 2004 (field number JAO 1558). The specimen was collected in a Sherman™ trap placed in a montane shrub dominated by bamboo at the margin of the Campo Belo stream, close to the Abrigo Rebouças. The specimen consists of a skin, skull and postcranial skeleton accompanied by a liver tissue sample preserved in ethanol and femoral medullar cells preserved in methanol/acetic acid solution. We designate as paratypes seven specimens collected in the localities of Abrigo Rebouças (MN 69712, male) at Itatiaia -, Rio de Janeiro state, and Brejo da Lapa (MN 60573 -60576, 60584, 60585), municipality of Itamonte, Minas Gerais state. Type locality. Campos do Itatiaia, (22 ° 23 ’ 26 ”S, 44 ° 40 ’ 14 ”W, 2450m altitude), near Abrigo Rebouças, Parque Nacional do Itatiaia, municipality of Itatiaia, Rio de Janeiro state, Brazil (locality 21, Figs. 1 and 12 a). Etymology. The specific epithet altimontanus refers to the restricted altitudinal distribution of the species, exclusively inhabiting the forested altiplano of the Mantiqueira mountain range in southeastern Brazil (from the Latin altus = high + montanus = mountain inhabitant). Distribution. This species exhibits a disjunct distribution with reported populations apparently restricted to the highest altitudinal forested zones of 1800 to 2500 m in the Itatiaia and Caparaó mountain ranges, which are two different offshoots of the Mantiqueira mountain complex. Populations of Delomys that have been sampled in the intervening mountain chains that are part of the coastal Serra do Mar mountain complex, such as the Serra da Bocaina, Serra dos Órgãos and Serra do Desengano (in Rio de Janeiro state), or even in lower mountains of the Mantiqueira complex (Serra do Brigadeiro in Minas Gerais state), have been identified as either D. dorsalis or D. sublineatus (Delciellos et al. 2012; Modesto et al. 2008; Moreira et al. 2009; Olifiers et al. 2007). These facts suggest that the current disjunct distribution of Delomys altimontanus sp. nov. is a relict of a formerly wider distribution rather than a sampling artifact across Southeastern Brazil. It is probable that additional populations of D. altimontanus occur throughout the Mantiqueira range, especially in the mountains adjacent to Itatiaia that extend to the southwestern into São Paulo state (Campos do Jordão, Piquete) and Minas Gerais (e.g., Itamonte, Delfim Moreira, Passa Quatro). Nevertheless, available samples from these localities do not show the diagnostic morphological or genetic characters of D. altimontanus, rather representing D. dorsalis populations. Karyotype. The karyotype of Delomys altimontanus (Fig. 9) exhibits 2 n = 82 and FN= 86, with an autosomal complement constituted by 3 pairs of biarmed chromosomes, 27 pairs of acrocentrics, a large-sized submetacentric X chromosome and a small metacentric Y chromosome, as previously described by Bonvicino & Geise (1995). Delomys altimontanus diverges from D. sublineatus (2 n= 72, FN= 90) in both diploid and fundamental numbers, but shares the same diploid number with D. dorsalis (2 n= 82), from which it can be distinguished by the morphology of three small-sized biarmed pairs of autosomes. This karyological difference between Delomys altimontanus and D. dorsalis probably evolved through pericentric inversions involving the smallest pairs of autosomes. Diagnosis. A medium-sized species of the genus Delomys with soft and long dorsal pelage, predominantly cinnamon-brown grizzled with yellow, but becoming brighter orange along the flanks; tail as long as head-andbody length and strongly bicolor throughout most of its length; skull with pronounced rostrum and elongated nasal tube projecting beyond the gnathic process; relatively longer and wider molar series than in other congeneric taxa; relatively narrow interorbit; supraorbital region exhibiting the fronto-parietal (coronal) suture collinear with the fronto-squamosal suture, without an area of dorsal contact between squamosal and frontal; incisive foramina with straight margins along the maxillary; mesopterygoid fossa equally wide at its anterior and posterior portions; mandible with wide, shallow and symmetrically excavated sigmoid notch, delicate coronoid process and reduced angular process; karyotype with 2 n= 82 and FN= 86. Description. Body pelage soft, dense and long, with guard hairs along the cervical region of the dorsum varying in length from 15 to 20 mm. General dorsal color is cinnamon-brown in adults, brighter and orangish along the laterals and gradually darker towards the mid-dorsum, generally forming a ill-defined median stripe in most specimens, which extends from the nape to the base of tail (Fig. 10). In old adults the sides of body are more rusty colored due to the presence of bright orange bands on hairs, while young specimens generally display a duller and grayer dorsal and lateral color with few traces of yellowish tone. Ventral pelage predominantly white, covered by whitish hairs with wide dark-gray bases frequently showing through. Head similar in coloration to the mid-dorsum, becoming brighter at the cheeks. Neck and chin region covered by smaller bicolored hairs, similar in coloration to those of the ventral region. Eyes large and surrounded by short dark hairs, forming a narrow eye-ring. Mystacial, superciliary, genal, submental, interramal and carpal vibrissae present. Mystacial vibrissae long, with the two longest reaching the distal tip of the pinnae when laid back. Pinnae large (Table 4) and sparsely covered with short hairs on its internal surface, but more densely furred on its dorsal surface. Cheiridia dorsally covered by short whitish hairs, most of them with dark bases, specially at the proximal metacarpal and metatarsal regions, giving a general soiled or gray aspect to the dorsal surfaces of manus and pes. Hindfoot long and narrow. Ungual tufts long and conspicuous, completely enclosing the claws on digits I–IV, but reduced or vestigial on digit V. Middle digits (II–IV) are longer than the outer digits (I and V), with digit III slightly longer than digits II and IV. Digit I is longer than digit V, with its claw extending to the middle of the first phalange of digit II, while the claw of digit V reaches the first interphalangeal joint of digit IV. Plantar surface naked over the heel and much of the metatarsal region, being more squamate over the digits surface. Six fleshy plantar pads present (hypothenar, thenar and four interdigital pads). Tail slightly longer to, or as long as, the head and body length (Table 4), sparsely covered by short hairs, and displaying a bicolor pattern throughout more than half of its length. The tail color is predominantly dark brown throughout its entire dorsum, but markedly whitish to buffy in the venter, throughout its first two proximal thirds, gradually intergrading to dark-brown towards the distal third. The brighter ventral color of the tail is provided by entirely whitish short hairs, which in the base of the tail span two to three scales in length. Towards the tail dorsum and the distal third of the tail venter, hairs with wide dark brown basal bands become more common, providing darker tones. Six mammae present in lactating females, distributed in inguinal, abdominal and postaxial pairs (pectoral pair lacking), displaying the mammary formula of 0/ 2 / 2 / 2. Cranium large and wide (CIL = 31.4 – 27mm, BB = 12.73 – 11.7mm, Table 4), with a narrow and elongated rostrum, biconcave and narrow interorbit and globular braincase with smooth edges (Fig. 11). Nasals long (NL = 14.65 – 11.75mm) and narrow, extending posteriorly beyond the fronto-premaxillary suture. The nasals taper more abruptly at their anterior midlength and then more subtly before converging at the fronto-nasal suture. Lacrimals squared and relatively large, contacting both the frontal and maxillary bones. Interorbital region relatively narrow and biconcave, exhibiting the typical “hourglass” morphology (Voss 1993) with smooth edges and without supraorbital crested margins, even in older adults. Fronto-nasal suture slightly depressed, with frontal sinuses dorsally prominent. Fronto-parietal (=coronal) suture U-shaped, generally open angled in most specimens, but also sharply angled in some older adults, especially towards its lateral limits. Fronto-parietal and fronto-squamosal sutures collinear, as both the parietal and squamosal bones contact the frontal nearly at the same level along the postorbital wall, leaving no area for a contact between the squamosal and the dorsal surface of the frontal. Parietals wide and slightly expanded onto the lateral surface of the braincase near the squamosal root of the zygomatic arch. Interparietal moderately wide and semicircular, not contacting the squamosal laterally. Zygomatic plate broad and projected anteriorly to the base of the lacrimal capsule, forming a conspicuous zygomatic notch; its anterodorsal margin smoothly rounded. Posterior margin of the zygomatic plate situated anterior to the alveolus of M 1. Zygomatic arch laterally expanded, formed by a large jugal and non-overlapping maxillary and squamosal branches. Postorbital wall with small ridges near the squamosal root of the zygomatic arch, and a conspicuous buccinator-masticatory trough. Incisive foramina wide, with an inflated and expanded palatine process and reduced maxillary septum; lateral outlines of the incisive foramina are straight lined along their maxillary portions, being sharply bent only at their caudal ends, where they terminate anterior to the M 1 alveolus. Palate surface flat, without expressive lateral troughs or posterolateral pits. Bony palate short, with the mesopterygoid fossa extending anteriorly between the molar rows; anterior margin of the mesopterygoid fossa biconcave in most specimens due to the presence of a sharp median process, but flat in a few specimens lacking this process, being equally wide at its anterior (near the level of sphenopalatine vacuities) and caudal portions (along the pterygoid processes) in specimens with intact pterygoids. Parapterygoid fossae shallow, at about the same level as the palate. Sphenopalatine vacuities reduced to narrow slits restricted to the presphenoid or completely ossified in a few specimens. Posterior opening of the alisphenoid canal and stapedial foramen large, sphenofrontal foramen and alisphenoid-squamosal groove conspicuous, conforming to the primitive carotid circulation pattern (Weksler 2006) or pattern 1 of Voss (1988). Alisphenoid strut absent, and buccinator-masticatory and accessory oval foramina confluent. Hamular process slender, delimiting a larger subsquamosal fenestra and smaller postglenoid foramen. Tegmen tympani present and connected to the