Browsing by Author "Jansa, Sharon A."
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Item Archboldomys (Muridae, Murinae) reconsidered : a new genus and three new species of shrew mice from Luzon Island, Philippines. (American Museum novitates, no. 3754)(American Museum of Natural History., 2012-09-14) Balete, Danilo S., 1960-; Rickart, Eric A.; Heaney, Lawrence R.; Alviola, Phillip A.; Duya, Melizar V.; Duya, Mariano Roy M.; Sosa, Timothy.; Jansa, Sharon A.Shrew mice of the genus Archboldomys are poorly known members of an endemic clade of vermivorous/insectivorous murid rodents confined to Luzon Island, Philippines. Three species of these small, ground-living, diurnal mice were previously known, all from a handful of specimens from a few localities. The pattern of morphological and genetic differentiation among additional specimens of shrew mice from our recent field surveys in the Central Cordillera and Sierra Madre mountains of Luzon document the presence of two distinct species groups within Archboldomys as previously defined, as well as three new species. Gene-sequence data from the mitochondrial cytochrome b and nuclear IRBP genes confirm the existence of six distinct species, but also show that Archboldomys, as previously defined, is composed of two clades that are not sister taxa. Reevaluation of the presumed morphological synapomorphies among these shrew mice, together with analyses of karyological and gene-sequence data, support the following: (1) erection of Soricomys, new genus; (2) transfer of A. kalinga and A. musseri to Soricomys; and (3) recognition of Archboldomys maximus, n. sp., Soricomys leonardocoi, n. sp., and Soricomys montanus, n. sp. The new genus and species are described, and their phylogenetic relationships, biogeography, and conservation are discussed.Item Craniodental morphology and phylogeny of marsupials (Bulletin of the American Museum of Natural History, no. 457)(American Museum of Natural History., 2022-06-28) Beck, Robin M. D.; Voss, Robert S.; Jansa, Sharon A.The current literature on marsupial phylogenetics includes numerous studies based on analyses of morphological data with limited sampling of Recent and fossil taxa, and many studies based on analyses of molecular data with dense sampling of Recent taxa, but few studies have combined both data types. Another dichotomy in the marsupial phylogenetic literature is between studies focused on New World taxa and those focused on Sahulian taxa. To date, there has been no attempt to assess the phylogenetic relationships of the global marsupial fauna based on combined analyses of morphology and molecular sequences for a dense sampling of Recent and fossil taxa. For this report, we compiled morphological and molecular data from an unprecedented number of Recent and fossil marsupials. Our morphological data consist of 180 craniodental characters that we scored for 97 terminals representing every currently recognized Recent genus, 42 additional ingroup (crown-clade marsupial) terminals represented by well-preserved fossils, and 5 outgroups (nonmarsupial metatherians).Our molecular data comprise 24.5 kb of DNA sequences from whole-mitochondrial genomes and six nuclear loci (APOB, BRCA1, GHR, RAG1, RBP3 and VWF) for 97 marsupial terminals (the same Recent taxa scored for craniodental morphology) and several placental and monotreme outgroups. The results of separate and combined analyses of these data using a wide range of phylogenetic methods support many currently accepted hypotheses of ingroup (marsupial) relationships, but they also underscore the difficulty of placing fossils with key missing data (e.g., †Evolestes), and the unique difficulty of placing others that exhibit mosaics of plesiomorphic and autapomorphic traits (e.g., †Yalkaparidon). Unique contributions of our study are (1) critical discussions and illustrations of marsupial craniodental morphology including features never previously coded for phylogenetic analysis; (2) critical assessments of relative support for many suprageneric clades; (3) estimates of divergence times derived from tip-and-node dating based on uniquely taxon-dense analyses; and (4) a revised, higher-order classification of marsupials accompanied by lists of supporting craniodental synapomorphies. Far from the last word on these topics, this report lays the foundation for future research that may be enabled by the discovery of new fossil taxa, better-preserved material of previously described taxa, novel morphological characters (e.g., from the postcranium), and improved methods of phylogenetic analysis.Item Mammalian diversity and Matses