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Sharon A Jansa - One of the best experts on this subject based on the ideXlab platform.
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tempo and mode of mandibular shape and size evolution reveal mixed support for incumbency effects in two clades of island endemic rodents muridae Murinae
Evolution, 2019Co-Authors: Sharon A Jansa, Lawrence R Heaney, Dakota M RowseyAbstract:Existing radiations in a spatially limited system such as an oceanic island may limit the ecological opportunity experienced by later colonists, resulting in lower macroevolutionary rates for secondary radiations. Additionally, potential colonists may be competitively excluded by these incumbent (resident) species, unless they are biologically distinct (biotic filtering). The extant phenotypic diversity of secondary colonists may thus be impacted by lower rates of phenotypic evolution, exclusion from certain phenotypes, and transitions to new morphotypes to escape competition from incumbent lineages. We used geometric morphometric methods to test whether the rates and patterns of mandibular evolution of the Luzon "old endemic" rodent clades, Phloeomyini and Chrotomyini, are consistent with these predictions. Each clade occupied nearly completely separate shape space and partially separate size space. We detected limited support for decelerating and clade-specific evolutionary rates for both shape and size, with strong evidence for a shift in evolutionary mode within Chrotomyini. Our results suggest that decelerating phenotypic evolutionary rates are not a necessary result of incumbency interactions; rather, incumbency effects may be more likely to determine which clades can become established in the system. Nonincumbent clades that pass a biotic filter can potentially exhibit relatively unfettered evolution.
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archboldomys muridae Murinae reconsidered a new genus and three new species of shrew mice from luzon island philippines
American Museum Novitates, 2012Co-Authors: Danilo S Balete, Eric A Rickart, Lawrence R Heaney, Phillip A Alviola, Melizar V Duya, Timothy Sosa, Sharon A JansaAbstract:ABSTRACT 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 follo...
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descriptions of two new species of rhynchomys thomas rodentia muridae Murinae from luzon island philippines
Journal of Mammalogy, 2007Co-Authors: Danilo S Balete, Eric A Rickart, Ruth Grace Rosellambal, Sharon A Jansa, Lawrence R HeaneyAbstract:Rhynchomys belongs to a unique assemblage of Philippine rodents that exhibit a combination of primitive features as well as unique morphological specializations. These nocturnal “shrew-rats,” with highly specialized vermivorous and insectivorous food habits, are endemic to Luzon Island. Analyses of external, cranial, and dental features support the recognition of 4 species, 2 of which are described in this paper. All are restricted to high-elevation habitats, about 1,100 m and above, in montane and mossy forest on northern, western, and southeastern Luzon. Habitat vicariance and subsequent divergence in isolation is the probable mode of diversification in Rhynchomys as well as in other murid clades whose members are restricted to high-elevation habitats. The discovery of locally endemic species of Rhynchomys both confirms the existence of multiple centers of endemism on Luzon and underscores the need to establish and maintain additional protected areas on the island.