posterior suspensory process of squamosal. Bullae globular, constituted by a large ectotympanic, which contributes to the wall of the carotid canal and restricts the exposed ventral surface of the periotic to a narrow lip. Mastoid completely ossified or with a narrow perforation on its posterodorsal limit. Mandible high and without conspicuous masseteric crests (Fig. 11). Capsular process of lower incisive alveolus reduced to a slight elevation. Sigmoid notch wide, shallow and symmetrically incised; coronoid process reduced, not projecting beyond the dorsal limit of the condyloid process; coronoid and condyloid process connected by an elevated bony ridge that has about the same height as the coronoid process. Angular process reduced and not projected posteriorly beyond the limit of the condyloid process. Incisors ungrooved, with yellow enamel bands. Upper incisors strongly opisthodont. Molars pentalophodont. Upper molar rows parallel sided, long (LM = 4.53–5.2 mm) and wide (BM 1 = 1.34–1.64 mm) (Table 4). M 1 with anterocone very asymmetrically divided by an anteromedian flexus, which penetrates the anterior margin of the procingulum at a point more lingually displaced in relation to the labial limit of the protoflexus, resulting in a much narrower anterolingual conule and a much wider anterolabial conule (Fig. 7 a). Anteroloph well developed and connected to the anterolabial conule in worn molars, forming an anterofossete which is confluent with the anteromedian flexus. Paraflexus and metaflexus deeply incised into the occlusal surface, penetrating beyond the medial limit of the protoflexus and hypoflexus. Median mure connected to the protocone. Mesoloph well developed, stemming from the median mure and reaching the labial cingulum. Paracone with a reduced paralophule contacting the mesoloph in older adults and delimiting a large medial enamel fossete and a shallow mesoflexus in older adults. Posteroflexus conspicuous, but frequently reduced to an enamel island in most adults or completely lost in older individuals. M 2 squared and with narrow anteroloph and shallow protoflexus. M 2 mesoloph as developed as in M 1, also contacting the paralophule and delimiting a large medial enamel fossete. Median mure similar to that of M 1. M 3 small and triangular, with deep paraflexus and narrow anteroloph present. Mesoflexus and metaflexus reduced to enamel islands in adult individuals. Mesoloph present, but fully coalesced to the paracone at the labial margin. Hypocone reduced and hypoflexus shallow. Metacone, posteroloph and posteroflexus not identifiable in adult specimens. Lower molar series longer and narrower than the upper series (length = 5.3–5.47 mm; width of m 1 = 1.24–1.36 mm). Procingulum of m 1 narrow, with anteroconid asymmetrically divided by a shallow anteromedian flexid (Fig. 7 d); anteromedian fossetid wide and fused to anteromedian flexid in younger individuals; anterolophid absent; protolophid well developed and diagonally projected to the labial margin, contacting the anterolabial conulid at its medial portion; protoflexid deeply incised into the occlusal surface; metaflexid subdivided into a shallow lingual fold and a small enamel island, which is separated from the protoflexid by the anterior murid; mesolophid well developed and projected lingually, isolated from the metaconid by a deep mesoflexid and connected to the entoconid by a lophulid; ectostylid present and well developed in most specimens, and in older adults resembling an ectolophid; posteroflexid deep and posterolophid wide; m 2 similar to m 1, with a variably present ectolophid; reduced anterolabial cingulum and shallow protoflexid as sole remnant structures of the procingulum; m 3 about the same size as m 2; anterolabial cingulum and protoflexid absent; mesolophid barely distinguishable in adult molars; entoflexid and posteroflexid as enamel islands; hypoflexid deep; ectostylid reduced and ectolophid usually absent. Variation in Delomys altimontanus . Nine cytb haplotypes were identified among the 15 sequenced D. altimontanus specimens from Caparaó Mt. (locality 6) and from two high-elevation localities in Itatiaia (localities 18 and 21) (Fig. 12 a). The genealogical relationships portrayed by the statistical parsimony network do not support the haplotypes from Itatiaia and Caparaó as two exclusive genetic groups, in spite of the large distributional gap (ca. 300 km) between these two populations (Fig. 12 b). Haplotype 8 from Caparaó, for instance, is connected to haplotype 3 from Itatiaia by three mutational steps rather than to the other two most frequent haplotypes from Caparaó (haplotypes 1 and 7), from which it differs by eight mutational steps. The six Itatiaia haplotypes are positioned in the center of the network, differing from one another by just a few mutational steps (one to six). The most frequent of these haplotypes (haplotype 4) is shared between two adjacent collecting sites (localities 18 and 21, Fig. 12 b). The quantitative results of the AMOVA analysis show that most variation among haplotypes (69.3 %) is due to differentiation within populations or within collecting localities rather than among the two disjunct populations (30.7 %). Fixation indexes are also not statistically different from zero (Φ SC= 0.4861, p= 0.1212; Φ CT= 0.3069, p= 0.3118), suggesting a low level of geographic differentiation in D. altimontanus. Despite the low level of geographic structure suggested by molecular variation in D. altimontanus, a Canonical Variates analysis of craniometric characters revealed that the Caparaó population differs from Itatiaia by having a somewhat longer rostrum (LD) and wider interorbit (LIB), whereas the Itatiaia population has slightly wider molars (BM 1) and longer incisive foramina (LIF) (Fig. 12 c). All specimens from Caparaó could be correctly reclassified into their respective group, while 91.7 % of the specimens from Itatiaia were correctly reallocated by minimum Mahalanobis distances. However, a bivariate plot combining the incisive foramina and diastema lengths shows that the segregation between the two samples is much more subtle, with at least four specimens completely overlapped (Fig. 12 d). The dorsal pelage of Caparaó specimens also tend to be more orangish along the flanks than in Itatiaia specimens. Nevertheless, the Caparaó sample we examined has a larger number of old adult individuals. Given that rostral length and brightness of the lateral pelage are both correlated with age, the age bias could not be discarded as a putative cause of these differences between samples. Natural history. Little is known about life history aspects of D. altimontanus, most observations being based on habitat descriptions by collectors. At the Caparaó mountain range, Bonvicino et al. (1997) described the variation in small mammal species composition and abundance along the elevational gradient of 1000 to 2700 m. Delomys altimontanus (therein identified as D. collinus) was trapped at elevations higher than 1800 m, where it was frequently associated with humid montane forests and shrubs, and corresponded to 14.3 to 27.1 % of the small mammals captured at these high altitude habitats. No captures were recorded at lower altitudinal zones (1400 to 1000 m), where submontane secondary forests predominated. Bonvicino et al. (1997) did not report any other species of Delomys at the Caparaó mountain range. Nevertheless, nearby records at lower elevations throughout Espírito Santo (localities 5 and 7) and Minas Gerais states (localities 9 and 10) suggest that D. sublineatus may occur sympatrically with D. altimontanus in the Caparaó region, but probably occupying the lower altitudinal zones and exhibiting limited syntopy with its mountaintop congener. At the Itatiaia mountain range, Delomys altimontanus appears to be the only Delomys species recorded above 2100 m, on the altiplano dominated by campos de altitude vegetation (locality 21, Campos do Itatiaia

Delomys dorsalis (Hensel 1872) Hesperomys dorsalis Hensel (1872): 42 Hesperomys dorsalis obscura Leche (1886): 696 Akodon dorsalis: Trouessart (1898): 537 (new name combination) Akodon dorsalis obscura: Trouessart (1898): 537 (new name combination) Akodon dorsalis lechei Trouessart (1904): 434 Hesperomys (Oryzomys) dorsalis: Miranda-Ribeiro (1905): 187 (new name combination) Thomasomys dorsalis: Thomas (1906): 443 (new name combination) Delomys dorsalis: Thomas (1917): 196 (new name combination) Delomys dorsalis collinus Thomas (1917): 197 Delomys dorsalis dorsalis: Gyldenstolpe (1932): 60 (new name combination) Delomys dorsalis lechei: Gyldenstolpe (1932): 61 (new name combination) Thomasomys dorsalis dorsalis: Ellerman (1941): 368 (new name combination) Thomasomys dorsalis collinus: Ellerman (1941): 369 (new name combination) Thomasomys dorsalis lechei: Ellerman (1941): 369 (new name combination) Thomasomys lechei: Moojen (1952): 59 Thomasomys collinus: Moojen (1952): 60 Delomys collinus: Avila-Pires (1960): 32 (new name combination) Emended diagnosis. A medium-sized species of the genus Delomys with soft and dense dorsal pelage, predominantly dark cinnamon-brown in color and without a bright yellow lateral line or patch; tail as long as head and body; skull with pronounced rostrum and elongated nasal tube, formed by most of premaxillary length and projected beyond the gnathic process; supraorbital region exhibiting the fronto-parietal (coronal) suture discontinuous with the fronto-squamosal suture, forming an area of dorsal contact between the squamosal and the frontal; mandible with wide, deep, and asymmetrically excavated sigmoid notch, robust coronoid process and wellpronounced angular process; karyotype with 2 n= 82 and FN= 80. Distribution. The samples recognized here as D. dorsalis are distributed from the southernmost limits of the Brazilian Atlantic forest to the northernmost limits of the Serra do Mar, at the center of the Rio de Janeiro state. The distribution of D. dorsalis extends westward to the Misiones province in Argentina, but few records are available in the interior parts of Paran�� and S��o Paulo states. Most collecting localities are situated along the coastal mountains covered by extensive humid montane and submontane forests, which in the Southern Highlands are frequently associated with the austral conifer Araucaria angustifolia. The submontane and montane forests in coastal Brazil occur at elevations of 30 to 1000 m between latitudes of 24 ��S and 32 ��S in the southernmost limit of the Brazilian Atlantic forest, but tend to occupy higher elevational intervals of 50 to 1500 m between the latitudes of 24 ��S and 14 ��S in Southeastern Brazil (Veloso et al. 1992). Likewise, the