ethnomammalogy in Amazonian Peru. Part 3, Marsupials (Didelphimorphia). (Bulletin of the American Museum of Natural History, no. 432)(American Museum of Natural History., 2019-06-14) Voss, Robert S.; Fleck, David W. (David William), 1969-; Jansa, Sharon A.This report is the third in our monographic series on mammalian diversity and Matses ethnomammalogy in the Yavarí-Ucayali interfluvial region of northeastern Peru. Based on taxonomic analysis of specimens collected in the region, we document the occurrence of 19 species of marsupials in the genera Caluromys, Glironia, Hyladelphys, Marmosa, Monodelphis, Metachirus, Chironectes, Didelphis, Philander, Gracilinanus, and Marmosops. Our principal taxonomic results include the following: (1) we provide a phylogenetic analysis of previously unpublished mitochondrial DNA (mtDNA) sequence data for Caluromys that supports the reciprocal monophyly of all currently recognized species in the genus but reveals substantial heterogeneity in one extralimital taxon; (2) we explain why Marmosa constantiae is the correct name for the southwestern Amazonian taxon previously known as Mar. demerarae, and we diagnose Mar. constantiae from Mar. rapposa, a superficially similar species from southern Peru, eastern Bolivia, and central Brazil; (3) we explain why Mar. rutteri is the correct name for one of the Amazonian species currently known as Mar. regina, and we restrict the latter name to the transAndean holotype; (4) we recognize Metachirus myosuros as a species distinct from Met. nudicaudatus based on morphological comparisons and a phylogenetic analysis of new mtDNA sequence data; and (5) we name a new species of Marmosops to honor the late Finnish-Peruvian naturalist Pekka Soini. Of the 19 marsupial species known to occur in the Yavarí-Ucayali interfluve, 16 have been recorded in sympatry at Nuevo San Juan, the Matses village where we based most of our fieldwork from 1995 to 1999. We explain why we believe the marsupial species list from Nuevo San Juan to be complete (or nearly so), and we compare it with a species list obtained by similarly intensive fieldwork at Paracou (French Guiana). Although Nuevo San Juan and Paracou are 2500 km apart on opposite sides of Amazonia, the same opossum genera are present at both sites, the lists differing only in the species represented in each fauna. We briefly discuss current explanations for spatial turnover in species of terrestrial vertebrates across Amazonian landscapes and provide evidence that the upper Amazon is a significant dispersal barrier for marsupials. Marsupials are not important to the Matses in any way. In keeping with their cultural inattention to mammals that are inconspicuous, harmless, and too small to be of dietary significance, the Matses lexically distinguish only a few kinds of opossums, and they are not close observers of opossum morphology or behavior.Item Molecular systematics of mouse opossums (Didelphidae, Marmosa) : assessing species limits using mitochondrial DNA sequences, with comments on phylogenetic relationships and biogeography. (American Museum novitates, no. 3692)(American Museum of Natural History., 2010) Gutiérrez, Eliécer E.; Jansa, Sharon A.; Voss, Robert S.The genus Marmosa contains 15 currently recognized species, of which nine are referred to the subgenus Marmosa, and six to the subgenus Micoureus. Recent revisionary research based on morphological data, however, suggests that the subgenus Marmosa is more diverse than the currently accepted taxonomy indicates. Herein we report phylogenetic analyses of sequence data from the mitochondrial cytochrome-b gene representing 12 of the 14 morphologically defined taxa recently treated as valid species of Marmosa (Marmosa) in the aforementioned revisionary work. These data provide a basis for testing the monophyly of morphologically defined taxa in the subgenus Marmosa, and they afford the first opportunity to assess phylogenetic relationships among the majority of species currently referred to the genus. Ten of 11 species of Marmosa (Marmosa) represented by multiple sequences in our analyses were recovered as monophyletic. In contrast, our samples of M. mexicana were recovered as two deeply divergent haplogroups that were not consistently associated as sister taxa. Among other results, our analyses support the recognition of M. isthmica and M. simonsi as species distinct from M. robinsoni, and the recognition of M. macrotarsus and M. waterhousei as species distinct from M. murina. The validity of three other species long recognized as distinct (M. rubra, M. tyleriana, and M. xerophila) is also