Guy G. Musser

Description of a New Genus and Species of Rodent (Murinae, Muridae, Rodentia) from the Khammouan Limestone National Biodiversity Conservation Area in Lao PDR

Abstract Saxatilomys paulinae, a new genus and species of murid rodent in the Dacnomys Division is described. It is based on two whole specimens and 14 individuals represented by fragments recovered from owl pellets. The samples come from the Khammouan Limestone National Biodiversity Conservation Area in Khammouan Province in central Lao PDR. This tower karst landscape is part of the Quy Dat limestone massif, which extends eastward into north-central Vietnam (Binh Tri Thien Province). The new genus and species is morphologically (and probably phylogenetically) allied to species of Niviventer and Chiromyscus, which are also members of the Dacnomys Division, but its semispinous dark gray upperparts, dark frosted gray underparts, large, extremely bulbous footpads, and a combination of derived and primitive cranial and dental traits exclude it from membership in Niviventer, Chiromyscus, or any other described genus of Indo-malayan murid. The new species is likely petricolous, and is part of a small but unique community of small nonvolant mammals containing the petricolous gymnure, Hylomys megalotis, and hystricognath, Laonastes aenigmamus. All three species have been collected only in forested, rocky habitats of the Khammouan Limestone, but comparable environments in the adjacent Vietnamese portion of the Quy Dat limestone massif may harbor these same species specialized for living in forested, karstic landscapes.

Description of a New Genus and Species of Rodent (Murinae, Muridae, Rodentia) from the Tower Karst Region of Northeastern Vietnam

Abstract Tonkinomys daovantieni, a new genus and species of murid rodent in the Dacnomys Division, is described. It is represented by 14 adults collected from talus habitats in the forested tower karst landscape of the Huu Lien Nature Reserve of northeastern Vietnam. The combination of semispinous, dense, grayish black fur covering upperparts; a dark gray venter; gray ears; a thick, bicolored tail considerably shorter than length of head and body; and large, extremely bulbous footpads is unlike any other species of Indomalayan murid. Body size and build of the new rat, along with some cranial features, are similar to the Thai Leopoldamys neilli, but other cranial traits coupled with molar occlusal patterns resemble morphology in species of the Indomalayan Niviventer, Chiromyscus, and Saxatilomys. The new species is petricolous, includes insects in its diet, and was found only in talus composed of large limestone blocks. Its distribution in the reserve is likely patchy. Whether this limestone rat is restricted to the extensive karst regions of northeastern Vietnam or also occurs in southern China and elsewhere in the northern karst landscapes of Indochina, and Vietnam in particular, will be known only by conducting surveys in limestone regions outside of northeastern Vietnam.

Sulawesi Rodents: Description of a New Genus and Species of Murinae (Muridae, Rodentia) and Its Parasitic New Species of Sucking Louse (Insecta, Anoplura)

Abstract The murine rodent, Sommeromys macrorhinos, new genus and species, is described from a single specimen collected at 2400 m near the summit of Gunung Tokala in central Sulawesi. The species is insectivorous and a member of the tropical upper montane rain forest fauna of the island. With its small body, elongate rostrum, long and slender hind feet, very long tail, and brownish gray fur, S. macrorhinos superficially resembles the long-tailed and small-bodied shrew rat, Tateomys macrocercus, another Sulawesian upper montane forest endemic. Sommeromys macrorhinos, however, possesses a combination of derived external, cranial, and dental traits, along with a unique rostral shape, that dissassociates it from any relationship with not only T. macrocercus and its close allies T. rhinogradoides and Melasmothrix naso, but with also the large-bodied shrew rats of Sulawesi (Echiothrix) and those indigenous to the Philippines (Archboldomys, Rhyncomys, Chrotomys, and Celaenomys) and New Guinea (Neohydromys, Pseudohydromys, Microhydromys, and Mayermys). The rostral configuration of Sommeromys is unlike the architecture found in any other of the more than 1300 species in the entire Muridae. The new species has a derived cephalic arterial circulation, a pattern otherwise found only in Crunomys celebensis among Sulawesian murines. That species, although usually regarded as a shrew rat, also does not possess any of the external and cranial specializations defining the species of Melasmothrix, Tateomys, and Echiothrix. Crunomys and Sommeromys share a similar conformation of the zygomatic plate that is not found in any other Sulawesian murine, but this is a shared primitive feature. Whether the shared cephalic arterial circulation indicates a closer relationship between Crunomys celebensis and Sommeromys macrorhinos than to any other native Sulawesi species, despite the striking contrast between the two in body form and a combination of cranial and dental traits, or independent derivation in each species will have to be determined by phylogenetic analysis of all the Sulawesi species as well as pertinent samples from the Sunda Shelf and Indochina. A new species of sucking louse, Hoplopleura sommeri (Insecta, Anoplura, Hoplopleuridae), is also described from the new murine. A brief discussion on related species of Hoplopleura is included with emphasis on those species parasitizing hosts in the subfamily Murinae of family Muridae.