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the pattern and timing of diversification of philippine endemic rodents evidence from mitochondrial and nuclear gene sequences
Systematic Biology, 2006Co-Authors: Sharon A Jansa, Keith F Barker, Lawrence R HeaneyAbstract:The 22 genera and 64 species of rodents (Muridae: Murinae) distributed in the Philippine Islands provide a unique opportunity to study patterns and processes of diversification in island systems. Over 90% of these rodent species are endemic to the archipelago, but the relative importance of dispersal from the mainland, dispersal within the archipelago, and in situ differentiation as explanations of this diversity remains unclear, as no phylogenetic hypothesis for these species and relevant mainland forms is currently available. Here we report the results of phylogenetic analyses of the endemic Philippine murines and a wide sampling of murine diversity from outside the archipelago, based on the mitochondrial cytochrome b gene and the nuclear-encoded IRBP exon 1. Analysis of our combined gene data set consistently identified five clades comprising endemic Philippine genera, suggesting multiple invasions of the archipelago. Molecular dating analyses using parametric and semiparametric methods suggest that colonization occurred in at least two stages, one ca. 15 Mya, and another 8 to 12 million years later, consistent with the previous recognition of "Old" and "New" endemic rodent faunas. Ancestral area analysis suggests that the Old Endemics invaded landmasses that are now part of the island of Luzon, whereas the three New Endemic clades may have colonized through either Mindanao, Luzon, or both. Further, our results suggest that most of the diversification of Philippine murines took place within the archipelago. Despite heterogeneity between nuclear and mitochondrial genes in most model parameters, combined analysis of the two data sets using both parsimony and likelihood increased phylogenetic resolution; however, the effect of data combination on support for resolved nodes was method dependent. In contrast, our results suggest that combination of mitochondrial and nuclear data to estimate relatively ancient divergence times can severely compromise those estimates, even when specific methods that account for rate heterogeneity among genes are employed. (Biogeography; divergence date estimation; mitochondrial DNA; molecular systematics; Murinae; nuclear exon; Philippines; phylogeny.) Studies of diversification in island archipelagos have held a central place in evolutionary biology for over
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phylogeny of muroid rodents relationships within and among major lineages as determined by irbp gene sequences
Molecular Phylogenetics and Evolution, 2004Co-Authors: Sharon A Jansa, Marcelo WekslerAbstract:The rodent family Muridae is the single most diverse family of mammals with over 1300 recognized species. We used DNA sequences from the first exon (∼1200 bp) of the IRBP gene to infer phylogenetic relationships within and among the major lineages of muroid rodents. We included sequences from every recognized muroid subfamily except Platacanthomyinae and from all genera within the endemic Malagasy subfamily Nesomyinae, all recognized tribes of Sigmodontinae, and a broad sample of genera in Murinae. Phylogenetic analysis of the IRBP data suggest that muroid rodents can be sorted into five major lineages: (1) a basal clade containing the fossorial rodents in the subfamilies Spalacinae, Myospalacinae, and Rhizomyinae, (2) a clade of African and Malagasy genera comprising the subfamilies Petromyscinae, Mystromyinae, Cricetomyinae, Nesomyinae, and core dendromurines, (3) a clade of Old World taxa belonging to Murinae, Otomyinae, Gerbillinae, Acomyinae, and Lophiomyinae, (4) a clade uniting the subfamilies Sigmodontinae, Arvicolinae, and Cricetinae, and (5) a unique lineage containing the monotypic Calomyscinae. Although relationships among the latter four clades cannot be resolved, several well-supported supergeneric groupings within each are identified. A preliminary examination of molar tooth morphology on the resulting phylogeny suggests the triserial murid molar pattern as conceived by Simpson (1945) evolved at least three times during the course of muroid evolution.
Pascale Chevret - One of the best experts on this subject based on the ideXlab platform.
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phylogeny and biogeography of african Murinae based on mitochondrial and nuclear gene sequences with a new tribal classification of the subfamily
BMC Evolutionary Biology, 2008Co-Authors: Pascale Chevret, Francois Catzeflis, Emilie Lecompte, Christiane Denys, Ken Aplin, Marion ChadesAbstract:Within the subfamily Murinae, African murines represent 25% of species biodiversity, making this group ideal for detailed studies of the patterns and timing of diversification of the African endemic fauna and its relationships with Asia. Here we report the results of phylogenetic analyses of the endemic African murines through a broad sampling of murine diversity from all their distribution area, based on the mitochondrial cytochrome b gene and the two nuclear gene fragments (IRBP exon 1 and GHR). A combined analysis of one mitochondrial and two nuclear gene sequences consistently identified and robustly supported ten primary lineages within Murinae. We propose to formalize a new tribal arrangement within the Murinae that reflects this phylogeny. The diverse African murine assemblage includes members of five of the ten tribes and clearly derives from multiple faunal exchanges between Africa and Eurasia. Molecular dating analyses using a relaxed Bayesian molecular clock put the first colonization of Africa around 11 Mya, which is consistent with the fossil record. The main period of African murine diversification occurred later following disruption of the migration route between Africa and Asia about 7–9 Mya. A second period of interchange, dating to around 5–6.5 Mya, saw the arrival in Africa of Mus (leading to the speciose endemic Nannomys), and explains the appearance of several distinctive African lineages in the late Miocene and Pliocene fossil record of Eurasia. Our molecular survey of Murinae, which includes the most complete sampling so far of African taxa, indicates that there were at least four separate radiations within the African region, as well as several phases of dispersal between Asia and Africa during the last 12 My. We also reconstruct the phylogenetic structure of the Murinae, and propose a new classification at tribal level for this traditionally problematic group.