clearly supported by our results. Although cytochrome-b sequence data are not consistently informative about interspecific relationships in this study, we found strong support for several clades, including (1) the subgenus Micoureus; (2) a group comprised of Marmosa macrotarsus, M. murina, M. tyleriana, and M. waterhousei; (3) a group comprised of M. robinsoni and M. xerophila; and (4) a group comprising all of the species in the subgenus Marmosa that occur north and west of the Andes (M. isthmica, M. mexicana, M. robinsoni, M. simonsi, M. xerophila, and M. zeledoni). Our discovery of the latter clade suggests that the Andes may have played a major role in the early diversification of this speciose radiation of small Neotropical marsupials.Item A new species of Marmosops (Marsupialia, Didelphidae) from the Pakaraima Highlands of Guyana, with remarks on the origin of the endemic Pantepui mammal fauna. (American Museum novitates, ; no. 3778)(American Museum of Natural History., 2013-06-21) Voss, Robert S.; Lim, Burton K.; Díaz-Nieto, Juan F.; Jansa, Sharon A.A new species of the didelphid marsupial genus Marmosops is described from the Pakaraima Highlands of western Guyana and from two highland sites in eastern Venezuela. All known specimens were collected on sandstone table mountains (eroded fragments of the Roraima Formation) in the eastern subregion of Pantepui. The new species, M. pakaraimae, is one of only seven mammals known to be endemic to Pantepui, and phylogenetic analyses of cytochrome-b sequence data indicate that its sister taxon is M. parvidens, a geographically adjacent lowland species. Our results, together with those from phylogenetic studies of other Pantepui endemic mammals, suggest that at least some of these highland taxa evolved from lowland species in the late Cenozoic and are neither ancient relicts of tepui vicariance nor the descendents of long-distance-dispersing Andean progenitors.Item On the contents of Gracilinanus Gardner and Creighton, 1989, with the description of a previously unrecognized clade of small didelphid marsupials. American Museum novitates ; no. 3482(New York, NY : American Museum of Natural History, 2005) Voss, Robert S.; Lunde, Darrin P.; Jansa, Sharon A.Five nominal species of small didelphid marsupials previously referred to Gracilinanus differ conspicuously from the type species (G. microtarsus) and from all of the other valid taxa that we recognize as members of that genus (G. aceramarcae, G. agilis, G. dryas, G. emiliae, G. marica). These anomalous forms can be distinguished morphologically from Gracilinanus (in the strict sense just defined) by lacking maxillary palatal vacuities, a secondary foramen ovale, and a rostral process of the premaxillae; in addition, P3 is taller than P2, and accessory cusps are often present on C1. A new genus, Cryptonanus, is described to contain these forms, all of which are provisionally recognized as valid species: C. agricolai, C. chacoensis, C. guahybae, C. ignitus, and C. unduaviensis. Separate and combined phylogenetic analyses of nonmolecular data and nuclear gene sequences suggest that Cryptonanus and Gracilinanus (sensu stricto) are reciprocally monophyletic and closely related, although they were not consistently recovered as sister taxa in any analysis. Available specimen records document that Cryptonanus is widely distributed in mostly unforested tropical, subtropical, and temperate biomes south of the Amazon River (from ca. 7°S in the Brazilian state of Ceará to ca. 34°S in the Argentinian province of Buenos Aires), but significant range extensions could be expected from pitfall trapping in extralimital savanna landscapes. Scant field data suggest that species of Cryptonanus may often be associated with wet or seasonally inundated grasslands, an unusual habitat for small didelphids.Item On the relationships of "Marmosa" formosa Shamel, 1930 (Marsupialia, Didelphidae), a phylogenetic puzzle from the chaco of northern Argentina. American Museum novitates ; no. 3442(New York, NY : American Museum of Natural History, 2004) Voss, Robert S.; Gardner, Alfred L.; Jansa, Sharon A.The holotype and only known specimen of Marmosa formosa Shamel, a nominal species currently synonymized with Gracilinanus agilis Burmeister, is strikingly unlike any other known didelphid marsupial. Phylogenetic analyses based on nonmolecular characters and IRBP sequences suggest that formosa is either the sister-taxon of Thylamys (including Lestodelphys) or Monodelphis. Because neither alternative is strongly supported by the data at hand, and because including formosa in Thylamys or in Monodelphis