A New Species of the Rodent Genus Oecomys (Cricetidae: Sigmodontinae: Oryzomyini) from Eastern Bolivia, with Emended Definitions of O. concolor (Wagner) and O. mamorae (Thomas)

Abstract We describe a new species of Oecomys, O. sydandersoni (Cricetidae: Sigmodontinae), from the Parque Nacional Noel Kempff Mercado in eastern Bolivia. One of its diagnostic traits, a derived carotid circulatory plan, provides morphological evidence for its close relationship to O. concolor and O. mamorae among the 15 species of Oecomys currently recognized. Notwithstanding this shared trait, other morphological contrasts and morphometric analyses demonstrate the sharp differentiation of the eastern Bolivian form from both of those species. Oecomys sydandersoni, n. sp., is arboreal and was encountered above ground on limbs and woody vines only in densely wooded hummocks scattered through grassland, in contrast to adjacent closed tropical deciduous forest where three other species of Oecomys (O. bicolor, O. roberti, O. trinitatis) were obtained. The new species represents the fourth sigmodontine rodent to be named from this restricted region within eastern Bolivia since 1999. Its documentation served as a platform to summarize the nomenclatural history, morphological recognition, and geographic distribution of O. concolor (Wagner, 1845) and O. mamorae (Thomas, 1906) based on fresh examination of all type material and museum specimens.

Systematic review of endemic Sulawesi squirrels (Rodentia, Sciuridae), with descriptions of new species of associated sucking lice (Insecta, Anoplura), and phylogenetic and zoogeographic assessments of sciurid lice