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morphological diversity of old world rats and mice rodentia muridae mandible in relation with phylogeny and adaptation
Journal of Zoological Systematics and Evolutionary Research, 2007Co-Authors: Jacques Michaux, Pascale Chevret, Sabrina RenaudAbstract:The respective roles of the phylogenetic and ecological components in an adaptive radiation are tested on a sample of Old World rats and mice (Muridae, Murinae). Phylogeny was established on nuclear and mitochondrial genes and reconstructed by maximum likelihood and Bayesian methods. This phylogeny is congruent with previous larger scale ones recently published, but includes some new results: Bandicota and Nesokia are sister taxa and Micromys would be closely related to the Rattus group. The ecological diversification is investigated through one factor, the diet, and the mandible outline provides the morphological marker. Elliptic and radial Fourier transforms are used for quantifying size and shape differences among species. Univariate size and shape parameters indicate that phylogeny is more influential on size than diet, and the reverse occurs for shape and robust patterns are recognized by multivariate analyses of the data sets provided by the Fourier methods. Omnivorous and herbivorous groups are well separated despite some overlapping, as well as are other Murinae with a specialized diet (insects, seeds). Phylogeny is also influential as shown by the segregation of several groups (Praomys, Arvicanthini, Rattus, Apodemus). Allometric shape variation was investigated, and although present it does not overwhelm effects of either phylogeny or diet. Massive mandibles characterize herbivorous Murinae and slender mandibles, the insectivorous ones. A strong angular process relative to the coronoid process characterizes seedeaters, and the reverse characterized Murinae with a diet based largely on animal matter. Such changes in morphology are clearly in relation with the functioning of the mandible, and with the forces required by the nature of the food: the need of a stronger occlusal force in herbivorous species would explain massive mandibles, and an increase of the grasping and piercing function of incisors in insectivorous species would explain slender mandibles. Resume L’etude a pour but de reconnaitre le role respectif de la parente et de l’ecologie lors d'une radiation adaptative en prenant l'exemple des rats et souris de l'Ancien Monde (Muridae, Murinae). Des genes nucleaires et mitochondriaux fournissent une phylogenie construite a partir des methodes du maximum de vraisemblance et de Mr Bayes. La phylogenie obtenue est congruente avec les phylogenie recemment publiees sur des echantillons plus nombreux de taxons, mais inclut quelques resultats nouveaux: Bandicota et Nesokia sont des taxons freres et Micromys serait etroitement apparente au groupe Rattus. Le regime alimentaire fournit le critere de separation ecologique et le contour de la mandibule en est le marqueur morphologique. La quantification de la taille et de la forme resulte de l'application des transformees de Fourier, radiale et elliptique, aux contours de la mandibule. Si un effet de la parente se degage des indicateurs univaries de taille, l'adaptation au regime alimentaire ressort des indicateurs de forme. Les analyses multivariees appliquees aux ensembles de coefficients de Fourier fournis par les methodes utilisees revelent des motifs robustes dans la distribution des taxons. Ainsi, les taxons omnivores et herbivores sont bien separes malgre un certain chevauchement, il en est de meme des autres Murinae avec un regime specialise (insectes, graines). La phylogenie a egalement une influence sur la distribution des taxons comme l'indique la segregation de plusieurs groupes (Praomys, Arvicanthini, Rattus, Apodemus). S'il y a une variation allometrique de la forme en fonction de la taille, celle-ci ne masque ni la parente ni l'adaptation. Une mandibule massive caracterise les Murinae herbivores et une mandibule gracile, celle des insectivores. Un processus angulaire fort par rapport au processus coronoide caracterise les granivores, et l'inverse caracterise les Murinae avec un regime base en grande partie sur une nourriture animale. Les differences de la forme de la mandibule sont clairement en rapport avec son fonctionnement et la nature des aliments. Chez un herbivore, la force a exercer au niveau des molaires est plus grande que chez un omnivore, ce qui expliquerait la massivite de la mandibule, chez un insectivore, l'allongement de la mandibule renvoie au role des incisives qui pincent et percent.