would compromise the diagnosability of those taxa, a new genus--Chacodelphys--is proposed to contain it. Currently known only from northern Argentina, Chacodelphys formosa may be widely distributed in the Chaco and other adjacent Neotropical biomes.Item Phylogenetic relationships and classification of didelphid marsupials, an extant radiation of New World metatherian mammals. (Bulletin of the American Museum of Natural History, no. 322)(2009) Voss, Robert S.; Jansa, Sharon A.This report summarizes a decade of morphological and molecular research on the phylogenetic relationships of didelphid marsupials (opossums), a substantially intact radiation of New World metatherian mammals. We review the comparative morphology of Recent opossums, emphasizing those anatomical systems from which taxonomically useful information is available for the majority of living genera and species, namely the integument, cranium, and dentition. Morphological similarities and differences among didelphids and other plesiomorphic marsupials (caenolestids, microbiotheriids, dasyurids, and peramelids) are also described. These observations, representing evolved differences in diverse functional-morphological systems, together with karyotypic information gleaned from the literature, provide the basis for coding 129 phylogenetic characters that we scored for 44 ingroup and seven outgroup taxa. Published information about the size, internal organization, chromosomal location, and physiological properties of five nuclear genes (BRCA1, DMP1, IRBP, RAG1, vWF) sequenced for this study suggest that these loci are unlinked, exist as single copies, are active in different tissues, and encode protein products with widely divergent functions. All of the sequenced fragments are long (>900 bp), free of ingroup alignment ambiguities, and translate to open reading frame. Nucleotide data from a total of 7320 aligned sites were obtained from 43 ingroup and seven outgroup taxa. Separate parsimony, likelihood, and Bayesian analyses of these six data partitions (morphology + karyotypes, five genes) resulted in highly congruent estimates of didelphid phylogeny with few examples of conflict among strongly supported nodes. Analyses of concatenated sequences and combined (nonmolecular + sequence) datasets effectively summarize all of the common signal recovered from separate analyses: a completely resolved ingroup phylogeny with high support statistics at most nodes. Remaining problems (not conclusively resolved in this study) include the position of the ingroup root and the relationships of three genera (Chacodelphys, Cryptonanus, Tlacuatzin) within their respective suprageneric clades. The history of didelphid classification is reviewed, and all previous systems are found to contain nonmonophyletic groups. A revised phylogenetic classification consistent with our analytic results includes the following higher taxa: Glironiinae (for Glironia), Caluromyinae (Caluromys and Caluromysiops), Hyladelphinae (Hyladelphys), Didelphinae (Marmosini, Metachirini, Didelphini, and Thylamyini), Marmosini (Marmosa, Monodelphis, and Tlacuatzin), Metachirini (Metachirus), Didelphini (Chironectes, Didelphis, Lutreolina, and Philander), and Thylamyini (Chacodelphys, Cryptonanus, Gracilinanus, Lestodelphys, Marmosops, and Thylamys). The probable relationships of several Neogene fossil genera are also discussed. To facilitate identifications, all Recent genera are redescribed, representative crania are illustrated, and a key is provided.Item Phylogenetic relationships of mouse opossums (Didelphidae, Marmosa) with a revised subgeneric classification and notes on sympatric diversity. (American Museum novitates, no. 3817)(American Museum of Natural History., 2014-11-06) Voss, Robert S.; Gutiérrez, Eliécer E.; Solari, Sergio.; Rossi, Rogério V.; Jansa, Sharon A.To resolve phylogenetic relationships among species of Marmosa we analyzed DNA sequences from one mitochondrial and three nuclear genes for every member of the nominotypical subgenus and from four species of the subgenus Micoureus. As reported in previous studies, the subgenus Marmosa was found to be paraphyletic, whereas Micoureus was recovered as a robustly supported clade. Species currently referred to the subgenus Marmosa form four strongly supported and morphologically diagnosable groups. Based on these results we recognize a total of five subgenera: Marmosa Gray, 1821 (for macrotarsus, murina, tyleriana, and waterhousei); Micoureus Lesson, 1842 (for alstoni, constantiae, demerarae, paraguayana, phaea, and regina); Stegomarmosa Pine, 1972 (for andersoni and