Heteromys anomalus is widely distributed along the Caribbean coast of South America and had been considered the only spiny pocket mouse present in Venezuela for several decades. Recent taxonomic studies in western Venezuela, however, have documented the presence of H. australis from the Cordillera de Mérida and described H. oasicus from the Península de Paraguaná. Here, we revise the genus Heteromys in central and eastern Venezuela as well as in Trinidad and Tobago. Morphological comparisons with samples of H. anomalus from throughout its known range in Venezuela and with representatives of all other recognized species of the genus indicate the existence of a species new to science, which we describe as Heteromys catopterius (the Overlook Spiny Pocket Mouse). This species ranges from 350 to 2425 m in elevation in the Cordillera de la Costa in northern Venezuela, with the vast majority of records above ca. 700 m. In central and eastern Venezuela, H. anomalus is found in the surrounding lowlands and lower slopes of the Cordillera. Externally, H. catopterius is darker than H. anomalus and lacks the distinctly rounded ears of that species. The new species averages larger than H. anomalus for most external and cranial measurements. Cranially, the two species have differences in proportion; the skulls of H. catopterius are proportionately wider (less elongated) than those of H. anomalus, with a relatively wider interorbital constriction, wider interparietal, and more inflated braincase. Heteromys catopterius occurs in wet montane forests (especially cloud forests) in four highland areas of the Cordillera de la Costa: the main Aragua-Carabobo chain, the El Ávila massif, the Serranía del Interior, and the Macizo Oriental. Presumably, the warm, dry lowlands of the Depresión de Unare represent a barrier for the species, separating populations in the Macizo Oriental from the more westerly populations. Large areas of the known ranges of both H. catopterius and H. anomalus are protected in the Venezuelan network of protected areas.

The status and distribution of eight species-group taxa of the Oryzomys couesi group (Rodentia: Cricetidae: Sigmodontinae) described from western Mexico are evaluated based on morphological and morphometric comparisons. Four of these are recognized as valid species within the region: Oryzomys albiventer Merriam, 1901 (including molestus Elliot, 1903), from inland plateau of the Mesa de Anáhuac; O. couesi mexicanus J.A. Allen, 1897 (including bulleri J.A. Allen, 1897; lambi Burt, 1934; rufus Merriam, 1901), from Pacific coastal plain, contiguous lower mountain slopes, and interior valleys along the Ríos Tepalcatepec–Balsas; O. nelsoni Merriam, 1898, from Isla María Madre; and O. peninsulae Thomas, 1897, from the southern tip of the Baja California Peninsula. Three other taxa named from uplands in interior Mexico—aztecus Merriam, 1901; crinitus Merriam; 1901; and regillus Goldman, 1915—are provisionally retained within O. couesi, but further study of their specific stature and relationships is required. The recommended taxonomic changes within western Mexico serve to discuss directions for future revisionary research that will refine the definition and distribution of O. couesi sensu stricto in Middle America.

In parallel with the growing body of molecular data bearing on the relationships of muroids, particularly subterranean lineages, the relevant fossil record has improved to the point that its data constrain scenarios of evolution about both the timing and mode of evolution of burrowing muroids, especially bamboo rats, blind mole rats, and zokors. Morphologists have considered these groups phylogenetically distinct from each other, but the three lineages appear to be related as a monophyletic Family Spalacidae, sister taxon to all other living muroids, based on both nuclear and mitochondrial genes. Although living genera are fully subterranean, the fossil record shows that the three groups evolved burrowing characteristics independently. Bamboo rats (Rhizomyinae) have the longest fossil record, extending into the Late Oligocene, but do not show fossorial traits until the Late Miocene. Blind mole rats (Spalacinae) have a fossil record nearly that long, and its early members also lack burrowing traits. Zokors (Myospalacinae) show characteristics considered derived relative to other groups, and have a shorter fossil record. The fossil record of the Tribe Rhizomyini, living Asian bamboo rats, extends to about 10 million years ago, with early species distinct at the generic level from living Rhizomys. The oldest well-known species assignable to an extant genus is Rhizomys (Brachyrhizomys) shansius from the early Pliocene of Yushe Basin, China, north of the geographic range of modern Rhizomys. A hypothesis of close relationship of bamboo rats, blind mole rats, and zokors leads to a reevaluation of affinities of certain Asian fossil taxa and reevaluation of polarity of some features, but molecular data are not yet robust enough to clarify interrelationships of the groups. Morphological and fossil data suggest that myospalacines are more closely related to rhizomyines than to spalacines, and that known Early Miocene rhizomyines are close to the stem zokor morphotype.

