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David J Hafner - One of the best experts on this subject based on the ideXlab platform.
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Host-parasite associations of the Cratogeomys fumosus species group and their chewing lice, Geomydoecus
Therya, 2019Co-Authors: Alex Popinga, David J Hafner, James W. Demastes, Theresa A. Spradling, Mark S. HafnerAbstract:Chewing lice (Phthiraptera: Trichodectidae) and the pocket gophers (Rodentia: Geomyidae) that they inhabit have shared an intimate historical association that has made them a textbook study for cophylogeny. Herein, we examine the chewing lice found on pocket gophers of the Cratogeomys fumosus species group using DNA sequence data from the mitochondrial cytochrome c oxidase subunit I gene to determine relationships among lice for comparison to published host phylogeny. Although matrix approaches indicate a correlation between host and parasite genetic distances, cophylogenetic reconstruction methods fail to detect a pattern of widespread cophylogeny. In conclusion, this study provides an exception to the rule of host-parasite cophylogeny that could be the result of the young age of the relationships considered herein and the complex history of the Trans-Mexican Volcanic Belt.
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evolution and phylogeography of the thomomys umbrinus species complex rodentia Geomyidae
Journal of Mammalogy, 2014Co-Authors: Verity L Mathis, Mark S. Hafner, David J HafnerAbstract:The southern pocket gopher, Thomomys umbrinus, currently contains 17 subspecies distributed from southeastern Arizona and southwestern New Mexico southward into the Trans-Mexico Volcanic Belt (TMVB) of central Mexico. Here we reevaluate relationships within this species, which, based on previous studies, is composed of 3 genetically divergent clades. Multilocus phylogenetic analyses uphold these clades (Northern Desert, Central Plateau, and TMVB) as well as the monophyly of T. umbrinus with respect to the 3 other species in the T. umbrinus complex (T. atrovarius, T. nayarensis, and T. sheldoni). Reanalysis of published allozyme data shows a pattern of isolation by distance consistent with the hypothesis of gene flow among the 3 T. umbrinus clades. Species tree analyses of these clades reveal 4 divergent lineages (2 within the TMVB clade), which we recognize herein at the subspecies level. Cranial morphometrics show a moderate level of morphological separation among these clades in multivariate space. The present center of diversity of the T. umbrinus species group is in the southern Sierra Madre Occidental, which also appears to be the center of origin of the T. umbrinus complex. A synonymy of T. umbrinus is provided.
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rediscovery of the pocket gopher orthogeomys lanius rodentia Geomyidae in veracruz mexico
Journal of Mammalogy, 2014Co-Authors: Mark S. Hafner, David J Hafner, James W. Demastes, Theresa A. Spradling, Erick E Gonzales, Fernando A CervantesAbstract:Abstract The pocket gopher Orthogeomys lanius (Elliot, 1905), unknown to science since the first 2 specimens were captured in 1904, is rediscovered in the mountains south and east of Pico de Orizaba in Veracruz, Mexico. Mitochondrial DNA extracted from the skin of the 109-year-old paratype specimen is nearly identical (0.3% cytochrome-b divergence) to that extracted from 2 newly captured specimens. Phylogenetic analyses of the complete cytochrome-b gene and 2 nuclear genes show O. lanius to be sister to the geographically widespread species O. hispidus. O. lanius has a diploid number of 44 and a fundamental number of 84, and the species is easily distinguished from O. hispidus by its larger size and dense, woolly pelage. Our observations suggest that O. lanius is reasonably abundant in a roughly 1,000-km2 region of central Veracruz, where it persists in forested refugia often too steep and rugged for cultivation by humans.
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conservation status of rodents of the families Geomyidae and heteromyidae of mexico
Revista Mexicana De Biodiversidad, 2014Co-Authors: Jesus A Fernandez, Mark S. Hafner, David J Hafner, Fernando A CervantesAbstract:Mexico is considered a mammal diversity hotspot, and most conservation efforts involving mammals focuson large and charismatic species. Herein, we provide an assessment of the conservation status of species that are oftenoverlooked in conservation programs, Mexican rodents of the families Geomyidae (pocket gophers) and Heteromyidae(pocket mice and kangaroo rats). Based on distributional maps and recent systematic studies, a taxonomic andbiogeographical distributional checklist was made. The conservation lists of the International Union for Conservationof Nature and the Mexican Secretaria de Medio Ambiente y Recursos Naturales were used to identify 8 geomyidspecies, and 8 species and 27 subspecies of heteromyids as endangered. Major threats to their conservation are changein land use, destruction of habitat and a lack of knowledge about their current distribution and population trends.