lepida); Eomarmosa, new subgenus (for rubra); and Exulomarmosa, new subgenus (for isthmica, mexicana, robinsoni, simonsi, xerophila, and zeledoni). The best-supported hypothesis of relationships among these clades is ((Stegomarmosa (Marmosa + Micoureus)) (Eomarmosa + Exulomarmosa)), and our results additionally resolve many interspecific relationships within each subgenus. These clades have broadly overlapping geographic distributions, especially in western Amazonia, where the arboreal insectivorous-frugivorous niche of Marmosa is apparently partitioned among multiple sympatric congeners.Item Phylogenetic relationships of New World porcupines (Rodentia, Erethizontidae) : implications for taxonomy, morphological evolution, and biogeography. (American Museum novitates, no. 3769)(American Museum of Natural History., 2013-02-15) Voss, Robert S.; Hubbard, Caldonia.; Jansa, Sharon A.Phylogenetic analyses of cytochrome-b sequence data from 13 of the 15 currently recognized species of New World porcupines were used to test competing taxonomic hypotheses and to explore scenarios of morphological evolution and biogeography. Consistent with previous studies, the monophyly of Erethizontidae (Chaetomys + Erethizon + Coendou) and the monophyly of Erethizontinae (Erethizon + Coendou) were both strongly supported. However, cytochrome-b sequence data provide no support for the reciprocal monophyly of Coendou, "Echinoprocta," and "Sphiggurus" as those taxa were previously recognized by authors. All of the erethizontid species recognized in recent revisionary work and represented by multiple sequences in this study were recovered as monophyletic groups. Maximum-likelihood (ML) analyses of these data recovered the following phylogeny for 11 species of Coendou: ((melanurus (ichillus (pruinosus + vestitus))) ((spinosus (bicolor + nycthemera)) (prehensilis (mexicanus (quichua + rufescens))))). Ancestral-state reconstructions based on the ML topology suggest that several morphological characters emphasized in past erethizontid classifications (size, nasofrontal sinus inflation, and long fur) have evolved homoplasiously. Maximum-likelihood inference of geographic range evolution suggests that the last common ancestor of living erethizontids was a cis-Andean species, and that most subsequent cladogenesis was also cis-Andean; however, at least two trans-Andean dispersal events are plausibly indicated, as well as two separate invasions of Andean landscapes. Among the most remarkable results of this study are almost-identical sequences of Coendou prehensilis from localities spanning 27° of latitude and 25° of longitude; we speculate that a trophic-niche shift might have allowed rapid range expansion of this species, which accounts for almost all known cases of geographic range overlap and sympatry in the genus Coendou.Item Phylogenetic studies on didelphid marsupials. 2, Nonmolecular data and new IRBP sequences : separate and combined analyses of didelphine relationships with denser taxon sampling. Bulletin of the AMNH ; no. 276(New York, NY : American Museum of Natural History, 2003) Voss, Robert S.; Jansa, Sharon A.In order to test the results of a previous study of didelphid marsupial phylogeny based on IRBP nuclear gene sequences (Jansa and Voss, 2000. Phylogenetic studies on didelphid marsupials I. Introduction and preliminary results from nuclear IRBP gene sequences. Journal of Mammalian Evolution 7: 43-77), we surveyed external, cranial, dental, and karyotypic characters among a more densely taxon-sampled didelphine ingroup. Separate maximum-parsimony analyses of these nonmolecular data and of a new (taxon-dense) IRBP matrix yielded superficially dissimilar strict-consensus topologies. However, no didelphine clade that was even moderately well supported by either separate analysis was contradicted by any equivalently well-supported clade in the other. Instead, all examples of taxonomic incongruence involved weak nodal support from one or both datasets. A maximum-likelihood analysis of the IRBP data produced a consensus topology that was completely congruent with, although slightly more resolved than, the maximum-parsimony consensus. A combined (simultaneous) maximum-parsimony analysis of both datasets (nonmolecular + IRBP) produced a consensus topology that closely resembled the results of analyzing IRBP separately. Most of the didelphine relationships previously reported by Jansa and Voss (op. cit.) are supported by these analytic exercises, with some notable exceptions. The taxon currently known as Marmosa canescens is conspicuously divergent from congeneric species and variously