altitudinal distribution recorded for D. dorsalis in Southern Brazil varies from 57 m (locality 66) to 1700 m (locality 63), while in Southeastern Brazil, northern to the latitude of 24 ��S it varies from 650 (locality 44) to 1950 m (locality 27). Variation in Delomys dorsalis . As previously evidenced by the molecular phylogenetic analyses, D. dorsalis exhibits an extensive molecular variation in relation to both D. altimontanus and D. sublineatus. Sixty-five haplotypes were identified among the 78 sequenced individuals of D. dorsalis sampled from 18 collecting localities, and their relationships suggest the recognition of three geographically defined intraspecific clades concordant with the distribution of the Mantiqueira, Serra do Mar and Southern mountain ranges in coastal Brazil (Fig. 13 a). The quantitative results of the AMOVA analysis add further support to this spatial structure, indicating that a substantial component of the variation among haplotypes in D. dorsalis (80.9 %; �� CT= 0.8091, pr = 0.91, p = 0.025) suggest that the artifactual sampling gap of collecting localities cannot be ruled out as the main cause of the genetic discontinuity between northernmost and southernmost populations in the Southern clade (de Queiroz & Good 1997). Delomys dorsalis is also morphologically variable and, as previously mentioned, the number of mammary pairs does exhibit a discrete pattern of geographic variation within the species (Fig. 13 b). The adult females examined from the Mantiqueira and Serra do Mar clades (n = 35) exhibit six mammae, while those from the Southern clade exhibit eight mammae (n = 19, including the Argentinean sample from Misiones), corroborating the pattern of variation described by Thomas (1917) and Voss (1993). The geographic transition between the two mammary conditions occurs around 23 �� 50 ���S latitude, in the S��o Paulo state, and no population sampled in this region exhibits polymorphism of this trait (localities 36, 37 and 48). This transition is coincident with the latitudinal location of populations, but not fully congruent with the phylogenetic hierarchy within D. dorsalis, as the 6 -mammae and 8 -mammae lineages are not recovered as reciprocally monophyletic groups (Fig. 13 c). A parsimony optimization (accelerated transformation) of mammary variation onto the molecular phylogeny of the genus, assuming the 8 -mammae condition as primitive (Jansa & Weksler 2004; Weksler 2006), suggests two mammary number transformations along the evolutionary diversification of Delomys. The first would involve a loss of the pectoral pair in the ancestor of D. altimontanus and D. dorsalis, and the second would consist in a unique reacquisition of the pectoral pair (reversal) in the Southern clade of D. dorsalis. Nevertheless, since the close relationship between D. altimontanus and D. dorsalis has weak statistical support (Delomys are still uncertain and a better resolved phylogeny of the three species is needed for more conclusive character reconstructions. A CVA including representatives of the Mantiqueira, Serra do Mar and Southern clades of D. dorsalis, including topotypes of D. dorsalis and the holotype of D. d. collinus, was carried out to test whether the craniometric variation among these three clades was congruent with their molecular or mammae number variation patterns. The three clades are depicted as three broadly overlapping clusters segregating along both CV 1 and CV 2, which account, respectively, for 70.2 % and 29.8 % of the among-group variation (Fig. 14 a). The Mantiqueira clade diverges from Serra do Mar and Southern clades along CV 2 by exhibiting longer molar toothrows (LM) and larger zygomatic plates (BZP) (Fig. 14 b). Serra do Mar and Southern clades diverge along CV 1 mostly due to variations in the interobital breadth (LIB), which is relatively wider in the Serra do Mar clade. Unlike the among-species CVA (Fig. 8) or the molecular phylogenies, however, craniometric discrimination among the D. dorsalis clades is less clear cut, with discriminant functions correctly allocating respectively 84.1 %, 90.7 % and 77.6 % of the Mantiqueira, Serra do Mar and Southern clades representatives. Indeed, bivariate plots combining the most discriminant craniometric characters confirm a large overlap between Mantiqueira and Serra do Mar clades and between Mantiqueira and Southern clades (Figs. 14 c���d). Therefore, craniometric variation among the three intraspecific lineages of D. dorsalis is too subtle to identify exclusive clusters in multivariate or bivariate analyses. Despite the craniometric continuum among the three intraspecific clades, samples without genetic data could be allocated to one of the three geographic groups with moderate confidence levels. The D. dorsalis topotypes from Taquara (locality 66) were allocated to the Southern clade in 81 % of the bootstrap iterations, while the holotype of D. dorsalis collinus and specimens from adjacent localities 20, 30 and 33 (Fig. 1) in Minas Gerais and S��o Paulo states were allocated to the Mantiqueira clade in all bootstrap iterations. Finally, a female of D. dorsalis with 8 mammae from a geographically distant locality in Argentina (locality 62) could also be confidently allocated to the Southern clade in all bootstrap iterations. Thomas (1917) remarked on the length of upper molars as a distinctive trait for D. d. collinus (measured 5.0 mm by Thomas and 4.98 mm by us) in relation to Southern samples of D. dorsalis (measured 4.5���4.7 mm by Thomas). However, as shown in the bivariate plot (Fig. 14 d), the Southern samples of D. dorsalis display a wider variation than that portrayed by Thomas (1917), weakening the value of dental measurements to diagnose D. d. collinus. In general, the craniometric variation among the three clades is subtle and no exclusive clusters representing the three D. dorsalis clades could be identified in the multivariate and bivariate combinations of characters (Fig. 14). In the light of the current molecular and morphological evidence, applying the name D. dorsalis collinus to the 6 -mammate specimens from Mantiqueira and Serra do Mar, as originally envisioned by Thomas (1917) and Voss (1993), would render this subspecies paraphyletic or dyphyletic respective to 8 -mammate D. dorsalis dorsalis. An alternative would be to restrict D. dorsalis collinus to the Mantiqueira clade and D. dorsalis dorsalis to the Southern clade, describing the Serra do Mar clade as a distinct subspecies. Although more congruent with the number of lineages in D. dorsalis, this last option does not seem practical, since the recognition of subspecies would be fully dependent on molecular data in the absence of diagnostic morphological characters between the Serra do Mar and Mantiqueira populations. Voss (1993) reported a high frequency of specimens from Borac��ia and Casa Grande, in S��o Paulo state, with white tipped tails. This condition was not found in other samples from Serra do Mar examined by us, such as those from Teres��polis or Parati, in the Rio de Janeiro state, and may rather be a locally polymorphic character. The Serra do Mar clade is also polymorphic for tail color pattern, with a higher frequency (57 %) of weakly bicolored tails in samples from Alto da Serra, Borac��ia and Casa Grande, while other samples of this clade exhibit higher frequencies (> 60 %) of strongly bicolored tails. Given the current uncertainty in the morphological discrimination among the three clades of D. dorsalis, we opted not to formally recognize subspecies based on them, and regard D. dorsalis collinus as a junior synonym of D. dorsalis., Published as part of Gon��alves, Pablo Rodrigues & Oliveira, Jo��o Alves De, 2014, An integrative appraisal of the diversification in the Atlantic forest genus Delomys (Rodentia: Cricetidae: Sigmodontinae) with the description of a new species, pp. 1-38 in Zootaxa 3760 (1) on pages 26-29, DOI: 10.11646/zootaxa.3760.1.1, http://zenodo.org/record/285479, {"references":["Hensel, R. (1872) Beitrage zur Kenntniss der Saugethiere Sud-Brasiliens. Koniglichen Akadademie der Wissenschaften, Berlin, 130 pp.","Leche, W. (1886) Ueber einige sudbrasilianische Hesperomys - Arten. Zoologische Jahrbucher, 1, 687 - 702.","Trouessart, E. - L. (1898) Catalogus mammalium tam viventium quam fossilium. R. Friedlander & Sohn, Berlin, 664 pp.","Trouessart, E. - L. (1904) Catalogus mammalium tam viventium quam fossilium, quinquennale supplementum. R. Friedlander & Sohn, Berlin, 929 pp.","Miranda-Ribeiro, A. (1905) Vertebrados do Itatiaya (Peixes, Serpentes, Saurios, Aves e Mammiferos). Archivos do Museu Nacional, 13, 165 - 190.","Thomas, O. (1906) Notes on South American rodents. III. A new Oecomys and two new species of Holochilus. Annals and Magazine of Natural History, 7 (18), 442 - 448.","Thomas, O. (1917) On the arrangement of South American rats allied to Oryzomys and Rhipidomys. Annals and Magazine of Natural History, 8 (20), 192 - 198.","Gyldenstolpe, N. (1932) A manual of neotropical sigmodont rodents. Kungliga Svenska Ventenskapsakad Handlingar, 3, 1 - 164.","Ellerman, J. R. (1941) The families and genera of living rodents with a list of named forms by R. W. Hayman and G. W. C. Holt (1758 - 1936). Vol. 2. Family Muridae. British Museum (Natural History), London, 690 pp.","Moojen, J. (1952) Os Roedores do Brasil. Instituto Nacional do Livro, Rio de Janeiro, 214 pp.","Avila-Pires, F. D. (1960) Roedores colecionados na regiao de Lagoa Santa, Minas Gerais, Brasil. Arquivos do Museu Nacional, 50, 25 - 45.","Veloso, H. P., Filho, L. C. O., Vaz, A. M. S. F., Lima, M. P. M., Marquete, R. & Brazao, J. E. M. (1992) Manual tecnico da vegetacao brasileira. Fundacao Instituto Brasileiro de Geografia e Estatistica, Rio de Janeiro, 92 pp.","de Queiroz, K. & Good, D. A. (1997) Phenetic clustering in biology: a critique. The Quarterly Review of Biology, 72, 1 - 30.","Voss, R. S. (1993) A revision of the Brazilian Muroid Rodent genus Delomys with remarks on \" Thomasomyine \" characters. American Museum Novitates, 3073, 1 - 44.","Jansa, S. A. & Weksler, M. (2004) Phylogeny of muroid rodents: relationships within and among major lineages as determined by IRBP gene sequences. Molecular Phylogenetics and Evolution, 31, 256 - 276. http: // dx. doi. org / 10.1016 / j. ympev. 2003.07.002"]}