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conservation status of rodents of the families Geomyidae and heteromyidae of mexico estado de conservacion de los roedores de las familias Geomyidae y heteromyidae de mexico
2014Co-Authors: Jesus A Fernandez, Mark S. Hafner, David J Hafner, Fernando A CervantesAbstract:Mexico is considered a mammal diversity hotspot, and most conservation efforts involving mammals focus on large and charismatic species. Herein, we provide an assessment of the conservation status of species that are often overlooked in conservation programs, Mexican rodents of the families Geomyidae (pocket gophers) and Heteromyidae (pocket mice and kangaroo rats). Based on distributional maps and recent systematic studies, a taxonomic and biogeographical distributional checklist was made. The conservation lists of the International Union for Conservation of Nature and the Mexican Secretaria de Medio Ambiente y Recursos Naturales were used to identify 8 geomyid species, and 8 species and 27 subspecies of heteromyids as endangered. Major threats to their conservation are change in land use, destruction of habitat and a lack of knowledge about their current distribution and population trends.
Mark S. Hafner - One of the best experts on this subject based on the ideXlab platform.
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Host-parasite associations of the Cratogeomys fumosus species group and their chewing lice, Geomydoecus
Therya, 2019Co-Authors: Alex Popinga, David J Hafner, James W. Demastes, Theresa A. Spradling, Mark S. HafnerAbstract:Chewing lice (Phthiraptera: Trichodectidae) and the pocket gophers (Rodentia: Geomyidae) that they inhabit have shared an intimate historical association that has made them a textbook study for cophylogeny. Herein, we examine the chewing lice found on pocket gophers of the Cratogeomys fumosus species group using DNA sequence data from the mitochondrial cytochrome c oxidase subunit I gene to determine relationships among lice for comparison to published host phylogeny. Although matrix approaches indicate a correlation between host and parasite genetic distances, cophylogenetic reconstruction methods fail to detect a pattern of widespread cophylogeny. In conclusion, this study provides an exception to the rule of host-parasite cophylogeny that could be the result of the young age of the relationships considered herein and the complex history of the Trans-Mexican Volcanic Belt.
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evolution and phylogeography of the thomomys umbrinus species complex rodentia Geomyidae
Journal of Mammalogy, 2014Co-Authors: Verity L Mathis, Mark S. Hafner, David J HafnerAbstract:The southern pocket gopher, Thomomys umbrinus, currently contains 17 subspecies distributed from southeastern Arizona and southwestern New Mexico southward into the Trans-Mexico Volcanic Belt (TMVB) of central Mexico. Here we reevaluate relationships within this species, which, based on previous studies, is composed of 3 genetically divergent clades. Multilocus phylogenetic analyses uphold these clades (Northern Desert, Central Plateau, and TMVB) as well as the monophyly of T. umbrinus with respect to the 3 other species in the T. umbrinus complex (T. atrovarius, T. nayarensis, and T. sheldoni). Reanalysis of published allozyme data shows a pattern of isolation by distance consistent with the hypothesis of gene flow among the 3 T. umbrinus clades. Species tree analyses of these clades reveal 4 divergent lineages (2 within the TMVB clade), which we recognize herein at the subspecies level. Cranial morphometrics show a moderate level of morphological separation among these clades in multivariate space. The present center of diversity of the T. umbrinus species group is in the southern Sierra Madre Occidental, which also appears to be the center of origin of the T. umbrinus complex. A synonymy of T. umbrinus is provided.