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molecular phylogeny of the praomys complex rodentia Murinae a study based on dna dna hybridization experiments
Zoological Journal of the Linnean Society, 1994Co-Authors: Pascale Chevret, Jean-marc Duplantier, Laurent Granjon, Christiane Denys, Francois CatzeflisAbstract:Abstract Within the Murinae (Muridae: Rodentia), the African rats of the Praomys group, whose systematics has been studied through different approaches, have raised numerous taxonomic problems. Different taxa related to Praomys have successively been described, among which Mastomys, Myomys and Hylomyscus were considered either as separate genera or subgenera of Praomys . In order to clarify the relationships within the Praomys group, we conducted a series of DNA/DNA hybridization experiments involving different species of Praomys, Mastomys, Myomys and Hylomyscus plus other Murinae and a Cricetomyinae. This study indicates that the Praomys complex is a monophyletic entity clearly separated from the other African and Asian Murinae. If Mastomys and Hylomyscus appeared to be independent genera, the taxonomic situation of Praomys and Myomys is more difficult to ascertain. Indeed, Praomy tullbergi appears more closely related to Myomys daltoni than to another species of Praomys , namely P. jacksoni , suggesting paraphyly for Praomys . Furthermore, P. jacksoni is as distant from P. tullbergi as from any species of Mastomys . Additional species of Praomys and, especially, of Myomys , are needed for reaching a definitive conclusion on these latter taxa. The Praomys group is more related to Mus than to Rattus . To calibrate our molecular distances with geological time, we used a dating of 10 Myr for the Mus/Rattus dichotomy. The inferred rate of molecular evolution suggests a dating of c. 8 Myr for the separation of the Praomys group from the Mus lineage.
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etude evolutive des Murinae rongeurs mammiferes africains par hybridations adn adn comparaisons avec les approches morphologiques et paleontologiques
1994Co-Authors: Pascale ChevretAbstract:L'histoire evolutive des Murinae (rodentia: muroidea) commence il y a environ 15 ma avec le genre fossile antemus et montre une tres grande diversification avec deux zones de fort endemisme: l'asie du sud-est et l'afrique. Parmi les genres de Murinae actuels, 24 ont ete inclus dans cette etude, ainsi que des genres appartenant a d'autres sous-familles de muridae: dendroMurinae, gerbillinae, otomyinae et cricetomyinae. L'approche utilisee est celle des hybridations adn/adn. Les resultats des experiences d'hybridation adn/adn ont ete confrontes aux donnees morphologiques et paleontologiques disponibles, ainsi qu'aux resultats d'autres approches biochimiques et moleculaires. Acomys, uranomys et lophyromys sont exclus des Murinae. Les Murinae se separent en trois ensembles, l'un contenant en l'etat actuel de nos donnees un seul genre: micromys ; le deuxieme contenant le genre rattus et les genres asiatiques qui lui sont proches ; le dernier contenant mus, apodemus, millardia otomys et tous les Murinae africains etudies. Les resultats des hybridations adn/adn indiquent que la radiation des Murinae en afrique se serait faite a partir d'au moins trois vagues issues d'asie, arrivees en afrique il y a au moins 5 ma. Celles-ci ont donne naissance respectivement au groupe praomys, au groupe arvicanthis et a nannomys. Cette etude pose le probleme de la definition et/ou du contenu des otomyinae, car otomys est inclus dans les Murinae, des dendroMurinae, car deomys et steatomys ne sont pas monophyletiques, et des Murinae. Au sein des muridae, les Murinae sont plus proche des gerbillinae que des cricetomyinae
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molecular evidence that the spiny mouse acomys is more closely related to gerbils gerbillinae than to true mice Murinae