Delomys dorsalis (Hensel 1872) Hesperomys dorsalis Hensel (1872): 42 Hesperomys dorsalis obscura Leche (1886): 696 Akodon dorsalis: Trouessart (1898): 537 (new name combination) Akodon dorsalis obscura: Trouessart (1898): 537 (new name combination) Akodon dorsalis lechei Trouessart (1904): 434 Hesperomys (Oryzomys) dorsalis: Miranda-Ribeiro (1905): 187 (new name combination) Thomasomys dorsalis: Thomas (1906): 443 (new name combination) Delomys dorsalis: Thomas (1917): 196 (new name combination) Delomys dorsalis collinus Thomas (1917): 197 Delomys dorsalis dorsalis: Gyldenstolpe (1932): 60 (new name combination) Delomys dorsalis lechei: Gyldenstolpe (1932): 61 (new name combination) Thomasomys dorsalis dorsalis: Ellerman (1941): 368 (new name combination) Thomasomys dorsalis collinus: Ellerman (1941): 369 (new name combination) Thomasomys dorsalis lechei: Ellerman (1941): 369 (new name combination) Thomasomys lechei: Moojen (1952): 59 Thomasomys collinus: Moojen (1952): 60 Delomys collinus: Avila-Pires (1960): 32 (new name combination) Emended diagnosis. A medium-sized species of the genus Delomys with soft and dense dorsal pelage, predominantly dark cinnamon-brown in color and without a bright yellow lateral line or patch; tail as long as head and body; skull with pronounced rostrum and elongated nasal tube, formed by most of premaxillary length and projected beyond the gnathic process; supraorbital region exhibiting the fronto-parietal (coronal) suture discontinuous with the fronto-squamosal suture, forming an area of dorsal contact between the squamosal and the frontal; mandible with wide, deep, and asymmetrically excavated sigmoid notch, robust coronoid process and wellpronounced angular process; karyotype with 2 n= 82 and FN= 80. Distribution. The samples recognized here as D. dorsalis are distributed from the southernmost limits of the Brazilian Atlantic forest to the northernmost limits of the Serra do Mar, at the center of the Rio de Janeiro state. The distribution of D. dorsalis extends westward to the Misiones province in Argentina, but few records are available in the interior parts of Paraná and São Paulo states. Most collecting localities are situated along the coastal mountains covered by extensive humid montane and submontane forests, which in the Southern Highlands are frequently associated with the austral conifer Araucaria angustifolia. The submontane and montane forests in coastal Brazil occur at elevations of 30 to 1000 m between latitudes of 24 °S and 32 °S in the southernmost limit of the Brazilian Atlantic forest, but tend to occupy higher elevational intervals of 50 to 1500 m between the latitudes of 24 °S and 14 °S in Southeastern Brazil (Veloso et al. 1992). Likewise, the altitudinal distribution recorded for D. dorsalis in Southern Brazil varies from 57 m (locality 66) to 1700 m (locality 63), while in Southeastern Brazil, northern to the latitude of 24 °S it varies from 650 (locality 44) to 1950 m (locality 27). Variation in Delomys dorsalis . As previously evidenced by the molecular phylogenetic analyses, D. dorsalis exhibits an extensive molecular variation in relation to both D. altimontanus and D. sublineatus. Sixty-five haplotypes were identified among the 78 sequenced individuals of D. dorsalis sampled from 18 collecting localities, and their relationships suggest the recognition of three geographically defined intraspecific clades concordant with the distribution of the Mantiqueira, Serra do Mar and Southern mountain ranges in coastal Brazil (Fig. 13 a). The quantitative results of the AMOVA analysis add further support to this spatial structure, indicating that a substantial component of the variation among haplotypes in D. dorsalis (80.9 %; Φ CT= 0.8091, p The molecular diversity in the Mantiqueira and Serra do Mar clades is relatively reduced, as haplotypes within these regions average 0.45 % and 0.64 % pairwise genetic distance, respectively. The Southern clade, on the other hand, exhibits larger polymorphism, with haplotypes averaging 0.91 % of pairwise genetic distance. The larger intraclade genetic distance in the Southern group is due to comparisons between haplotypes from the northernmost (states of São Paulo and Paraná) and southernmost localities (states of Santa Catarina and Rio Grande do Sul), which diverge by 1.47 % pairwise genetic distance in average. However, the positive and significant correlations between genetic and geographic distances of populations assessed by a Mantel test (r = 0.91, p = 0.025) suggest that the artifactual sampling gap of collecting localities cannot be ruled out as the main cause of the genetic discontinuity between northernmost and southernmost populations in the Southern clade (de Queiroz & Good 1997). Delomys dorsalis is also morphologically variable and, as previously mentioned, the number of mammary pairs does exhibit a discrete pattern of geographic variation within the species (Fig. 13 b). The adult females examined from the Mantiqueira and Serra do Mar clades (n = 35) exhibit six mammae, while those from the Southern clade exhibit eight mammae (n = 19, including the Argentinean sample from Misiones), corroborating the pattern of variation described by Thomas (1917) and Voss (1993). The geographic transition between the two mammary conditions occurs around 23 ° 50 ’S latitude, in the São Paulo state, and no population sampled in this region exhibits polymorphism of this trait (localities 36, 37 and 48). This transition is coincident with the latitudinal location of populations, but not fully congruent with the phylogenetic hierarchy within D. dorsalis, as the 6 -mammae and 8 -mammae lineages are not recovered as reciprocally monophyletic groups (Fig. 13 c). A parsimony optimization (accelerated transformation) of mammary variation onto the molecular phylogeny of the genus, assuming the 8 -mammae condition as primitive (Jansa & Weksler 2004; Weksler 2006), suggests two mammary number transformations along the evolutionary diversification of Delomys. The first would involve a loss of the pectoral pair in the ancestor of D. altimontanus and D. dorsalis, and the second would consist in a unique reacquisition of the pectoral pair (reversal) in the Southern clade of D. dorsalis. Nevertheless, since the close relationship between D. altimontanus and D. dorsalis has weak statistical support (Delomys are still uncertain and a better resolved phylogeny of the three species is needed for more conclusive character reconstructions. A CVA including representatives of the Mantiqueira, Serra do Mar and Southern clades of D. dorsalis, including topotypes of D. dorsalis and the holotype of D. d. collinus, was carried out to test whether the craniometric variation among these three clades was congruent with their molecular or mammae number variation patterns. The three clades are depicted as three broadly overlapping clusters segregating along both CV 1 and CV 2, which account, respectively, for 70.2 % and 29.8 % of the among-group variation (Fig. 14 a). The Mantiqueira clade diverges from Serra do Mar and Southern clades along CV 2 by exhibiting longer molar toothrows (LM) and larger zygomatic plates (BZP) (Fig. 14 b). Serra do Mar and Southern clades diverge along CV 1 mostly due to variations in the interobital breadth (LIB), which is relatively wider in the Serra do Mar clade. Unlike the among-species CVA (Fig. 8) or the molecular phylogenies, however, craniometric discrimination among the D. dorsalis clades is less clear cut, with discriminant functions correctly allocating respectively 84.1 %, 90.7 % and 77.6 % of the Mantiqueira, Serra do Mar and Southern clades representatives. Indeed, bivariate plots combining the most discriminant craniometric characters confirm a large overlap between Mantiqueira and Serra do Mar clades and between Mantiqueira and Southern clades (Figs. 14 c–d). Therefore, craniometric variation among the three intraspecific lineages of D. dorsalis is too subtle to identify exclusive clusters in multivariate or bivariate analyses. Despite the craniometric continuum among the three intraspecific clades, samples without genetic data could be allocated to one of the three geographic groups with moderate confidence levels. The D. dorsalis topotypes from Taquara (locality 66) were allocated to the Southern clade in 81 % of the bootstrap iterations, while the holotype of D. dorsalis collinus and specimens from adjacent localities 20, 30 and 33 (Fig. 1) in Minas Gerais and São Paulo states were allocated to the Mantiqueira clade in all bootstrap iterations. Finally, a female of D. dorsalis with 8 mammae from a geographically distant locality in Argentina (locality 62) could also be confidently allocated to the Southern clade in all bootstrap iterations. Thomas (1917) remarked on the length of upper molars as a distinctive trait for D. d. collinus (measured 5.0 mm by Thomas and 4.98 mm by us) in relation to Southern samples of D. dorsalis (measured 4.5–4.7 mm by Thomas). However, as shown in the bivariate plot (Fig. 14 d), the Southern samples of D. dorsalis display a wider variation than that portrayed by Thomas (1917), weakening the value of dental measurements to diagnose D. d. collinus. In general, the craniometric variation among the three clades is subtle and no exclusive clusters representing the three D. dorsalis clades could be identified in the multivariate and bivariate combinations of characters (Fig. 14). In the light of the current molecular and morphological evidence, applying the name D. dorsalis collinus to the 6 -mammate specimens from Mantiqueira and Serra do Mar, as originally envisioned by Thomas (1917) and Voss (1993), would render this subspecies paraphyletic or dyphyletic respective to 8 -mammate D. dorsalis dorsalis. An alternative would be to restrict D. dorsalis collinus to the Mantiqueira clade and D. dorsalis dorsalis to the Southern clade, describing the Serra do Mar clade as a distinct subspecies. Although more congruent with the number of lineages in D. dorsalis, this last option does not seem practical, since the recognition of subspecies would be fully dependent on molecular data in the absence of diagnostic morphological characters between the Serra do Mar and Mantiqueira populations. Voss (1993) reported a high frequency of specimens from Boracéia and Casa Grande, in São Paulo state, with white tipped tails. This condition was not found in other samples from Serra do Mar examined by us, such as those from Teresópolis or Parati, in the Rio de Janeiro state, and may rather be a locally polymorphic character. The Serra do Mar clade is also polymorphic for tail color pattern, with a higher frequency (57 %) of weakly bicolored tails in samples from Alto da Serra, Boracéia and Casa Grande, while other samples of this clade exhibit higher frequencies (> 60 %) of strongly bicolored tails. Given the current uncertainty in the morphological discrimination among the three clades of D. dorsalis, we opted not to formally recognize subspecies based on them, and regard D. dorsalis collinus as a junior synonym of D. dorsalis.