clusters with three different groups ("other Marmosa" + Micoureus, Monodelphis, or higher didelphines (= clade H of Jansa and Voss, op. cit.)) in several parsimony-equivalent resolutions of a fourfold basal polytomy in the IRBP and combined-data consensus topologies. Even without canescens, however, the genus Marmosa is not demonstrably monophyletic. The nomenclatural consequences of these results are discussed, and a new genus is described for "Marmosa" canescens. Future analyses should test the monophyly of other speciose didelphine genera, but new sources of character data will be needed to offset the loss of resolution and decreased nodal support that are often caused by denser taxon sampling.Item A review of the Eliurus tanala complex (Rodentia, Muroidea, Nesomyidae), with description of a new species from dry forests of western Madagascar. (Bulletin of the American Museum of Natural History, no. 430)(American Museum of Natural History., 2019-05-08) Jansa, Sharon A.; Carleton, Michael D.; Soarimalala, Voahangy.; Rakotomalala, Zafimahery.; Goodman, Steven M.Based on 372 specimens examined, we integrated information from two mitochondrial and four nuclear gene sequences, morphological comparisons and morphometric analyses, as well as distributional patterns and ecological occurrences to revise the Eliurus tanala species group (Nesomyinae), a rodent complex endemic to Madagascar’s forests. These evidentiary sources generally proved concordant, supporting description of a new species, E. tsingimbato, indigenous to western dry deciduous forest, mostly associated with limestone karst (tsingy); the two other members of this species group, E. ellermani and E. tanala, are restricted to eastern montane humid forest. Phylogenetic relationships among the three species were poorly resolved, suggesting that their speciation was both recent and rapid. We encountered one instance of conflict between mitochondrial DNA and all other data sources, which we interpret as incomplete lineage sorting involving a population of the new western species. Attention was focused on molecular and morphometric discrimination of the E. tanala and E. antsingy groups where their species distributions overlap in limestone-associated forests of western and northern Madagascar. Phyletic divisions demonstrated within the E. tanala species group are discussed apropos of current models of speciation identified for Malagasy forest-dwelling organisms.Item A revision of Philander (Marsupialia, Didelphidae). Part 1, P. quica, P. canus, and a new species from Amazonia. (American Museum novitates, no. 3891)(American Museum of Natural History., 2018-01-31) Voss, Robert S.; Díaz-Nieto, Juan F.; Jansa, Sharon A.; Angermann, Renate.This is the first installment of a revision of the didelphid marsupial genus Philander, commonly known as gray four-eyed opossums. Although abundant and widespread in lowland tropical forests from southern Mexico to northern Argentina, species of Philander are not well understood taxonomically, and the current literature includes many examples of conflicting species definitions and nomenclatural usage. Our revision is based on coalescent analyses of mitochondrial gene sequences, phylogenetic analyses of mitochondrial and nuclear genes, morphometric analyses, and firsthand examination of relevant type material. Based on these results, we provisionally recognize eight species, of which three are formally treated in this report: P. quica (Temminck, 1824), an Atlantic Forest endemic formerly known as P. frenatus (Olfers, 1818); P. canus (Osgood, 1913), a widespread species formerly treated as a synonym or subspecies of P. opossum (Linnaeus, 1758); and P. pebas, a new species endemic to Amazonia. The remaining, possibly valid, species of Philander can be allocated to two clades. The first is a cis-Andean complex that includes P. andersoni (Osgood, 1913); P. mcilhennyi Gardner and Patton, 1972; and P. opossum. The second is a trans-Andean complex that includes P. melanurus (Thomas, 1899) and P. pallidus (Allen, 1901). Among other nomenclatural acts, we designate a neotype for the long-problematic nominal taxon Didelphis superciliaris Olfers, 1818, and (in an appendix coauthored by Renate Angermann), we establish that Olfers' coeval binomen D. frenata is based on an eastern Amazonian type and is a junior synonym of P. opossum.Item A revision of the didelphid marsupial genus Marmosa. Part 2, Species of the rapposa group (subgenus Micoureus). (Bulletin of the American Museum of Natural History, no. 439)(American Museum of Natural History., 2020-06-01) Voss, Robert S.; Giarla, Thomas