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rediscovery of the pocket gopher orthogeomys lanius rodentia Geomyidae in veracruz mexico
Journal of Mammalogy, 2014Co-Authors: Mark S. Hafner, David J Hafner, James W. Demastes, Theresa A. Spradling, Erick E Gonzales, Fernando A CervantesAbstract:Abstract The pocket gopher Orthogeomys lanius (Elliot, 1905), unknown to science since the first 2 specimens were captured in 1904, is rediscovered in the mountains south and east of Pico de Orizaba in Veracruz, Mexico. Mitochondrial DNA extracted from the skin of the 109-year-old paratype specimen is nearly identical (0.3% cytochrome-b divergence) to that extracted from 2 newly captured specimens. Phylogenetic analyses of the complete cytochrome-b gene and 2 nuclear genes show O. lanius to be sister to the geographically widespread species O. hispidus. O. lanius has a diploid number of 44 and a fundamental number of 84, and the species is easily distinguished from O. hispidus by its larger size and dense, woolly pelage. Our observations suggest that O. lanius is reasonably abundant in a roughly 1,000-km2 region of central Veracruz, where it persists in forested refugia often too steep and rugged for cultivation by humans.
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conservation status of rodents of the families Geomyidae and heteromyidae of mexico
Revista Mexicana De Biodiversidad, 2014Co-Authors: Jesus A Fernandez, Mark S. Hafner, David J Hafner, Fernando A CervantesAbstract:Mexico is considered a mammal diversity hotspot, and most conservation efforts involving mammals focuson large and charismatic species. Herein, we provide an assessment of the conservation status of species that are oftenoverlooked in conservation programs, Mexican rodents of the families Geomyidae (pocket gophers) and Heteromyidae(pocket mice and kangaroo rats). Based on distributional maps and recent systematic studies, a taxonomic andbiogeographical distributional checklist was made. The conservation lists of the International Union for Conservationof Nature and the Mexican Secretaria de Medio Ambiente y Recursos Naturales were used to identify 8 geomyidspecies, and 8 species and 27 subspecies of heteromyids as endangered. Major threats to their conservation are changein land use, destruction of habitat and a lack of knowledge about their current distribution and population trends.
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conservation status of rodents of the families Geomyidae and heteromyidae of mexico estado de conservacion de los roedores de las familias Geomyidae y heteromyidae de mexico
2014Co-Authors: Jesus A Fernandez, Mark S. Hafner, David J Hafner, Fernando A CervantesAbstract:Mexico is considered a mammal diversity hotspot, and most conservation efforts involving mammals focus on large and charismatic species. Herein, we provide an assessment of the conservation status of species that are often overlooked in conservation programs, Mexican rodents of the families Geomyidae (pocket gophers) and Heteromyidae (pocket mice and kangaroo rats). Based on distributional maps and recent systematic studies, a taxonomic and biogeographical distributional checklist was made. The conservation lists of the International Union for Conservation of Nature and the Mexican Secretaria de Medio Ambiente y Recursos Naturales were used to identify 8 geomyid species, and 8 species and 27 subspecies of heteromyids as endangered. Major threats to their conservation are change in land use, destruction of habitat and a lack of knowledge about their current distribution and population trends.
Jonathan J M Calede - One of the best experts on this subject based on the ideXlab platform.
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locomotory adaptations in entoptychine gophers rodentia Geomyidae and the mosaic evolution of fossoriality
Journal of Morphology, 2019Co-Authors: Jonathan J M Calede, Joshua X Samuels, Meng ChenAbstract:: Pocket gophers (family Geomyidae) are the dominant burrowing rodents in North America today. Their fossil record is also incredibly rich; in particular, entoptychine gophers, a diverse extinct subfamily of the Geomyidae, are known from countless teeth and jaws from Oligocene and Miocene-aged deposits of the western United States and Mexico. Their postcranial remains, however, are much rarer and little studied. Yet, they offer the opportunity to investigate the locomotion of fossil gophers, shed light on the evolution of fossoriality, and enable ecomorphological comparisons with contemporaneous rodents. We present herein a quantitative study of the cranial and postcranial remains of eight different species of entoptychine gophers as well as many contemporary rodent species. We find a range of burrowing capabilities within Entoptychinae, including semifossorial scratch-digging animals and fossorial taxa with cranial adaptations to burrowing. Our results suggest the repeated evolution of chisel-tooth digging across genera. Comparisons between entoptychine gophers and contemporaneous rodent taxa show little ecomorphological overlap and suggest that the succession of burrowing rodent taxa on the landscape may have had more to do with habitat partitioning than competition.