Delomys altimontanus, new species Delomys collinus: Bonvicino & Geise 1995 (not collinus Thomas 1917) Delomys dorsalis: Hershkovitz 1998 (not dorsalis Hensel 1972) Delomys sublineatus: Hershkovitz 1998 (not sublineatus Thomas 1903) Type material. The holotype, MN 69746, is an adult male collected by Pablo R. Gon��alves, Jo��o A. Oliveira, Cibele R. Bonvicino and Maria Ol��mpia G. Lopes on 28 November 2004 (field number JAO 1558). The specimen was collected in a Sherman��� trap placed in a montane shrub dominated by bamboo at the margin of the Campo Belo stream, close to the Abrigo Rebou��as. The specimen consists of a skin, skull and postcranial skeleton accompanied by a liver tissue sample preserved in ethanol and femoral medullar cells preserved in methanol/acetic acid solution. We designate as paratypes seven specimens collected in the localities of Abrigo Rebou��as (MN 69712, male) at Itatiaia -, Rio de Janeiro state, and Brejo da Lapa (MN 60573 -60576, 60584, 60585), municipality of Itamonte, Minas Gerais state. Type locality. Campos do Itatiaia, (22 �� 23 ��� 26 ���S, 44 �� 40 ��� 14 ���W, 2450m altitude), near Abrigo Rebou��as, Parque Nacional do Itatiaia, municipality of Itatiaia, Rio de Janeiro state, Brazil (locality 21, Figs. 1 and 12 a). Etymology. The specific epithet altimontanus refers to the restricted altitudinal distribution of the species, exclusively inhabiting the forested altiplano of the Mantiqueira mountain range in southeastern Brazil (from the Latin altus = high + montanus = mountain inhabitant). Distribution. This species exhibits a disjunct distribution with reported populations apparently restricted to the highest altitudinal forested zones of 1800 to 2500 m in the Itatiaia and Capara�� mountain ranges, which are two different offshoots of the Mantiqueira mountain complex. Populations of Delomys that have been sampled in the intervening mountain chains that are part of the coastal Serra do Mar mountain complex, such as the Serra da Bocaina, Serra dos ��rg��os and Serra do Desengano (in Rio de Janeiro state), or even in lower mountains of the Mantiqueira complex (Serra do Brigadeiro in Minas Gerais state), have been identified as either D. dorsalis or D. sublineatus (Delciellos et al. 2012; Modesto et al. 2008; Moreira et al. 2009; Olifiers et al. 2007). These facts suggest that the current disjunct distribution of Delomys altimontanus sp. nov. is a relict of a formerly wider distribution rather than a sampling artifact across Southeastern Brazil. It is probable that additional populations of D. altimontanus occur throughout the Mantiqueira range, especially in the mountains adjacent to Itatiaia that extend to the southwestern into S��o Paulo state (Campos do Jord��o, Piquete) and Minas Gerais (e.g., Itamonte, Delfim Moreira, Passa Quatro). Nevertheless, available samples from these localities do not show the diagnostic morphological or genetic characters of D. altimontanus, rather representing D. dorsalis populations. Karyotype. The karyotype of Delomys altimontanus (Fig. 9) exhibits 2 n = 82 and FN= 86, with an autosomal complement constituted by 3 pairs of biarmed chromosomes, 27 pairs of acrocentrics, a large-sized submetacentric X chromosome and a small metacentric Y chromosome, as previously described by Bonvicino & Geise (1995). Delomys altimontanus diverges from D. sublineatus (2 n= 72, FN= 90) in both diploid and fundamental numbers, but shares the same diploid number with D. dorsalis (2 n= 82), from which it can be distinguished by the morphology of three small-sized biarmed pairs of autosomes. This karyological difference between Delomys altimontanus and D. dorsalis probably evolved through pericentric inversions involving the smallest pairs of autosomes. Diagnosis. A medium-sized species of the genus Delomys with soft and long dorsal pelage, predominantly cinnamon-brown grizzled with yellow, but becoming brighter orange along the flanks; tail as long as head-andbody length and strongly bicolor throughout most of its length; skull with pronounced rostrum and elongated nasal tube projecting beyond the gnathic process; relatively longer and wider molar series than in other congeneric taxa; relatively narrow interorbit; supraorbital region exhibiting the fronto-parietal (coronal) suture collinear with the fronto-squamosal suture, without an area of dorsal contact between squamosal and frontal; incisive foramina with straight margins along the maxillary; mesopterygoid fossa equally wide at its anterior and posterior portions; mandible with wide, shallow and symmetrically excavated sigmoid notch, delicate coronoid process and reduced angular process; karyotype with 2 n= 82 and FN= 86. Description. Body pelage soft, dense and long, with guard hairs along the cervical region of the dorsum varying in length from 15 to 20 mm. General dorsal color is cinnamon-brown in adults, brighter and orangish along the laterals and gradually darker towards the mid-dorsum, generally forming a ill-defined median stripe in most specimens, which extends from the nape to the base of tail (Fig. 10). In old adults the sides of body are more rusty colored due to the presence of bright orange bands on hairs, while young specimens generally display a duller and grayer dorsal and lateral color with few traces of yellowish tone. Ventral pelage predominantly white, covered by whitish hairs with wide dark-gray bases frequently showing through. Head similar in coloration to the mid-dorsum, becoming brighter at the cheeks. Neck and chin region covered by smaller bicolored hairs, similar in coloration to those of the ventral region. Eyes large and surrounded by short dark hairs, forming a narrow eye-ring. Mystacial, superciliary, genal, submental, interramal and carpal vibrissae present. Mystacial vibrissae long, with the two longest reaching the distal tip of the pinnae when laid back. Pinnae large (Table 4) and sparsely covered with short hairs on its internal surface, but more densely furred on its dorsal surface. Cheiridia dorsally covered by short whitish hairs, most of them with dark bases, specially at the proximal metacarpal and metatarsal regions, giving a general soiled or gray aspect to the dorsal surfaces of manus and pes. Hindfoot long and narrow. Ungual tufts long and conspicuous, completely enclosing the claws on digits I���IV, but reduced or vestigial on digit V. Middle digits (II���IV) are longer than the outer digits (I and V), with digit III slightly longer than digits II and IV. Digit I is longer than digit V, with its claw extending to the middle of the first phalange of digit II, while the claw of digit V reaches the first interphalangeal joint of digit IV. Plantar surface naked over the heel and much of the metatarsal region, being more squamate over the digits surface. Six fleshy plantar pads present (hypothenar, thenar and four interdigital pads). Tail slightly longer to, or as long as, the head and body length (Table 4), sparsely covered by short hairs, and displaying a bicolor pattern throughout more than half of its length. The tail color is predominantly dark brown throughout its entire dorsum, but markedly whitish to buffy in the venter, throughout its first two proximal thirds, gradually intergrading to dark-brown towards the distal third. The brighter ventral color of the tail is provided by entirely whitish short hairs, which in the base of the tail span two to three scales in length. Towards the tail dorsum and the distal third of the tail venter, hairs with wide dark brown basal bands become more common, providing darker tones. Six mammae present in lactating females, distributed in inguinal, abdominal and postaxial pairs (pectoral pair lacking), displaying the mammary formula of 0/ 2 / 2 / 2. Cranium large and wide (CIL = 31.4 ��� 27mm, BB = 12.73 ��� 11.7mm, Table 4), with a narrow and elongated rostrum, biconcave and narrow interorbit and globular braincase with smooth edges (Fig. 11). Nasals long (NL = 14.65 ��� 11.75mm) and narrow, extending posteriorly beyond the fronto-premaxillary suture. The nasals taper more abruptly at their anterior midlength and then more subtly before converging at the fronto-nasal suture. Lacrimals squared and relatively large, contacting both the frontal and maxillary bones. Interorbital region relatively narrow and biconcave, exhibiting the typical ���hourglass��� morphology (Voss 1993) with smooth edges and without supraorbital crested margins, even in older adults. Fronto-nasal suture slightly depressed, with frontal sinuses dorsally prominent. Fronto-parietal (=coronal) suture U-shaped, generally open angled in most specimens, but also sharply angled in some older adults, especially towards its lateral limits. Fronto-parietal and fronto-squamosal sutures collinear, as both the parietal and squamosal bones contact the frontal nearly at the same level along the postorbital wall, leaving no area for a contact between the squamosal and the dorsal surface of the frontal. Parietals wide and slightly expanded onto the lateral surface of the braincase near the squamosal root of the zygomatic arch. Interparietal moderately wide and semicircular, not contacting the squamosal laterally. Zygomatic plate broad and projected anteriorly to the base of the lacrimal capsule, forming a conspicuous zygomatic notch; its anterodorsal margin smoothly rounded. Posterior margin of the zygomatic plate situated anterior to the alveolus of M 1. Zygomatic arch laterally expanded, formed by a large jugal and non-overlapping maxillary and squamosal branches. Postorbital wall with small ridges near the squamosal root of the zygomatic arch, and a conspicuous