C.; Díaz-Nieto, Juan F.; Jansa, Sharon A.In this report, the second of a revisionary series on mouse opossums (Marmosa), we analyze cytochrome b sequence data from 166 specimens of the subgenus Micoureus and delimit putative species using the multirate Poisson Tree Processes (mPTP) method. That analysis identifies 21 putative species, many of which can be matched with available names, including alstoni, constantiae, demerarae, limae, germana, meridae, paraguayana, parda, perplexa, phaea, rapposa, and rutteri. However, some of these nominal taxa are not morphologically diagnosable, and in the absence of other corroborating evidence, we do not recommend that they all be recognized as valid. Phylogenetic analyses of a multigene dataset suggest that putative species of Micoureus belong to several well-supported clades, one of which (the “Rapposa Group”) is revised in this report. As defined herein, the Rapposa Group includes at least three valid species: M. rapposa Thomas, 1899 (including budini Thomas, 1920); M. parda Tate, 1931; and M. rutteri Thomas, 1924. Herein we document their ecogeographic distributions and diagnostic traits, comment on their taxonomic histories, and list the specimens we examined (including all relevant type material).Item A revision of the didelphid marsupial genus Marmosa. Part 4, species of the Alstoni Group (subgenus Micoureus) (American Museum novitates, no. 3983)(American Museum of Natural History., 2021-12-08) Voss, Robert S.; Giarla, Thomas C.; Jansa, Sharon A.In this report, the fourth of a revisionary series on mouse opossums (Marmosa), we treat the members of a monophyletic group of trans-Andean taxa that include M. alstoni (Allen, 1900); M. nicaraguae Thomas, 1905; and M. adleri, a new species. Although cytochrome b sequence divergence values among these species are substantially lower than distances commonly observed among other congeners, members of the Alstoni Group are strikingly unlike one another in morphological traits. We conjecture that rapid phenotypic divergence accompanied the Pleistocene radiation of an ancestral lineage that entered Central America as a late participant in the Great American Biotic Interchange. Additional undescribed species of the Alstoni Group seem likely to exist based on the evidence at hand, and we emphasize the need for renewed collecting in Central America, which has long been neglected by mammalian biodiversity researchers.Item Species limits and phylogenetic relationships in the didelphid marsupial genus Thylamys based on mitochondrial DNA sequences and morphology. (Bulletin of the American Museum of Natural History, no. 346)(American Museum of Natural History., 2010) Giarla, Thomas C.; Voss, Robert S.; Jansa, Sharon A.Species of the didelphid marsupial genus Thylamys, commonly known as fat-tailed mouse opossums, are broadly distributed in the open habitats of central and southern South America. In this report we examine species limits in the genus and infer phylogenetic relationships among Thylamys species using both molecular phylogenetic and morphological methods. We assessed species limits using a broad geographic sample of DNA sequences from the mitochondrial gene cytochrome b in conjunction with morphological character analysis, and we inferred phylogenetic relationships among species using the cytochrome-b dataset in addition to sequences from the mitochondrial genes cytochrome c oxidase subunit II and NADH dehydrogenase 2 for a representative subset of individuals. Based on the results of these analyses, we recognize Xerodelphys (new subgenus) for T. karimii and T. velutinus, and we recognize seven valid species in the nominotypical subgenus. The latter includes T. macrurus, T. pusillus, and two monophyletic species groups: the Elegans Group (T. elegans, T. pallidior, T. tatei) and the Venustus Group (T. sponsorius, T. venustus). Analysis of cytochrome-b sequences additionally reveals deep phylogeographic structuring in three species (T. pallidior, T. pusillus, T. venustus), each of which contains two or three robustly supported allopatric haplogroups. The existence of undescribed Peruvian forms of the Elegans Group is also plausibly indicated. We provide morphological diagnoses of all species recognized as valid in this report, summarize information about geographic distributions, comment on previous misidentifications, and briefly consider historical-biogeographic scenarios with a focus on dispersal events across the Andes.Item Supplemental Material for 'Craniodental morphology and phylogeny of marsupials (Bulletin of the American Museum of Natural History, no. 457)'(New