A new species of the rodent genus Reithrodontomys (Cricetidae: Neotominae) is described from Cerro Asunción in the western Cordillera de Talamanca, Costa Rica. The long tail, elongate rostrum, bulbous braincase, and complex molars of the new species associate it with members of the subgenus Aporodon, tenuirostris species group. In its diminutive size and aspects of cranial shape, the new species (Reithrodontomys musseri, sp. nov.) most closely resembles R. microdon, a form known from highlands in Guatemala and Chiapas, Mexico. In the course of differentially diagnosing the new species, we necessarily reviewed the Costa Rican and Panamanian subspecies of R. mexicanus based on morphological comparisons, study of paratypes and vouchers used in recent molecular studies, and morphometric analyses. We recognize Reithrodontomys cherrii (Allen, 1891) and R. garichensis Enders and Pearson, 1940, as valid species, and allocate R. mexicanus potrerograndei Goodwin, 1945, as a subjective synonym of R. brevirostris Goodwin, 1943. Critical review of museum specimens collected subsequent to Hooper's (1952) revision is needed and would do much to improve understanding of Reithrodontomys taxonomy and distribution in Middle America.

After almost 70 years of stability following publication of Andersen's (1912) monograph on the group, the systematics of megachiropteran bats (Chiroptera: Pteropodidae) was thrown into flux with the advent of molecular phylogenetics in the 1980s—a state where it has remained ever since. One particularly problematic group has been the Austromalayan Harpyionycterinae, currently thought to include Dobsonia and Harpyionycteris, and probably also Aproteles. In this contribution we revisit the systematics of harpyionycterines. We examine historical hypotheses of relationships including the suggestion by O. Thomas (1896) that the rousettine Boneia bidens may be related to Harpyionycteris, and report the results of a series of phylogenetic analyses based on new as well as previously published sequence data from the genes RAG1, RAG2, vWF, c-mos, cytb, 12S, tVal, 16S, and ND2. Despite a striking lack of morphological synapomorphies, results of our combined analyses indicate that Boneia groups with Aproteles, Dobsonia, and Harpyionycteris in a well-supported, expanded Harpyionycterinae. While monophyly of this group is well supported, topological changes within this clade across analyses of different data partitions indicate conflicting phylogenetic signals in the mitochondrial partition. The position of the harpyionycterine clade within the megachiropteran tree remains somewhat uncertain. Nevertheless, biogeographic patterns (vicariance-dispersal events) within Harpyionycterinae appear clear and can be directly linked to major biogeographic boundaries of the Austromalayan region. The new phylogeny of Harpionycterinae also provides a new framework for interpreting aspects of dental evolution in pteropodids (e.g., reduction in the incisor dentition) and allows prediction of roosting habits for Harpyionycteris, whose habits are unknown.

A single specimen of a small mouse from Mt. Banahaw–San Cristobal Natural Park, Quezon Province, Luzon Island, Philippines, is here described as a new genus and species. It is easily distinguished from all other murids by its small size (15 g), rusty orange fur, mystacial vibrissae that are two-thirds the length of head and body, postocular patch of bare skin with long vibrissae arising within it, long tail with elongated hairs only on the posterior quarter, ovate ears, procumbent incisors that are deeply notched at the tip, and other distinctive characters. Both morphological and molecular data (from two nuclear genes) indicate that the new taxon is a member of the endemic Philippine clade of “giant cloud rats,” some of which weigh up to 2.6 kg. It is most closely related to the genus Carpomys, which includes the smallest previously known member of the clade (ca. 125 g), but differs from it in many features. The discovery of this new taxon reveals an even greater degree of diversification within the giant cloud rat clade than recognized previously, and adds to the 21 previously known genera of mammals endemic to the Philippines. The new mouse was captured in regenerating lowland rain forest located only 80 kilometers from Manila. This discovery highlights the importance of protecting regenerating tropical lowland rain forest, as well as the few remaining tracts of old-growth lowland rain forest on Luzon.