Abstract Analyses of fur color patterns, morphometric data derived from external, cranial, and dental dimensions, and distributions of collection sites for voucher specimens form the basis for a taxonomic revision of Sulawesis endemic squirrel fauna. Eight species of tree squirrels in Rubrisciurus and Prosciurillus and two species of ground squirrels in Hyosciurus are recognized. All are diurnal and inhabit primary forest formations. Diet consists of fruit, nuts, seeds, and arthropods. Rubrisciurus rubriventer, the largest in body size, forages on the ground and in the lower canopy layer, is found throughout Sulawesi where primary forest persists, and occurs through an altitudinal range embracing tropical lowland evergreen and lower montane rain forests; it is absent from upper montane rain forest. Five species of arboreal squirrels comprise the Prosciurillus leucomus group, a cluster of species occupying the upper forest canopy: P. leucomus, known only from lowland and montane habitats in the northern peninsula and one offshore island; P. alstoni, recorded from lowland tropical evergreen rain forest in the eastern section of Sulawesis central core, the east-central and southeastern arms, and two southeastern islands; P. weberi, represented by a few specimens from the coastal lowlands of the southern core of Sulawesi; P. topapuensis, endemic to the western mountain block in Sulawesis central core and occurring along an altitudinal gradient from lowland evergreen rain forest to upper montane rain forest; and P. rosenbergii, the only species of squirrel collected on islands in the Sangihe Archipelago north of the northeastern tip of the northern peninsula. The Prosciurillus murinus group contains two species of small body size: P. murinus, found throughout Sulawesi and in all forest formations, from the coastal lowlands to mountaintops, and a forager in the lower canopy layers; and P. abstrusus, known only from montane forest habitats on Pegunungan Mekongga in the southeastern peninsula. Of two species of ground squirrels, Hyosciurus heinrichi occupies montane forest habitats in the western mountain block of Sulawesis central core. It is altitudinally parapatric to H. ileile, which inhabits lowland evergreen and lower montane rain forests in the western mountain block and northeastern lowlands of central Sulawesi, and montane forest on the northern peninsula. A slightly revised classification of Sciuridae is provided in which a new tribe, Exilisciurini, is proposed for the Bornean and Philippine Exilisciurus. Previously published results of morphological and molecular analyses point to Rubrisciurus, Prosciurillus, and Hyosciurus as a monophyletic cluster, the Hyosciurina, nested within a larger clade, the Nannosciurini, which along with Exilisciurini n. tribe and Funambulini, comprise the Nannosciurinae, one of the three subfamilies constituting Sciuridae, and one that contains most of the Indomalayan genera. The present diversity of species endemic to Sulawesi was derived from an ancient lineage that crossed a sea barrier from the Sunda Shelf to Sulawesi during the late Miocene. Eight new species of hoplopleurid sucking lice (Insecta, Anoplura) are described as parasitizing 8 of the 10 species of squirrels endemic to Sulawesi: Hoplopleura rubrisciuri from Rubrisciurus rubriventer, Hoplopleura leucomus from Prosciurillus leucomus, Hoplopleura alstoni from Prosciurillus alstoni, Hoplopleura topapuensis from Prosciurillus topapuensis, Hoplopleura murinus from Prosciurillus murinus, Hoplopleura abstrusus from Prosciurillus abstrusus, Hoplopleura heinrichi from Hyosciurus heinrichi, and Hoplopleura ileile from Hyosciurus ileile. Examples of Prosciurillus weberi and P. rosenbergii were surveyed but no lice were recovered. A phylogenetic analysis based on cladistic principles for six species of Sulawesian squirrel lice for which both sexes were available is presented and the results discussed with respect to host relationships. These new data are incorporated into a discussion covering zoogeography of global sciurid-sucking louse associations, emphasizing the Indomalayan squirrel fauna. Globally, members of 11 genera of Anoplura parasitize sciurids, a figure far exceeding the number of anopluran genera associated with any other mammalian family. Nine of these (the enderleinellids, Atopophthirus, Enderleinellus, Microphthirus, Phthirunculus, and Werneckia; the hoplopleurid, Paradoxophthirus; and the polyplacids, Johnsonpthirus, Linognathoides, and Neohaematopinus) are primary parasites of sciurids. The remaining two (the hoplopleurid Hoplopleura, and the polyplacid Polyplax) include representatives that are acquired (secondary) parasites of sciurids—the majority of species in these two louse genera parasitize other groups of mammals but a small number of species have transferred to squirrel hosts. Sciurid hosts and geographic distributions of these 11 anopluran genera are discussed. Historically, representatives of Hoplopleura colonized different sciurid hosts on several separate occasions with one known species on a North American tree squirrel (Sciurus), two described species on North American flying squirrels (Glaucomys), two species parasitizing North American species of chipmunks (Tamias and Eutamias), 14 described species from Indomalayan nannosciurine squirrels (Callosciurus, Tamiops, Rubrisciurus, Prosciurillus, Hyosciurus, and Funambulus), and one species parasitizing a Chinese xerine ground squirrel (Sciurotamias). The zoogeography of the seven sciurid-infesting louse genera known from Southeast Asia is discussed using data from nine different countries or regions (China, Taiwan, Thailand, peninsular Malaysia, Sumatra, Java, Borneo, the Philippines, and Sulawesi). A reduction in the number of sciuirid-infesting anopluran genera and species is apparent from mainland northern/western regions to insular southern/eastern regions with members of seven genera and 23 species described from China but only one genus and eight species from Sulawesi. The absence of known species of Hoplopleura from Bornean and Javanese squirrels suggests that such a fauna may await discovery on one or both of these islands. Six of the eight species of Hoplopleura found parasitizing species of endemic Sulawesi squirrels were recovered as a monophyletic clade from a phylogenetic analysis employing anatomical structures associated with male and female lice. (Two species of Sulawesi Hoplopleura are based on females and nymphs only and were not incorporated into the analysis.) The monophyletic cluster formed by the Sulawesian squirrel lice joined with the monophyletic assemblage containing the three Sulawesi squirrel genera—Rubrisciurus, Prosciurillus, and Hyosciurus—suggest that the ancestral squirrel lineage that arrived in Sulawesi during the late Miocene may have been carrying its unique Hoplopleura parasite.