Proceedings of the National Academy of Sciences of the United States of America, 1993Co-Authors: Pascale Chevret, Jacques Michaux, Christiane Denys, Jeanjacques Jaeger, Francois CatzeflisAbstract:Spiny mice of the genus Acomys traditionally have been classified as members of the Murinae, a subfamily of rodents that also includes rats and mice with which spiny mice share a complex set of morphological characters, including a unique molar pattern. The origin and evolution of this molar pattern, documented by many fossils from Southern Asia, support the hypothesis of the monophyly of Acomys and all other Murinae. This view has been challenged by immunological studies that have suggested that Acomys is as distantly related to mice (Mus) as are other subfamilies (e.g., hamsters: Cricetinae) of the muroid rodents. We present molecular evidence derived from DNA.DNA hybridization data that indicate that the spiny mouse Acomys and two African genera of Murinae, Uranomys and Lophuromys, constitute a monophyletic clade, a view that was recently suggested on the basis of dental characters. However, our DNA.DNA hybridization data also indicate that the spiny mice (Acomys) are more closely related to gerbils (Gerbillinae) than to the true mice and rats (Murinae) with which they have been classified. Because Acomys and the brush-furred mice Uranomys and Lophuromys share no derived morphological characters with the Gerbillinae, their murine morphology must have evolved by convergence, including the molar pattern previously considered to support the monophyly of the Murinae.
Guy G Musser - One of the best experts on this subject based on the ideXlab platform.
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a systematic review of sulawesi bunomys muridae Murinae with the description of two new species
Bulletin of the American Museum of Natural History, 2014Co-Authors: Guy G MusserAbstract: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 mon...
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a new genus of rodent from wallacea rodentia muridae Murinae rattini and its implication for biogeography and indo pacific rattini systematics
Zoological Journal of the Linnean Society, 2013Co-Authors: Pierre-henri Fabre, Marie Pagès, Guy G Musser, Yuli Sulistya Fitriana, Jon Fjeldsa, Andrew P Jennings, Knud A Jonsson, Jonathan D Kennedy, Johan MichauxAbstract:We describe Halmaheramys bokimekot Fabre, Pages, Musser, Fitriana, Semiadi & Helgen gen. et sp. nov., a new genus and species of murine rodent from the North Moluccas, and study its phylogenetic placement using both molecular and morphological data. We generated a densely sampled mitochondrial and nuclear DNA data set that included most genera of Indo-Pacific Murinae, and used probabilistic methodologies to infer their phylogenetic relationships. To reconstruct their biogeographical history, we first dated the topology and then used a Lagrange analysis to infer ancestral geographic areas. Finally, we combined the ancestral area reconstructions with temporal information to compare patterns of murine colonization among Indo-Pacific archipelagos. We provide a new and comprehensive molecular phylogenetic reconstruction for Indo-Pacific Murinae, with a focus on the Rattus division. Using previous results and those presented in this study, we define a new Indo-Pacific group within the Rattus division, composed of Bullimus, Bunomys, Paruromys, Halmaheramys, Sundamys, and Taeromys. Our phylogenetic reconstructions revealed a relatively recent diversification from the Middle Miocene to Plio-Pleistocene associated with several major dispersal events. We identified two independent Indo-Pacific dispersal events from both western and eastern Indo-Pacific archipelagos to the isolated island of Halmahera, which led to the speciations of H. bokimekot gen. et sp. nov. and Rattus morotaiensis Kellogg, 1945. We propose that a Middle Miocene collision between the Halmahera and Sangihe arcs may have been responsible for the arrival of the ancestor of Halmaheramys to eastern Wallacea. Halmaheramys bokimekot gen. et sp. nov. is described in detail, and its systematics and biogeography are documented and illustrated. © 2013 The Linnean Society of London
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systematic reviews of new guinea coccymys and melomys albidens muridae Murinae with descriptions of new taxa
Bulletin of the American Museum of Natural History, 2009Co-Authors: Guy G Musser, Darrin P LundeAbstract: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 Smith's 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 restr...