buccinator-masticatory trough. Incisive foramina wide, with an inflated and expanded palatine process and reduced maxillary septum; lateral outlines of the incisive foramina are straight lined along their maxillary portions, being sharply bent only at their caudal ends, where they terminate anterior to the M 1 alveolus. Palate surface flat, without expressive lateral troughs or posterolateral pits. Bony palate short, with the mesopterygoid fossa extending anteriorly between the molar rows; anterior margin of the mesopterygoid fossa biconcave in most specimens due to the presence of a sharp median process, but flat in a few specimens lacking this process, being equally wide at its anterior (near the level of sphenopalatine vacuities) and caudal portions (along the pterygoid processes) in specimens with intact pterygoids. Parapterygoid fossae shallow, at about the same level as the palate. Sphenopalatine vacuities reduced to narrow slits restricted to the presphenoid or completely ossified in a few specimens. Posterior opening of the alisphenoid canal and stapedial foramen large, sphenofrontal foramen and alisphenoid-squamosal groove conspicuous, conforming to the primitive carotid circulation pattern (Weksler 2006) or pattern 1 of Voss (1988). Alisphenoid strut absent, and buccinator-masticatory and accessory oval foramina confluent. Hamular process slender, delimiting a larger subsquamosal fenestra and smaller postglenoid foramen. Tegmen tympani present and connected to the posterior suspensory process of squamosal. Bullae globular, constituted by a large ectotympanic, which contributes to the wall of the carotid canal and restricts the exposed ventral surface of the periotic to a narrow lip. Mastoid completely ossified or with a narrow perforation on its posterodorsal limit. Mandible high and without conspicuous masseteric crests (Fig. 11). Capsular process of lower incisive alveolus reduced to a slight elevation. Sigmoid notch wide, shallow and symmetrically incised; coronoid process reduced, not projecting beyond the dorsal limit of the condyloid process; coronoid and condyloid process connected by an elevated bony ridge that has about the same height as the coronoid process. Angular process reduced and not projected posteriorly beyond the limit of the condyloid process. Incisors ungrooved, with yellow enamel bands. Upper incisors strongly opisthodont. Molars pentalophodont. Upper molar rows parallel sided, long (LM = 4.53���5.2 mm) and wide (BM 1 = 1.34���1.64 mm) (Table 4). M 1 with anterocone very asymmetrically divided by an anteromedian flexus, which penetrates the anterior margin of the procingulum at a point more lingually displaced in relation to the labial limit of the protoflexus, resulting in a much narrower anterolingual conule and a much wider anterolabial conule (Fig. 7 a). Anteroloph well developed and connected to the anterolabial conule in worn molars, forming an anterofossete which is confluent with the anteromedian flexus. Paraflexus and metaflexus deeply incised into the occlusal surface, penetrating beyond the medial limit of the protoflexus and hypoflexus. Median mure connected to the protocone. Mesoloph well developed, stemming from the median mure and reaching the labial cingulum. Paracone with a reduced paralophule contacting the mesoloph in older adults and delimiting a large medial enamel fossete and a shallow mesoflexus in older adults. Posteroflexus conspicuous, but frequently reduced to an enamel island in most adults or completely lost in older individuals. M 2 squared and with narrow anteroloph and shallow protoflexus. M 2 mesoloph as developed as in M 1, also contacting the paralophule and delimiting a large medial enamel fossete. Median mure similar to that of M 1. M 3 small and triangular, with deep paraflexus and narrow anteroloph present. Mesoflexus and metaflexus reduced to enamel islands in adult individuals. Mesoloph present, but fully coalesced to the paracone at the labial margin. Hypocone reduced and hypoflexus shallow. Metacone, posteroloph and posteroflexus not identifiable in adult specimens. Lower molar series longer and narrower than the upper series (length = 5.3���5.47 mm; width of m 1 = 1.24���1.36 mm). Procingulum of m 1 narrow, with anteroconid asymmetrically divided by a shallow anteromedian flexid (Fig. 7 d); anteromedian fossetid wide and fused to anteromedian flexid in younger individuals; anterolophid absent; protolophid well developed and diagonally projected to the labial margin, contacting the anterolabial conulid at its medial portion; protoflexid deeply incised into the occlusal surface; metaflexid subdivided into a shallow lingual fold and a small enamel island, which is separated from the protoflexid by the anterior murid; mesolophid well developed and projected lingually, isolated from the metaconid by a deep mesoflexid and connected to the entoconid by a lophulid; ectostylid present and well developed in most specimens, and in older adults resembling an ectolophid; posteroflexid deep and posterolophid wide; m 2 similar to m 1, with a variably present ectolophid; reduced anterolabial cingulum and shallow protoflexid as sole remnant structures of the procingulum; m 3 about the same size as m 2; anterolabial cingulum and protoflexid absent; mesolophid barely distinguishable in adult molars; entoflexid and posteroflexid as enamel islands; hypoflexid deep; ectostylid reduced and ectolophid usually absent. Variation in Delomys altimontanus . Nine cytb haplotypes were identified among the 15 sequenced D. altimontanus specimens from Capara�� Mt. (locality 6) and from two high-elevation localities in Itatiaia (localities 18 and 21) (Fig. 12 a). The genealogical relationships portrayed by the statistical parsimony network do not support the haplotypes from Itatiaia and Capara�� as two exclusive genetic groups, in spite of the large distributional gap (ca. 300 km) between these two populations (Fig. 12 b). Haplotype 8 from Capara��, for instance, is connected to haplotype 3 from Itatiaia by three mutational steps rather than to the other two most frequent haplotypes from Capara�� (haplotypes 1 and 7), from which it differs by eight mutational steps. The six Itatiaia haplotypes are positioned in the center of the network, differing from one another by just a few mutational steps (one to six). The most frequent of these haplotypes (haplotype 4) is shared between two adjacent collecting sites (localities 18 and 21, Fig. 12 b). The quantitative results of the AMOVA analysis show that most variation among haplotypes (69.3 %) is due to differentiation within populations or within collecting localities rather than among the two disjunct populations (30.7 %). Fixation indexes are also not statistically different from zero (�� SC= 0.4861, p= 0.1212; �� CT= 0.3069, p= 0.3118), suggesting a low level of geographic differentiation in D. altimontanus. Despite the low level of geographic structure suggested by molecular variation in D. altimontanus, a Canonical Variates analysis of craniometric characters revealed that the Capara�� population differs from Itatiaia by having a somewhat longer rostrum (LD) and wider interorbit (LIB), whereas the Itatiaia population has slightly wider molars (BM 1) and longer incisive foramina (LIF) (Fig. 12 c). All specimens from Capara�� could be correctly reclassified into their respective group, while 91.7 % of the specimens from Itatiaia were correctly reallocated by minimum Mahalanobis distances. However, a bivariate plot combining the incisive foramina and diastema lengths shows that the segregation between the two samples is much more subtle, with at least four specimens completely overlapped (Fig. 12 d). The dorsal pelage of Capara�� specimens also tend to be more orangish along the flanks than in Itatiaia specimens. Nevertheless, the Capara�� sample we examined has a larger number of old adult individuals. Given that rostral length and brightness of the lateral pelage are both correlated with age, the age bias could not be discarded as a putative cause of these differences between samples. Natural history. Little is known about life history aspects of D. altimontanus, most observations being based on habitat descriptions by collectors. At the Capara�� mountain range, Bonvicino et al. (1997) described the variation in small mammal species composition and abundance along the elevational gradient of 1000 to 2700 m. Delomys altimontanus (therein identified as D. collinus) was trapped at elevations higher than 1800 m, where it was frequently associated with humid montane forests and shrubs, and corresponded to 14.3 to 27.1 % of the small mammals captured at these high altitude habitats. No captures were recorded at lower altitudinal zones (1400 to 1000 m), where submontane secondary forests predominated. Bonvicino et al. (1997) did not report any other species of Delomys at the Capara�� mountain range. Nevertheless, nearby records at lower elevations throughout Esp��rito Santo (localities 5 and 7) and Minas Gerais states (localities 9 and 10) suggest that D. sublineatus may occur sympatrically with D. altimontanus in the Capara�� region, but probably occupying the lower altitudinal zones and exhibiting limited syntopy with its mountaintop congener. At the Itatiaia mountain range, Delomys altimontanus appears to be the only Delomys species recorded above 2100 m, on the altiplano dominated by campos de altitude vegetation (locality 21, Campos do Itatiaia, Published as part of Gon��alves, Pablo Rodrigues & Oliveira, Jo��o Alves De, 2014, An integrative appraisal of the diversification in the Atlantic forest genus Delomys (Rodentia: Cricetidae: Sigmodontinae) with the description of a new species, pp. 1-38 in Zootaxa 3760 (1) on pages 18-26, DOI: 10.11646/zootaxa.3760.1.1, http://zenodo.org/record/285479, {"references":["Bonvicino, C. R. & Geise, L. (1995) Taxonomic status of Delomys dorsalis collinus Thomas, 1917 (Rodentia, Cricetidae) and description of a new karyotype. Zeitschrift fur Saugetierkunde, 60, 124 - 127.","Thomas, O. (1917) On the arrangement of South American rats allied to Oryzomys and Rhipidomys. Annals and Magazine of Natural History, 8 (20), 192 - 198.","Hershkovitz, P. (1998) Report on some sigmodontine rodents collected in southeastern Brazil with descriptions of a new genus and six new species. Bonner Zoologische Beitrage, 47, 193 - 256.","Thomas, O. (1903) Notes on Neotropical mammals of the genera Felis, Hapale, Oryzomys, Akodon and Ctenomys, with descriptions of new species. Annals and Magazine of Natural History, 7 (12), 234 - 243. http: // dx. doi. org / 10.1080 / 00222930308678847","Delciellos, A. C., Novaes, R. L. M., Loguercio, M. F. C., Geise, L., Santori, R. F., Souza, R. F., Papi, B. S., Raices, D., Vieira, N. R., Felix, S., Detogne, N., Silva, C. C. S., Bergallo, H. G. & Rocha-Barbosa, O. (2012) Mammals of Serra da Bocaina National Park, state of Rio de Janeiro, southeastern Brazil. Checklist, 8, 675 - 692.","Modesto, T. C., Pessoa, F. S., Enrici, M. C., Attias, N., Costa, L. D. M., Albuquerque, H. G. & Bergallo, H. G. (2008) Mamiferos do Parque Estadual do Desengano, Rio de Janeiro, Brasil. Biota Neotropica, 8, 153 - 159.","Moreira, J. C., Manduca, E. G., Goncalves, P. R., Morais, M. M. J., Pereira, R. F., Lessa, G. & Dergam, J. A. (2009) Small mammals from Serra do Brigadeiro state park. Arquivos do Museu Nacional, 67, 103 - 118.","Olifiers, N., Eduardo, C., Grelle, V., Bonvicino, C. R., Geise, L., Pereira, L. G. & Cerqueira, R. (2007) Pequenos mamiferos naovoadores do Parque Nacional da Serra dos Orgaos. In: Cronemberger, C. & Viveiros de Castro, E. B. (Eds.), Ciencia e Conservacao na Serra dos Orgaos. IBAMA, Brasilia, pp. 188 - 192.","Voss, R. S. (1993) A revision of the Brazilian Muroid Rodent genus Delomys with remarks on \" Thomasomyine \" characters. American Museum Novitates, 3073, 1 - 44.","Voss, R. S. (1988) Systematics and ecology of ichthyomyine rodents (Muroidea), patterns of morphological evolution in a small adaptive radiation. Bulletin of the American Museum of Natural History, 188, 259 - 493.","Bonvicino, C. R., Langguth, A., Lindbergh, S. M. & Paula, A. C. (1997) An elevational gradient study of small mammals at Caparao National Park, South eastern Brazil. Mammalia, 61, 547 - 560.","Brade, A. C. (1956) A flora do Parque Nacional do Itatiaia. Boletim do Parque Nacional do Itatiaia, 5, 1 - 112."]}

We investigated patterns of spatial distribution and microhabitat selection of rodents in a patch (26 ha) of mixed ombrophilous forest (or Araucaria forest), dominated by the Araucaria 'pine' Araucaria angustifolia, in the National Park of Aparados da Serra, RS, in southern Brazil. We conducted monthly trapping sessions lasting 6 days (from June 2000 to June 2001) using a square grid of 121 trap stations, separated by 15 m (2.25 ha). We measured 10 microhabitat variables that could influence species distribution. These variables were related to the occurrence of mammals by using canonical correspondence analysis (CCA) and stepwise multiple regression. The distribution patterns of the three most common rodents differed significantly (X 2 = 38.6; P < 0.002), with Delomys dorsalis being more clumped than the other two species. Both CCA and multiple regression analysis showed a significant effect of microhabitat variables on species occurrence. The multiple regression parameters for Oligoryzomys nigripes were R 2 = 0.142, P < 0.05, for Akodon montensis were R 2 = 0.222, P < 0.01, and for D. dorsalis R 2 = 0.323, P< 0.001. Variables that significantly influenced species distribution were vegetation density at 1 m height and length of fallen logs for O. nigripes, canopy cover for A. montensis, and vegetation density at 2 m height, quantity of leaves of Araucaria trees (negative relationship), tree density (except Araucaria trees), and number of potential shelters, for D: dorsalis. The results indicated that D. dorsalis is the most habitat specialist among the rodent species and that there are no apparent competitive interactions.

Despite the advances in the techniques for researching arboreal small mammals, detailed ecological data, such as habitat use patterns, are practically nonexistent for many species. Using 150 live-traps installed on the ground, understory (1.0-5.0m) and canopy (>5.0m) we investigated patterns of arboreal and terrestrial space use by small mammals in an Araucaria Forest in southern Brazil (29°29′08″S; 50°12′26″W). We also measured 19 microhabitat variables that could potentially influence the abundance of such mammals on each trap station. The results indicated that Akodon montensis and A. serrensis were mainly terrestrial. Delomys dorsalis was also terrestrial, but it also used understory (17.24% of captures). Juliomys sp. and Gracilinanus microtarsus were the most arboreal small mammals recorded. A. montensis was associated with dense vegetation, while A. serrensis selected positively opened areas. Juliomys sp. and G. microtarsus were associated to microhabitat variables related to the access and movement within the canopy. Moreover, bromeliads on arboreal layer were an important factor for these two arboreal species. This is the first study to report microhabitat associations by Juliomys sp. and A. serrensis, and we demonstrated that vertical stratification and microhabitat use were both synergic mechanisms to determine habitat use by small mammals on the Araucaria Forest of southern Brazil. Apesar dos avanços nas técnicas para pesquisa de pequenos mamíferos arborícolas, dados ecológicos detalhados, tal como padrões de uso do habitat, são praticamente inexistentes para muitas espécies. Utilizando 150 armadilhas de captura viva instaladas no solo, sub-bosque (1,0-5,0m) e dossel (> 5,0m) nós investigamos padrões no uso do espaço arbóreo e terrestre por pequenos mamíferos em uma Floresta com Araucária no sul do Brasil (29°29′08″S; 50°12′26″W). Nós medimos 19 variáveis de micro-habitat que poderiam potencialmente influenciar a abundância de tais mamíferos em cada estação de captura. Os resultados indicaram que Akodon montensis e A. serrensis foram principalmente terrestres. Delomys dorsalis também foi terrestre, mas também utilizou o sub-bosque (17,24% das capturas). Juliomys sp. e Gracilinanus microtarsus foram os pequenos mamíferos mais arborícolas registrados. A. montensis esteve associado com vegetação densa, enquanto A. serrensisselecionou positivamente áreas abertas. Juliomys sp. e G. microtarsus estiveram associados a variáveis de micro-habitat relacionadas ao acesso e movimentação no dossel. Além disso, bromélias no estrato arbóreo foram um importante fator para estas duas espécies arborícolas. Este é o primeiro estudo a reportar associações de micro-habitat por Juliomyssp. e A. serrensis, e nós demonstramos que a estratificação vertical e o uso do micro-habitat são mecanismos sinergéticos em determinar o uso do habitat por pequenos mamíferos na Floresta com Araucária do sul do Brasil.

Alippistrongylus bicaudatus gen. et sp. n. (Nematoda: Heligmonellidae) is described from the striped Atlantic forest rat, Delomys dorsalis (Hensel) (Rodentia: Sigmodontinae), from the province of Misiones in Argentina. The new genus and species is characterised by a synlophe of 21 unequal ridges in both sexes without a gradient in size, with two ridges weakly sclerotised and oriented perpendicularly in the dorsal left quadrant; males with a highly dissymmetrical bursa with a hypertrophied right lobe, and females with a dorsal conical appendage just posterior to the vulva, conferring a two-tailed appearance to the female worms., Facultad de Ciencias Naturales y Museo

Here we describe the stomach contents of nine small mammal species (seven rodents and two didelphid marsupials) co-occurring in an old-growth Atlantic forest area. For four terrestrial rodents, we also compared the importance of arthropods in the diet and the selection of arthropod groups by comparing consumption with availability. Small mammals and arthropods were sampled in a 36-ha grid containing 25 sampling stations spaced every 150 m, and 47 stomach contents were analysed. While plant matter was the predominant item in the stomach contents of two rodents (Oligoryzomys nigripes and Rhipidomys mastacalis), four species presented arthropods as the main food item (the rodents Brucepattersonius soricinus and Oxymycterus dasytrichus, and the marsupials Monodelphis n. sp. and Marmosops incanus) and three consumed more plant matter than arthropods, but had significant amounts of both items (the rodents Delomys sublineatus, Euryoryzomys russatus and Thaptomys nigrita). Our results suggest that differences in ...

Cytogenetic analyses were performed in 39 specimens of Delomys trapped in six localities distributed along the Atlantic forest range of the genus. Only two karyotypic forms were found: 2n = 72, FN = 90 to the north and 2n = 82, FN = 80 to the south, with an overlapping area in Sao Paulo and Parana states. No hybrids were found and given the large difference in karyotype it is likely that any hybrids produced would be infertile. Based on the skin coloration and type localities of the species described it is suggested that the 2n = 72 taxon corresponds to Delomys sublineatus and the 2n = 82 form to D. dorsalis.