Systematic Reviews of New Guinea Coccymys and “Melomys” Albidens (Muridae, Murinae) with Descriptions of New Taxa

Abstract A new species of the New Guinea endemic murine genus Coccymys is described, based on a small sample from Mt. Dayman and Mt. Simpson in the Maneau Range at the far eastern end of the Owen Stanley Ranges of eastern Papua New Guinea, and two specimens from the western portion of the Owen Stanleys, one from Smiths Gap near Mt. St. Mary, the other from Bulldog Road in the Wau area. Coccymys kirrhos, n. sp., is a vicariant relative of C. shawmayeri, which occurs in the Central Cordillera of Papua New Guinea extending from Mt. St. Mary in the east to the Telefomin region in the west. Coccymys shawmayeri in turn is the eastern montane vicariant of the western New Guinea C. ruemmleri, so far recorded only from the Snow Mountains in western New Guinea (Papua Province of Indonesia) and the eastern end of the Star Mountains over the border in the western section of Papua New Guinea. Coccymys ruemmleri and C. shawmayeri are regionally sympatric in western Papua New Guinea where the former is apparently restricted to high altitudes on the Star Mountains and the latter occurs at lower altitudes in the highlands bounding the Telefomin Valley. The ranges of C. shawmayeri and C. kirrhos, n. sp., overlap at the western section of the Owen Stanley Ranges, and both species have been caught at Bulldog Road, but in different years. This linearly distributed trio of species has been found only in the montane forests and alpine grasslands of the Central Cordillera—there are no records from mountains on Vogelkop Peninsula and the Huon Peninsula, nor from any of the north coast ranges. The new species is described within the context of rediagnosing the genus Coccymys, and documenting morphometric and geographic limits of C. ruemmleri and C. shawmayeri based on most specimens stored in collections of museums. This material consists primarily of museum study skins and accompanying skulls, some fluid-preserved specimens, skeletal fragments from modern samples of owl pellets, and Holocene and Late Pleistocene fossils (for C. ruemmleri only). All species of Coccymys are nocturnal and scansorial; stomach contents from samples of C. shawmayeri indicate the diet consists of seeds, fruit, and arthropods. The taxon albidens is represented by six modern examples collected at 2800 m and 3225 m in 1938 from the northern slopes of the Snow Mountains of western New Guinea, and three Late Pleistocene fossils obtained from the same region. The species was initially described as a Melomys (Tate, 1951); later an alliance with Coccymys was suggested (Flannery, 1990; Menzies, 1990; Musser and Carleton, 1993), but restudy of anatomical traits (derived solely from stuffed skins with accompaning skulls) reveals a degree of morphological divergence not only from species in Coccymys but from any other “Old Endemic” New Guinea murine. A new genus, Brassomys, sampled by only six modern specimens and three Late Pleistocene fossils, is proposed to embrace albidens. Morphological attributes of that species are contrasted primarily with those characterizing Coccymys, and secondarily with the genera Melomys, Paramelomys, Mammelomys, Protochromys, Abeomelomys, and Pogonomelomys. Biological aspects of albidens are unknown; however, particular external, cranial, and dental traits in combination strongly suggest the species is a nocturnal, arboreal/scansorial invertebrate predator.