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systematic reviews of new guinea coccymys and melomys albidens muridae Murinae with descriptions of new taxa bulletin of the american museum of natural history no 329
2009Co-Authors: Guy G Musser, Darrin P LundeAbstract:139 p. : ill. (some col.), maps ; 26 cm. "Issued December 9, 2009." Some specimens of Coccymys collected during the fourth Archbold Expedition to New Guinea (1953). Includes bibliographical references (p. 135-139).
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systematic review of new guinea leptomys muridae Murinae with descriptions of two new species
American Museum Novitates, 2008Co-Authors: Guy G Musser, Kristofer M Helgen, Darrin P LundeAbstract:Abstract Two new species of the endemic New Guinea rodent genus Leptomys Thomas, 1897, are described: L. paulus, indigenous to the montane forests in the Owen Stanley Range in eastern New Guinea, and L. arfakensis, known only from the Arfak Mountains on the Vogelkop Peninsula in western New Guinea. These descriptions are presented within a taxonomic review of Leptomys based on all known specimens in collections of the world's museums. In addition to the new species, the morphological attributes and geographic distributions of three others are documented. Leptomys elegans occurs in southcentral and southeastern New Guinea both north and south of the Central Cordillera, ranging from the Kikori River Basin in the west to the southern slopes of the Owen Stanley Range, then extending round to the north side of the Cordillera in the Maneau Range, and in the outlying highland block of Mount Victory. Leptomys signatus is recorded only from the Fly and Kikori River drainages south of the Central Cordillera. Leptom...
Peter J. Taylor - One of the best experts on this subject based on the ideXlab platform.
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Associated tympanic bullar and cochlear hypertrophy define adaptations to true deserts in African gerbils and laminate-toothed rats (Muridae: Gerbillinae and Murinae)
Journal of Anatomy, 2019Co-Authors: Aluwani Nengovhela, Christiane Denys, José Braga, Frikkie De Beer, Christophe Tenailleau, Peter J. TaylorAbstract:Hearing capabilities in desert rodents such as gerbils and heteromyids have been inferred from both anatomical and ecological aspects and tested with experiments and theoretical models. However, very few studies have focused on other desert‐adapted species. In this study, a refined three‐dimensional morphometric approach was used on three African rodent tribes (Otomyini, Taterillini and Gerbillini) to describe the cochlear and tympanic bullar morphology, and to explore the role of phylogeny, allometry and ecology to better understand the underlying mechanism of any observed trends of hypertrophy in the bulla and associated changes in the cochlea. As a result, desert‐adapted species could be distinguished from mesic and semi‐arid taxa by the gross cochlear dimensions, particularly the oval window, which is larger in desert species. Bullar and cochlear modifications between species could be explained by environment (bulla and oval window), phylogeny (cochlear curvature gradient) and/or allometry (cochlear relative length, oval window and bulla) with some exceptions. Based on their ear anatomy, we predict that Desmodillus auricularis and Parotomys brantsii should be sensitive to low‐frequency sounds, with D. auricularis sensitive to high‐frequency sounds, too. This study concludes that in both arid and semi‐arid adapted laminate‐toothed rats and gerbils there is bulla and associated cochlea hypertrophy, particularly in true desert species. Gerbils also show tightly coiled cochlea but the significance of this is debatable and may have nothing to do with adaptations to any specific acoustics in the desert environment.
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specific limits and emerging diversity patterns in east african populations of laminate toothed rats genus otomys muridae Murinae otomyini revision of the otomys typus complex
Zootaxa, 2011Co-Authors: Peter J. Taylor, Erik Verheyen, L A Lavrenchenko, Michael D Carleton, Nigel C Bennett, Carel J Oosthuizen, Sarita MareeAbstract:We gratefully acknowledge the financial assistance of the Smithsonian Institution Short Term Visitor Award (in 2006), and a South African National Research Foundation Grant (between 2005 and 2007), which allowed P.J.T. to visit and study important North American and European museum collections of Otomys.
