Browsing by Author "Patton, James L."
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Item Mammals of the Rio Juruá and the evolutionary and ecological diversification of Amazonia. Bulletin of the AMNH ; no. 244([New York] : American Museum of Natural History, 2000) Patton, James L.; Da Silva, Maria Nazareth F.; Malcolm, Jay R.We describe the nonvolant mammal fauna of the Rio Juruá of the western Amazon of Brazil, based on collections made during a year-long survey of the river. We, along with our colleagues Drs. Claude Gascon and Carlos Peres, designed the field project to examine the effects of the river on the differentiation among terrestrial vertebrates (mammals, birds, and amphibians and reptiles) at both the community and population levels. This monograph examines only the patterns of geographic variation and community structure of the small-bodied mammals. Species inventories were made at 16 primary trapping localities divided into eight pairs of cross-river sites, with two pairs in each of four regions from near the mouth to the headwaters of the Rio Juruá. A total of 81 species of nonvolant mammals were obtained, including nine new to science. Four of these are described herein; the others have been described elsewhere. We used a standardized trapping protocol to assess community structure at each of the 16 localities that included terrestrial and canopy trap stations in floodplain (várzea) and upland (terra firme) forest formations. Supplemental trapping was done in secondary habitats at all sites. We describe these sites, the trap effort expended, and the placement of trap stations relative to local habitats. We also describe each species of marsupial, sciurid rodent, murid rodent, and echimyid rodent encountered; comment on their systematics; and summarize aspects of habitat use, life history, geographic distribution, and geographic differentiation based on morphological and molecular traits. We examine patterns of differentiation in the mitochondrial cytochrome-b gene for samples of 41 of the 45 species of marsupials and rodents obtained within the Rio Juruá Basin, and discuss these patterns from the perspective of the entire Amazon and, in some cases, the Mata Atlantica of coastal Brazil. We also examine patterns of community organization within the Rio Juruá basin and throughout Amazonia, drawing attention to the geographic distribution of what appear to be major faunal units that are independent of habitat differences. Finally, we use principles of phylogeography to analyze patterns of geographic differentiation among the nonvolant mammals with regard to the Riverine Barrier Hypothesis. We show that, while there are few examples of taxa for which the Rio Juruá is apparently a barrier, most taxa either are largely undifferentiated throughout the basin or are sharply divided into reciprocally monophyletic mtDNA haplotype clades separable into upriver and downriver units. We argue that the concordance in the geographic placement of clade boundaries suggests a common history; moreover, both the age of these clades and their geographic position in relation to underlying geological features suggest that landform evolution has been an important, but underappreciated component of diversification within western Amazonia.Item A new species of Oryzomys (Rodentia, Muridae) from eastern Bolivia. American Museum novitates ; no. 3478(New York, NY : American Museum of Natural History, 2005) Emmons, Louise; Patton, James L.Specimens of Oryzomys referable to the megacephalus complex (Musser et al., 1998) collected in the Parque Nacional Noël Kempff Mercado (PNNKM), eastern Bolivia, are discriminated from three other currently recognized species of that group (O. megacephalus, O. perenensis, O. laticeps) by analysis of cranial morphometrics and molecular sequence of the cytochrome b gene. The Bolivian sample has the closest genetic relationship to O. perenensis (Kimura 2-parameter genetic distance x 100: 14.8) and O. laticeps (distance 12.0), but the genetic distance is large. The Bolivian sample is clearly separated from the others by both principal component and discriminant function analyses of cranial and body variables. We here describe it as a new species. Morphologically, it is intermediate in size, along with O. perenensis, between the smaller O. megacephalus and the larger-bodied O. laticeps. In pelage color and occlusal pattern it closely resembles O. megacephalus. The geographic range appears to be a relatively small area of the western basin of the Río Itenez that drains easternmost Santa Cruz and Beni Departments. Genetically verified populations of the four species are thus far allopatric, with the known range of the new species wedged between the geographic ranges of O. perenensis to the west and O. megacephalus to the east.Item A review of the genus Isothrix (Rodentia, Echimyidae). American Museum novitates ; no. 2817(New York, N.Y. : American Museum of Natural History, 1985) Patton, James L.; Emmons, Louise."Two species of the echimyid rodent genus Isothrix are recognized within the Amazon and upper Orinoco basins of South America based on color and color pattern, bacular morphology, cranial morphometrics, and karyotype. These represent significant departures in the previously recognized name combinations: I. bistriata Wagner, with two geographic races (bistriata (including villosa Deville, negrensis Thomas, molliae Thomas, and boliviensis Petter and Cuenca Aguirre) and orinoci Thomas), and I. pagurus Wagner. No localities of sympatric contact between these two species are known, although their ranges come very close in the general vicinity of Manaus in central Brazil"--P. [1].Item Systematic studies of oryzomyine rodents (Muridae) : the identity of Oecomys phelpsi Tate. American Museum novitates ; ; no. 2961.(New York, N.Y. : American Museum of Natural History, 1989) Musser, Guy G.; Patton, James L.Item Two new species of Oxymycterus (Rodentia) from Peru and Bolivia. American Museum novitates ; no. 2898(New York, N.Y. : American Museum of Natural History, 1987) Hinojosa P., Flavio.; Anderson, Sydney, 1927-; Patton, James L."Two new species of Oxymycterus were recently discovered in the yungas of Peru and Bolivia. Both are much smaller than any species previously known. A description of the two species and a review of the characters of the oxymycterine group suggest certain relationships. Some shared characters suggest monophyly for a subgroup of the tribe Akodontini including the genera Oxymycterus, Podoxymys, Microxus, Lenoxus, Geoxus, and Blarinomys. However some of the shared characters may be results of convergence, and electrophoretic data suggest that at least Microxus does not belong with this group. Thus, the concept of an oxymycterine group remains unclear"--P. [1].