A Systematic Review of Sulawesi Bunomys (Muridae, Murinae) with the Description of Two New Species

ABSTRACT Two new species of of Bunomys are described, B. karokophilus and B. torajae, both from the west-central mountain region of central Sulawesi. The descriptions are presented within the context of a systematic review of Bunomys in which are provided characteristics of the genus and species (external form, secondary sexual traits, spermatozoa, stomach morphology, skull, dentition, chromosomes); diagnoses, geographic and elevational distributions; sympatric, syntopic, and parapatric distributional relationships; morphological, distributional, and in some cases ecological comparisons among the species; natural histories for certain species derived from field observations; parasites; allocation of generic and specific synonyms; and documentation of subfossils for two of the species. Eight species are recognized; all are nocturnal, terrestrial, and endemic to the island of Sulawesi. Bunomys chrysocomus has been collected from most regions of the island and inhabits both lowland tropical evergreen and montane rain forests (elevational range u200a=u200a 250–2200 m). Bunomys coelestis is endemic to montane forests on Gunung Lompobatang, the high volcano at the southern end of the southwestern peninsula (1829–2500 m). Bunomys prolatus has been reported only from mountain forest on Gunung Tambusisi at the western end of the eastern peninsula (1829 m). Bunomys torajae, n. sp., is described from a small sample collected in montane forest on Gunung Gandangdewata at the southern end of the west-central mountain block (2500–2600 m). Bunomys fratrorum is currently documented only from the northeastern area of the northern peninsula where it occupies habitats in lowland tropical evergreen and montane rain forests (coastal plain to 1982 m). Bunomys andrewsi has been collected primarily in lowland tropical evergreen rain forests in the core of Sulawesi and on the eastern, southeastern, and southwestern peninsula (coastal plain to 1600 m). Bunomys penitus is strictly montane and recorded only from the west-central mountain block and Pegunungan Mekongga on the southeastern peninsula (1285–2287 m). Bunomys karokophilus, n. sp., is currently known only from lowland tropical evergreen rain forest in the northern portion of the west-central mountain block (823–1150 m). Analyses of morphometric traits (cranial and dental measurements) results in a phenetic relationship among the species in which B. chrysocomus, B. coelestis, B. prolatus, and B. torajae, n. sp., form one group characterized by small physical size and small molars, and B. fratrorum, B. andrewsi, B. penitus, and B. karokophilus another group in which larger physical size and heavier molars are the phenetic definers. Whether or not the integrity of this phenetic pattern will withstand testing by analyses of DNA sequences, it remains a convenient arrangement in which to present and define the eight species. The morphological, elevational, and ecological relationships among the four species of Bunomys (B. chrysocomus, B. andrewsi, B. penitus, and B. karokophilus, n. sp.) collected along my transect area in the northern portion of the west-central mountain block (presently known as Lore Lindu National Park) and comparison between them and the elevational distributions of the other murids encountered along the transect are described. Finally, a brief introduction to the species of murid rodents that have been recorded from mainland Sulawesi and nearby islands is provided, which defines the murine faunal context for the species of Bunomys. The treatment of Bunomys offered here focuses on definitions of the species as outlined by phenetic traits, elevational and geographic distributions, and the natural history characteristics that are available for some of the species, and does not cover an analysis of the phylogenetic relationships between Bunomys and other Indoaustralian murines.

Morphological and Geographic Definitions of the Sulawesian Shrew Rats Echiothrix leucura and E. centrosa (Muridae, Murinae), and Description of a New Species of Sucking Louse (Phthiraptera: Anoplura)