Christiane Denys - One of the best experts on this subject based on the ideXlab platform.
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Associated tympanic bullar and cochlear hypertrophy define adaptations to true deserts in African gerbils and laminate-toothed rats (Muridae: Gerbillinae and Murinae)
Journal of Anatomy, 2019Co-Authors: Aluwani Nengovhela, Christiane Denys, José Braga, Frikkie De Beer, Christophe Tenailleau, Peter J. TaylorAbstract:Hearing capabilities in desert rodents such as gerbils and heteromyids have been inferred from both anatomical and ecological aspects and tested with experiments and theoretical models. However, very few studies have focused on other desert‐adapted species. In this study, a refined three‐dimensional morphometric approach was used on three African rodent tribes (Otomyini, Taterillini and Gerbillini) to describe the cochlear and tympanic bullar morphology, and to explore the role of phylogeny, allometry and ecology to better understand the underlying mechanism of any observed trends of hypertrophy in the bulla and associated changes in the cochlea. As a result, desert‐adapted species could be distinguished from mesic and semi‐arid taxa by the gross cochlear dimensions, particularly the oval window, which is larger in desert species. Bullar and cochlear modifications between species could be explained by environment (bulla and oval window), phylogeny (cochlear curvature gradient) and/or allometry (cochlear relative length, oval window and bulla) with some exceptions. Based on their ear anatomy, we predict that Desmodillus auricularis and Parotomys brantsii should be sensitive to low‐frequency sounds, with D. auricularis sensitive to high‐frequency sounds, too. This study concludes that in both arid and semi‐arid adapted laminate‐toothed rats and gerbils there is bulla and associated cochlea hypertrophy, particularly in true desert species. Gerbils also show tightly coiled cochlea but the significance of this is debatable and may have nothing to do with adaptations to any specific acoustics in the desert environment.
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phylogeny and biogeography of african Murinae based on mitochondrial and nuclear gene sequences with a new tribal classification of the subfamily
BMC Evolutionary Biology, 2008Co-Authors: Pascale Chevret, Francois Catzeflis, Emilie Lecompte, Christiane Denys, Ken Aplin, Marion ChadesAbstract:Within the subfamily Murinae, African murines represent 25% of species biodiversity, making this group ideal for detailed studies of the patterns and timing of diversification of the African endemic fauna and its relationships with Asia. Here we report the results of phylogenetic analyses of the endemic African murines through a broad sampling of murine diversity from all their distribution area, based on the mitochondrial cytochrome b gene and the two nuclear gene fragments (IRBP exon 1 and GHR). A combined analysis of one mitochondrial and two nuclear gene sequences consistently identified and robustly supported ten primary lineages within Murinae. We propose to formalize a new tribal arrangement within the Murinae that reflects this phylogeny. The diverse African murine assemblage includes members of five of the ten tribes and clearly derives from multiple faunal exchanges between Africa and Eurasia. Molecular dating analyses using a relaxed Bayesian molecular clock put the first colonization of Africa around 11 Mya, which is consistent with the fossil record. The main period of African murine diversification occurred later following disruption of the migration route between Africa and Asia about 7–9 Mya. A second period of interchange, dating to around 5–6.5 Mya, saw the arrival in Africa of Mus (leading to the speciose endemic Nannomys), and explains the appearance of several distinctive African lineages in the late Miocene and Pliocene fossil record of Eurasia. Our molecular survey of Murinae, which includes the most complete sampling so far of African taxa, indicates that there were at least four separate radiations within the African region, as well as several phases of dispersal between Asia and Africa during the last 12 My. We also reconstruct the phylogenetic structure of the Murinae, and propose a new classification at tribal level for this traditionally problematic group.