Recent taxonomic studies on Neotropical mammals have benefited from the use of genetic data to unravel and recognize species diversity in a number of genera, including the Atlantic forest endemic genus Delomys. However, the success of this approach depends on ability to link genetically identified lineages to species names based on voucher specimens that lack genetic data. Cytogenetic studies in the Atlantic forest endemic rodent genus Delomys have revealed two widespread karyotypes, 2n=72/FN=90 and 2n=82/FN=80, which have been respectively ascribed to Delomys sublineatus (Thomas, 1903) and D. dorsalis (Hensel, 1872). More recently, a third karyotype, 2n=82/FN=86, reported from specimens collected on two montaintops in southeastern Brazil, was interpreted as evidence for a third species, D. collinus Thomas, 1917. This nominal form had originally been described as a subspecies of D. dorsalis from Itatiaia, one of the mountain ranges where the third karyotype was later detected. The detection of two sympatric karyotypes at the type locality of D. collinus in the Itatiaia mountain range, Southeastern Brazil, prompted a reevaluation of the association of karyomorphs and species names. In this paper, we assessed the congruence of molecular (cytochrome b), cytogenetic and morphological characters, to diagnose the species in the genus, including data from recently collected series and type specimens. Our results indicate that the genetic and morphological patterns are largely congruent with the recognition of three species, each of which is karyotypically and morphologically diagnosable. Our morphological analyses of sympatric samples from Itatiaia refute the former association of the 2n=82/FN=86 karyotype with the holotype of D. dorsalis collinus (which is more similar to D. dorsalis with 2n=82/FN=80). Instead, we recognize and describe a new species for the 2n=82/FN=86 populations from the highest altitudinal zones of the Itatiaia and Caparao mountains. The geographical variation in D. dorsalis is also explored and the status of D. d. collinus is discussed in the light of the molecular and morphological evidence. Finally, we discuss biogeographic hypotheses concerning the disjunct distributions of D. dorsalis and the new species.

Delomys sublineatus (Thomas, 1903). Ann. Mag. Nat. Hist., ser. 7, 12:240. TYPE LOCALITY: Brazil, Espirito Santo, Engenheiro Reeve, 500 m. DISTRIBUTION: Atlantic coastal forest of SE Brazil, Espirito Santo to Paranâ., Published as part of Guy G. Musser & Michael D. Carleton, 1993, Order Rodentia - Family Muridae, pp. 501-755 in Mammal Species of the World (2 nd Edition), Washington and London :Smithsonian Institution Press on page 700, DOI: 10.5281/zenodo.7353098

Delomys Thomas, 1917. Ann. Mag. Nat. Hist., ser. 8, 20: 196. TYPE SPECIES: Hesperomys dorsalis Hensel, 1872. COMMENTS: Thomasomyine. Delomys has variously stood as a genus (Avila-Pires, 1960b; Gyldenstolpe, 1932; Tate, 1932/) or placed within Thomasomys, with or without formal subgeneric division (Ellerman, 1941; Moojen, 1952; Osgood, 1933d). As remarked by Osgood (1933d), Thomas in part created Delomys to taxonomically underscore the geographic disjunction between thomasomyines in SE Brazil and the diverse radiation of typical Thomasomys in the N Andes (e.g., see Reig, 1986). There are features that unite the forms of Delomys, but decision on its classificatory rank—and that of other SE Brazilian endemics like Wilfredomys, Rhagomys, and Phaenomys — must await broader-based phylogenetic inquiry involving Andean thomasomyines. Number of recognized species listed as four (Moojen, 1952), three (Reig, 1986), two (Ellerman, 1941; Gyldenstolpe, 1932), or one (Corbet and Hill, 1991; Cabrera, 1961), a situation which advises that future list-making would profit from critical specimen examination. Here we recognize two, D. dorsalis and D. sublineatus, following the karyotypic study of Zanchin et al. (1992b). Avila-Pires (1960b) associated Calomys plebejus Winge, 1887, as another form of Delomys; its status with regard to dorsalis and sublineatus warrents clarification., Published as part of Guy G. Musser & Michael D. Carleton, 1993, Order Rodentia - Family Muridae, pp. 501-755 in Mammal Species of the World (2 nd Edition), Washington and London :Smithsonian Institution Press on page 700, DOI: 10.5281/zenodo.7353098, {"references":["Avila-Pires, F. D., de. 1960 b. Um novo genero de roedor Sul-Americano. Boletim do Museu Nacional, Zoologia (Rio de Janeiro), 220: 1 - 6.","Gyldenstolpe, N. 1932. A manual of Neotropical sigmodont rodents. Kungliga Svenska Vetenskapsakademiens Handlingar, Tredje Serien, 11: 1 - 164.","Ellerman, J. R. 1941. The families and genera of living rodents. Vol. II. Family Muridae. British Museum (Natural History), London, 690 pp.","Moojen, J. 1952. Os roedores do Brasil. Biblioteca Cientifica Brasileira, ser. A, 2: 1 - 214.","Osgood, W. H. 1933 d. The generic position of Mus pyrrhorhinus Wied. Journal of Mammalogy, 14: 370 - 371.","Reig, O. A. 1986. Diversity patterns and differentiation of high Andean rodents. Pp. 404 - 440, in High altitude tropical biogeography (F. Vuilleumier and M. Monasterio, eds.). Oxford University Press, New York, 649 pp.","Corbet, G. B., and J. E. Hill. 1991. A world list of mammalian species. Third ed. British Museum (Natural History) Publications, London, 243 pp.","Zanchin, N. I. T., I. J. Sbalqueiro, A. Langguth, R. C. Bossle, E. C. Castro, L. F. B. Oliveira, and M. S. Mattevi. 1992 b. Karyotype and species diversity of the genus Delomys (Rodentia, Cricetidae) in Brazil. Acta Theriologica, 37: 163 - 169.","Winge, H. 1887. Jordfunde og nulevende Gnavere (Rodentia) fra Lagoa Santa, Minas Geraes, Brasilien: Med udsigt over gnavernes indbyrdes slagtskab. E Museo Lundii, 1 (3): 1 - 178."]}

Delomys dorsalis (Hensel, 1872). Abh. König. Akad. Wiss. Berlin, p. 42. TYPE LOCALITY: Brazil, Rio Grande do Sul. DISTRIBUTION: Atlantic coastal region of SE Brazil and extreme NE Argentina. SYNONYMS: collinus, lechei, obscura, plebejus., Published as part of Guy G. Musser & Michael D. Carleton, 1993, Order Rodentia - Family Muridae, pp. 501-755 in Mammal Species of the World (2 nd Edition), Washington and London :Smithsonian Institution Press on page 700, DOI: 10.5281/zenodo.7353098

SUMMARYKaryotypes of ten species of Brazilian rodents, collected in the State of Sao Paulo are presented: Akodon (Thaptomys) nigrita nigrita (2 n = 52); Zygodontomys lasiurus (2 n = 34); Thomasomys (Delomys) dorsalis collinus (2 n = 82); Oxymycterus sp1. and Oxymycterus sp2. (2 n = 54); Calomys sp. (2 n = 66); Clyomys laticeps laticeps (2 n = 34); Euryzygomatomys guiara (2 n = 46); Proechimys iheringi iheringi (2 n = 62, 64) and Echimys sp. (2 n = 90).The analysis of 30 specimens of Zygodontomys lasiurus disclosed a diploid number of 34 chromosomes. In three female specimens the length of one X chromosome was half the length of the other, due to a deletion on the long arm. In this case, the probably normal X chromosome presents a subterminal centromere and is morphologically identified.A heteromorphic autosomal pair was found in Oxymycterus sp1. and Oxymycterus sp2.In Proechimys iheringi iheringi the male had a pair of dot chromosomes less than the female; such chromosomes might be centric fragments resul...

Dans la Foret Atlantique Bresilienne (FAB) il y a aux moins 57 especes de rongeurs dont la plupart sont omnivores. Ces especes consomment frequemment des fruits et des graines. Cependant, le role de ces rongeurs, comme frugivores ou granivores ou disseminateurs de graines, est assez mal connu. Dans cette etude, leur importance dans l'exploitation des fruits et des graines a ete evaluee pour huit especes de rongeurs captures dans le domaine de la Foret Atlantique. Les fruits et graines de 30 especes vegetales (23 genres, 15 familles) ont ete offerts a ces rongeurs maintenus en captivite. Apres 48 heures les donnees concernant le parametre d'exploitation des fruits et semences a ete evalue pour huit especes de petits rongeurs captures dans le domaine de la Foret Atlantique. Les fruits de 30 especes vegetales ont ete offerts aux animaux maintenus confines (23 genres, 15 familles). Apres 48 heures les donnees concernant la consommation de pulpe ou d'arille ont ete observees. Selon les especes on constate des differences dans l'exploitation des fruits et des graines. Les plus petits rongeurs Akodon serrensis, Oryzomys nigripes et Wilfredomys pictipes (26-45 g), Oecomys aff. concolor (84 g) qui est de taille moyenne, ont consomme surtout de la pulpe, et aussi des graines petites et moyennes (< 10 mm de diametre); Oryzomys russatus (91 g), rongeur de taille moyenne, s'est nourri de pulpe ainsi que de graines ayant jusqu'a 15 mm de diametre; les graines plus grandes comme celles de Cryptocarya moschata (Lauraceae), Eugenia melano-gyna et E. stictosepala (Myrtacea) sont restees intactes apres qu'il les ait manipulees. Un autre rongeur de taille moyenne, Delomys dorsalis (72 g), ainsi que Trinomys iheringi (274 g) et Nectomys squamipes (253 g) de grande taille, ont constitue un troisieme groupe qui a consomme autant de pulpe que des graines de la plupart des especes, quelle que soit leur taille. Il est fort possible que les deux dernieres especes ainsi qu'O. russatus soient les principaux rongeurs granivores de la Foret Atlantique Bresilienne.