ABSTRACT Among the 15 known genera of murine rodents endemic to the island of Sulawesi, is the shrew rat genus Echiothrix. Physically large (length of head and body u200a=u200a 182–235 mm; weight u200a=u200a 215–310 g) with a bicolored tail typically longer than head and body (100%–135% of head and body length), elongate hind feet (48–55 mm), large ears (31–35 mm), long and thin muzzle, spinous fur, and tiny molars relative to size of skull (length of molar row u200a=u200a 12%–13% of occipitonasal length), Echiothrix was named and described in 1867 and through the years has been treated as monotypic or containing up to three species. Results from analyses of morphometric traits derived primarily from cranial and dental measurements document the presence of two species. Echiothrix leucura (Gray, 1867) is restricted to the northern peninsular mainland east of the Gorontalo region (00°31′ N, 123° 03′ E). This distribution is concordant with that of four other murids endemic to the northeastern tip of the northern peninsula: Bunomys fratrorum, Taeromys taerae, Rattus xanthurus, and R. marmosurus. Echiothrix centrosa Miller and Hollister, 1921 (Echiothix brevicula Miller and Hollister, 1921, is a synonym), is documented by specimens from the northern peninsula west of the Gorontalo region and in the central portion of the island; 19 other murine species are also known only from the core of Sulawesi. Whether the range of E. centrosa extends to the eastern, southeastern, and southwestern peninsulas is at present unknown. Echiothrix leucura has a more elongate skull compared with E. centrosa (greater lengths of skull, rostrum, diastema, and bony palate), a wider interorbital region, larger braincase, narrower bony palate and mesopterygoid fossa, shorter incisive foramina, and appreciably larger molars; the two species also differ in frequencies of particular molar cusps and cusplets. Both species of Echiothrix are nocturnal, terrestrial, and occupy habitats in tropical lowland evergreen rain forest. Natural history observations made in the field for Echiothrix centrosa show it to be primarily vermivorous; other natural history observations derived from field work in central Sulawesi are provided. One aspect of that natural history is the ectoparasitic load borne by E. centrosa. This shrew rat is host to at least four species of ticks (Haemaphysalis kadarsani, Haemaphysalis hystricis, Haemaphysalis sp. and Amblyomma sp.), a tiny fur mite (Listrophoroides echiothrix), mesostigmatid mites belonging to the genus Laelaps, currently undetermined chiggers, a flea (Farhangia quattuordecimdentata), and a new species of sucking louse described herein as Polyplax beaucournui. This louse has tibiotarsal claws adapted for grasping slender soft hairs in the pelage and not the wide host spines; female lice also attach their eggs only to these slender hairs. The closest relative of Echiothrix is probably Paucidentomys vermidax, another Sulawesian endemic shrew rat that is also vermivorous but lacks molars and has been collected only in montane forests. The present report documents morphological and distributional limits of species in Echiothrix, places one of those species in an ecological and parasitological landscape, and generally contributes to knowledge covering endemic murid species diversity and identifying unique zoogeographical areas on Sulawesi.

The valid generic name for red-backed voles (Muroidea: Cricetidae: Arvicolinae): restatement of the case for Myodes Pallas, 1811

Abstract In view of contradictions in the recent literature, the valid genus-group name to be applied to northern red-backed voles—Myodes Pallas, 1811, or Clethrionomys Tilesius, 1850—is reviewed. To develop the thesis that Myodes (type species, Mus rutilus Pallas, 1779) is the correct name, our discussion explores the 19th-century taxonomic works that bear on the relevant taxa, the transition in zoological codes apropos the identification of type species, and past nomenclatural habits in cases where no type species was originally indicated. We conclude that Myodes is the senior name to use for the genus-group taxon that includes the Holarctic species rutilus and frame this conclusion within a synonymy of the genus.

Characterisation of the endemic Sulawesi Lenomys meyeri (Muridae, Murinae) and the description of a new species of Lenomys

In 1969, DJ Mulvaney sent me a batch of subfossils excavated by him and his colleagues from caves and rock-shelters in the Makassar region of Sulawesi (Mulvaney and Soejono, 1970). Among them are samples from a cave (Leang Burung 1) containing examples of Lenomys meyeri, a large-bodied rat endemic to Sulawesi, and a single right dentary with an intact molar row that is from a smaller-bodied Lenomys, which represents a new species. The small Lenomys along with specimens of L. meyeri were excavated from a level with a radiocarbon date of 2820 ± 210 BP, and other examples of L. meyeri were found in an underlying stratum dated at 3420 ± 400 BP (Mulvaney and Soejono, 1970: 171).