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the phylogeny of the praomys complex rodentia muridae and its phylogeographic implications
Journal of Zoological Systematics and Evolutionary Research, 2002Co-Authors: Emilie Lecompte, Christiane DenysAbstract:Among the African Murinae (Rodentia, Muridae), the Praomys complex, whose systematics has been studied by different approaches, has raised numerous taxonomic problems. Different taxa, namely Praomys, Mastomys, Myomys and Hylomyscus have been considered either as separate genera or subgenera of Praomys. In order to understand the relationships within the Praomys complex and to test the monophyly of the genus Praomys, a cladistic analysis was conducted, based on morpho-anatomical factors involving different species of Praomys, Mastomys, Myomys and Hylomyscus. The results indicate that the Praomys complex is monophyletic, as are the genera Hylomyscus, Mastomys and Myomys, whereas the genus Praomys appears paraphyletic. Indeed, a group of species including Praomys jacksoni was found to be more closely related to the genera Mastomys and Myomys than to a Praomys tullbergi-group. The biotopes and the distribution areas of the species were mapped on the phylogeny. It appears that the different clades each present a relative ecological cohesion and are arranged according to a gradient from closed to open habitats. From there, an evolutionary scenario is proposed for the emergence of the different clades and species of the genus Praomys sensu stricto.
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molecular phylogeny of the praomys complex rodentia Murinae a study based on dna dna hybridization experiments
Zoological Journal of the Linnean Society, 1994Co-Authors: Pascale Chevret, Jean-marc Duplantier, Laurent Granjon, Christiane Denys, Francois CatzeflisAbstract:Abstract Within the Murinae (Muridae: Rodentia), the African rats of the Praomys group, whose systematics has been studied through different approaches, have raised numerous taxonomic problems. Different taxa related to Praomys have successively been described, among which Mastomys, Myomys and Hylomyscus were considered either as separate genera or subgenera of Praomys . In order to clarify the relationships within the Praomys group, we conducted a series of DNA/DNA hybridization experiments involving different species of Praomys, Mastomys, Myomys and Hylomyscus plus other Murinae and a Cricetomyinae. This study indicates that the Praomys complex is a monophyletic entity clearly separated from the other African and Asian Murinae. If Mastomys and Hylomyscus appeared to be independent genera, the taxonomic situation of Praomys and Myomys is more difficult to ascertain. Indeed, Praomy tullbergi appears more closely related to Myomys daltoni than to another species of Praomys , namely P. jacksoni , suggesting paraphyly for Praomys . Furthermore, P. jacksoni is as distant from P. tullbergi as from any species of Mastomys . Additional species of Praomys and, especially, of Myomys , are needed for reaching a definitive conclusion on these latter taxa. The Praomys group is more related to Mus than to Rattus . To calibrate our molecular distances with geological time, we used a dating of 10 Myr for the Mus/Rattus dichotomy. The inferred rate of molecular evolution suggests a dating of c. 8 Myr for the separation of the Praomys group from the Mus lineage.
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molecular evidence that the spiny mouse acomys is more closely related to gerbils gerbillinae than to true mice Murinae
Proceedings of the National Academy of Sciences of the United States of America, 1993Co-Authors: Pascale Chevret, Jacques Michaux, Christiane Denys, Jeanjacques Jaeger, Francois CatzeflisAbstract:Spiny mice of the genus Acomys traditionally have been classified as members of the Murinae, a subfamily of rodents that also includes rats and mice with which spiny mice share a complex set of morphological characters, including a unique molar pattern. The origin and evolution of this molar pattern, documented by many fossils from Southern Asia, support the hypothesis of the monophyly of Acomys and all other Murinae. This view has been challenged by immunological studies that have suggested that Acomys is as distantly related to mice (Mus) as are other subfamilies (e.g., hamsters: Cricetinae) of the muroid rodents. We present molecular evidence derived from DNA.DNA hybridization data that indicate that the spiny mouse Acomys and two African genera of Murinae, Uranomys and Lophuromys, constitute a monophyletic clade, a view that was recently suggested on the basis of dental characters. However, our DNA.DNA hybridization data also indicate that the spiny mice (Acomys) are more closely related to gerbils (Gerbillinae) than to the true mice and rats (Murinae) with which they have been classified. Because Acomys and the brush-furred mice Uranomys and Lophuromys share no derived morphological characters with the Gerbillinae, their murine morphology must have evolved by convergence, including the molar pattern previously considered to support the monophyly of the Murinae.