Morphological investigations involving nearly all available museum material representing New Guinea “moss-mice” (rodents traditionally classified in the genera Pseudohydromys, Neohydromys, Mayermys, and Microhydromys) reveal outstanding undiagnosed taxic diversity (a minimum of 16 species, versus the eight species previously described) and allow for redefinition of generic boundaries among these little-studied rodents. Apart from Microhydromys Tate and Archbold, 1941 (comprising two species, as recently revised by Helgen et al., in press), herein we recognize two genera of New Guinea moss-mice: Pseudohydromys Rümmler, 1934 (now incorporating Neohydromys Laurie, 1952, Mayermys Laurie and Hill, 1954, and “Microhydromys” musseri Flannery, 1989) and a newly described genus, Mirzamys. Species of Pseudohydromys are recorded from montane areas throughout New Guinea (elevations spanning 600 to at least 3800 meters), including the mountain ranges of the Central Cordillera, the Huon Peninsula, and the North Coastal ranges. We diagnose and review 12 species of Pseudohydromys, including six species described as new. The new genus Mirzamys is erected to accommodate two newly described species of small terrestrial rodents from middle and upper montane forests and subalpine grassland edges (1900–3450 m) in the mountains of central New Guinea. Together these two new species represent a distinctive hydromyin lineage that resembles the terrestrial New Guinea hydromyin genera Pseudohydromys and Paraleptomys in various traits. Ecological attributes of all recognized moss-mice taxa, both previously and newly described, are reviewed in light of all information currently available about their biology.

A new species of Graphiurus, G. walterverheyeni, is described. It is represented by two young adults, a female (holotype) and male (paratype), obtained from two sites in the central Congo Basin, Democratic Republic of the Congo. The new species is the possible morphological and phylogenetic counterpart of G. crassicaudatus, endemic to West Africa. Although the new species resembles G. crassicaudatus in texture and coloration of pelage, along with certain derived cranial features, G. walterverheyeni, n. sp., is separated not only by its much smaller body size as evidenced by the significant contrasts in external, cranial, and dental metrics between the two species, but also by proportional differences.

The South Central faunal region of equatorial Africa (Grubb, 1978, 1982, 2001; Colyn, 1991; Colyn and Van Rompaey, 1994; Happold, 1996), and the Salonga-Lukenie-Sankuru landscape (Congo Basin Forest Partnership, 2006), identify the biogeographic landscape of G. walterverheyeni, n. sp. Scant habitat information associated with the specimens suggests that this Congo Basin endemic occurs in seasonally flooded tropical lowland forest formations. Two other species of Graphiurus, G. lorraineus and G. surdus, are broadly sympatric with the new species, but neither has been recorded from the two collection localities.

Determining species diversity of sub-Saharan dormice embraces epidemiological concerns in addition to strictly taxonomic and biogeographic inquiries. The first documented outbreak of human monkeypox outside Africa occurred in the midwestern United States in 2003 and was associated with a shipment of captive mammals (Funisciurus sp., Heliosciurus sp., Cricetomys sp., Atherurus sp., Hybomys sp., and Graphiurus sp.) from Ghana (Guarner et. al., 2004). Following this outbreak, certain species of African dormice occurring in West and Central Africa are currently being scrutinized as possible hosts of monkeypox virus (Orthopoxviridae), which can produce a severe illness in humans resembling smallpox (Hutson et al., 2007; Levine et al., 2007). Understanding the ecology and epidemiology of this virus requires correct identification of mammalian host species so that accurate, relevant geographic and ecological data can be analyzed.

The species of Crocidura occurring in southern China, northern Myanmar and Vietnam, are reviewed and defined based on morphology and multivariate analyses. Three new species are described: C. cranbrooki from northern Myanmar, C. annamitensis from the Annamite Mountains of Vietnam, and C. guy from the Viet Bac limestone region in northeastern Vietnam. Enhanced comparative descriptions, distribution, and remarks on taxonomy are provided for each of the other nine species previously reported from the region: C. fuliginosa, C. attenuata, C. sokolovi, C. vorax, C. rapax, C. indochinensis, C. wuchihensis, C. kegoensis, and C. zaitsevi.

Six species of Paraguayan didelphid marsupials (opossums) were described by the Spanish naturalist Félix de Azara (1742–1821), whose nontechnical accounts were the basis for Latin binomials in current use for several species. Unfortunately, some of Azara's descriptions are problematic and have long been a source of taxonomic confusion. In particular, the names currently used for two species of Thylamys are difficult to reconcile with Azara's text. Herein we review the nomenclatural status of Azara's opossums and discuss relevant issues that affect binomial usage. Among other results, we report the rediscovery of the holotype of Caluromys lanatus (Olfers, 1818), and we designate neotypes to preserve current usage of the names Thylamys macrurus (Olfers, 1818) and T. pusillus (Desmarest, 1804).

The skull and mandible, with complete dentitions, of an Orellan rodent are described as a new genus and species of Eumyinae (Rodentia, Muroidea, Cricetidae) based on a combination of unique and shared features: small molar series compared to skull size, featherlike diagonal ridges on surface of lower incisor enamel, rounded triangular shape of M3, and flat interorbital roof and separate temporal crests.