York, NY : American Museum of Natural History, 2022-06-28) Beck, Robin M. D.; Voss, Robert S.; Jansa, Sharon A.Supplemental Material for 'Craniodental morphology and phylogeny of marsupials (Bulletin of the American Museum of Natural History, no. 457) - https://digitallibrary.amnh.org/handle/2246/7298Item Systematic mammalogy : contributions in honor of Guy G. Musser. (Bulletin of the American Museum of Natural History, no. 331)(New York : American Museum of Natural History., 2009) Voss, Robert S.; Carleton, Michael D.; Anderson, Robert P.; Gutiérrez, Eliécer E.; Arroyo-Cabrales, Joaquín.; Flynn, Lawrence J. (Lawrence John), 1932-; Gardner, Alfred L.; Giannini, Norberto P.; Almeida, Francisca Cunha.; Simmons, Nancy B.; Heaney, Lawrence R.; Balete, Danilo S., 1960-; Rickart, Eric A.; Veluz, M. Josefa.; Jansa, Sharon A.; Helgen, K. M. (Kristofer M.); Helgen, Lauren E.; Holden, Mary Ellen.; Levine, Rebecca S.; Jenkins, Paulina D.; Lunde, Darrin P.; Moncrieff, Clive B.; Myers, Philip, 1947-; Catzeflis, François.; Carmignotto, Ana Paula.; Barreiro Rodríguez, Josefina.; Wahlert, John H.; Musser, Guy G.Contents: They sort out like nuts and bolts : a scientific biography of Guy G. Musser / Michael D. Carleton -- Taxonomy, distribution, and natural history of the genus Heteromys (Rodentia: Heteromyidae) in central and eastern Venezuela, with the description of a new species from the Cordillera de la Costa / Robert P. Anderson and Eliécer E. Gutiérrez -- Review of the Oryzomys couesi complex (Rodentia: Cricetidae: Sigmodontinae) in western Mexico / Michael D. Carleton and Joaquin Arroyo-Cabrales -- The antiquity of Rhizomys and independent acquisition of fossorial traits in subterranean muroids / Lawrence J. Flynn -- A new species of Reithrodontomys, subgenus Aporodon (Cricetidae: Neotominae), from the highlands of Costa Rica, with comments on Costa Rican and Panamanian Reithrodontomys / Alfred L. Gardner and Michael D. Carleton -- Phylogenetic relationships of harpyionycterine megabats (Chiroptera: Pteropodidae) / Norberto P. Giannini, Francisca Cunha Almeida, and Nancy B. Simmons -- A new genus and species of small "tree-mouse" (Rodentia, Muridae) related to the Philippine giant cloud rats / Lawrence R. Heaney, Danilo S. Balete, Eric A. Rickart, M. Josefa Veluz, and Sharon A. Jansa -- Biodiversity and biogeography of the moss-mice of New Guinea : a taxonomic revision of Pseudohydromys (Muridae: Murinae) / Kristofer M. Helgen and Lauren E. Helgen -- Systematic revision of sub-Saharan African dormice (Rodentia: Gliridae). Part 2, Description of a new species of Graphiurus from the central Congo Basin, including morphological and ecological niche comparisons with G. crassicaudatus and G. lorraineus / Mary Ellen Holden and Rebecca S. Levine -- Descriptions of new species of Crocidura (Soricomorpha: Soricidae) from mainland Southeast Asia, with synopses of previously described species and remarks on biogeography / Paulina D. Jenkins, Darrin P. Lunde, and Clive B. Moncrieff -- The six opossums of Félix de Azara : identification, taxonomic history, neotype designations, and nomenclatural recommendations / Robert S. Voss, Philip Myers, François Catzeflis, Ana Paula Carmignotto, and Josefina Barreiro -- Skull and dentition of Willeumys korthi, nov. gen. et sp., a cricetid rodent from the Oligocene (Orellan) of Wyoming / John H. Wahlert.Item Three new species of Musseromys (Muridae, Rodentia), the endemic Philippine tree mouse from Luzon Island. (American Museum novitates, no. 3802)(American Museum of Natural History., 2014-05-16) Heaney, Lawrence R.; Balete, Danilo S., 1960-; Rickart, Eric A.; Veluz, M. Josefa (Maria Josefa); Jansa, Sharon A.We describe and name three new species of Musseromys from the mountains of northern Luzon based on morphological and DNA sequence data. Previously, Musseromys was known only from one species from the lowlands of central Luzon. These are the smallest-known members of the cloud rat clade of endemic Philippine murids, weighing only 15-22 g, an order of magnitude smaller than the previously smallest known members of the clade (Carpomys spp.), and more than two orders of magnitude smaller than the largest members (Phloeomys spp.). These discoveries raise the number of native murids documented on Luzon to 43, 93% of which are endemic, and 88% of which are members of two endemic Philippine clades. Musseromys is inferred to have originated in montane habitats, probably in the Central Cordillera of northern Luzon, with movement to two other areas on Luzon, one in montane habitat and one in lowland habitat, associated with the speciation process.