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geometric morphometric analyses of worn cheek teeth help identify extant and extinct gophers rodentia Geomyidae
Palaeontology, 2017Co-Authors: Jonathan J M Calede, Jennifer W GlusmanAbstract:Studies of the biostratigraphy and palaeoecology of fossil vertebrate assemblages require large samples of accurately identified specimens. Such analyses can be hampered by the inability to assign isolated and worn remains to specific taxa. Entoptychine gophers are a diverse group of burrowing rodents found in Oligo-Miocene deposits of the western United States. In both entoptychines and their extant relatives the geomyines, diagnostic characters of the occlusal surface of the teeth are modified with wear, making difficult the identification of many isolated fossil teeth. We use geometric morphometrics to test the hypothesis that tooth shape informs taxonomic affinities and expected levels of morphological variation across gopher taxa. We also incorporate data from microcomputer tomography to investigate changes in occlusal surface shape through wear within individuals. Our analyses demonstrate the usefulness of our approach in identifying extant geomyines to the genus, subgenus and species levels, and fossil entoptychines to the genus and, in some cases, the species level. Our results cast doubt on the validity of some species within Entoptychus and suggest future revisions to entoptychine taxonomy. The amounts of morphological divergence observed among fossil and extant genera are similar. Fossil species do not differ greatly from extant ones in that regard either. Further work evaluating the morphological variation within and across entoptychine species, including unworn teeth and osteological material, will allow revised analyses of the biostratigraphy and palaeoecology of important Oligo-Miocene mammalian assemblages of the western United States and help to infer the phylogenetic relationships and evolution of gophers.
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Turnover in burrowing rodents: The roles of competition and habitat change
Palaeogeography Palaeoclimatology Palaeoecology, 2011Co-Authors: Jonathan J M Calede, Samantha S. B. Hopkins, Edward Byrd DavisAbstract:Abstract Changes in the burrowing herbivore fauna during the Cenozoic have led to the suggestion that competitive replacement was a driving force in the ecology and evolution of the burrowing herbivore guild. Alternatively, it has been proposed that differences in habitat preferences were associated with the expansion and contraction of the ranges of burrowing herbivores. We examine hypotheses of drivers of mammalian evolution in this guild by looking for evidence of apparent competitive replacements at a regional scale in the middle to late Miocene fossil record of the northern Great Basin. Mylagaulids are most common from 17.5 to 9 Ma, in the Hemingfordian through Clarendonian North American Land Mammal Ages and decline to extinction in the Hemphillian (9 to 5 Ma), at which time the family Geomyidae became more common in this region. In addition to observing this turnover within the guild, we find that geomyids and mylagaulids may occupy different habitats as indicated by evidence from mammalian assemblages and paleopedology. This suggests that mylagaulids and geomyids, rather than competing, may be tracking the extent of their preferred environment. We find no evidence for direct biotic interaction between the members of the guild and suggest instead that the changing abundance of mylagaulids and geomyids in Oregon's Miocene was shaped by habitat partitioning.
Eric P Hoberg - One of the best experts on this subject based on the ideXlab platform.
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Broadening diversity in the Arostrilepis horrida complex: Arostrilepis kontrimavichusi n. sp. (Cyclophyllidea: Hymenolepididae) in the western red-backed vole Myodes californicus (Merriam) (Cricetidae: Arvicolinae) from temperat
Systematic Parasitology, 2016Co-Authors: Arseny A. Makarikov, Eric P HobergAbstract:Specimens originally identified provisionally as Hymenolepis horrida (Linstow, 1901) [later Arostrilepis horrida (Linstow, 1901)] in Myodes californicus (Merriam) from near the Pacific coastal zone of southern Oregon are revised. Specimens in western red-backed voles represent an undescribed species of Arostrilepis Mas Coma & Tenora, 1997, contributing to recognition and resolution of a broadening complex encompassing cryptic diversity for these hymenolepidid tapeworms distributed across the Holarctic region. Consistent with recent studies defining diversity in the genus, the form, dimensions, and spination (pattern, shape and size) of the cirrus are diagnostic. Among 12 nominal congeners, specimens of A. kontrimavichusi n. sp. are further distinguished by the relative position and length of the cirrus-sac, arrangement of the testes and relative size of the external seminal vesicle and seminal receptacle. Specimens from Oregon voles represent the fifth endemic hymenolepidid in this genus from the Nearctic. Host range for the North American assemblage of species includes Cricetidae (Arvicolinae and Neotominae), Heteromyidae, Geomyidae, and rarely Sciuridae.
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Broadening diversity in the Arostrilepis horrida complex: Arostrilepis kontrimavichusi n. sp. (Cyclophyllidea: Hymenolepididae) in the western red-backed vole Myodes californicus (Merriam) (Cricetidae: Arvicolinae) from temperate latitudes of the Pac
Systematic Parasitology, 2016Co-Authors: Arseny A. Makarikov, Eric P HobergAbstract:Specimens originally identified provisionally as Hymenolepis horrida (Linstow, 1901) [later Arostrilepis horrida (Linstow, 1901)] in Myodes californicus (Merriam) from near the Pacific coastal zone of southern Oregon are revised. Specimens in western red-backed voles represent an undescribed species of Arostrilepis Mas Coma & Tenora, 1997, contributing to recognition and resolution of a broadening complex encompassing cryptic diversity for these hymenolepidid tapeworms distributed across the Holarctic region. Consistent with recent studies defining diversity in the genus, the form, dimensions, and spination (pattern, shape and size) of the cirrus are diagnostic. Among 12 nominal congeners, specimens of A. kontrimavichusi n. sp. are further distinguished by the relative position and length of the cirrus-sac, arrangement of the testes and relative size of the external seminal vesicle and seminal receptacle. Specimens from Oregon voles represent the fifth endemic hymenolepidid in this genus from the Nearctic. Host range for the North American assemblage of species includes Cricetidae (Arvicolinae and Neotominae), Heteromyidae, Geomyidae, and rarely Sciuridae.
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new species of arostrilepis eucestoda hymenolepididae in members of cricetidae and Geomyidae rodentia from the western nearctic
Journal of Parasitology, 2012Co-Authors: Arseny A. Makarikov, Scott Lyell Gardner, Eric P HobergAbstract:Specimens originally identified as Arostrilepis horrida from the Nearctic are revised, contributing to the recognition of a complex of cryptic species distributed across the Holarctic region. Previously unrecognized species are described based on specimens in cricetid (Neotominae) and geomyid rodents. Arostrilepis mariettavogeae n. sp. in Peromyscus californicus from Monterey County, California and Arostrilepis schilleri n. sp. in Thomomys bulbivorus from Corvallis, Oregon are characterized. Consistent with recent studies defining diversity in the genus, form, size, and spination (pattern, shape, and size) of the cirrus are diagnostic; species are further distinguished by the relative position and length of the cirrus sac and arrangement of the testes. Species of Arostrilepis have not previously been described in rodents outside of the Arvicolinae or from localities in the Nearctic. These studies emphasize the need for routine deposition of archival specimens and information, from survey, ecological, and biogeographic studies, in museum collections to serve as self-correcting records for biodiversity at local, regional, and continental scales.
Barbara R. Stein - One of the best experts on this subject based on the ideXlab platform.
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Comparative Hind Limb Morphology in Geomyine and Thomomyine Pocket Gophers
Journal of Mammalogy, 1993Co-Authors: Barbara R. SteinAbstract:Dissections of hind limb muscles in pocket gophers ( Geomys, Thomomys, Cratogeomys, Orthogeomys ) revealed 14 myological differences that supported both the monophyly of the Geomyidae with respect to the Heteromyidae and the separation of this family into two tribes. However, observed differences did not reflect reported functional similarities of the hind limbs in these taxa and they contrasted in nature with the types of myological variation observed in the forelimbs of these mammals. These results demonstrate the usefulness of myological characters in phylogenetic analyses and highlight the need for quantitative, functional studies that would clarify the action of hind limb muscles in these rodents.
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morphological constraints in the digging apparatus of pocket gophers mammalia Geomyidae
Biological Journal of The Linnean Society, 1992Co-Authors: Enrique P Lessa, Barbara R. SteinAbstract:The digging apparatus of pocket gophers offers a unique opportunity to examine morphological constraints within a historical context because relationships among extant taxa are well resolved and the features enhancing digging performance are relatively well understood. Structural and functional considerations suggest that the muscles associated with tooth- and claw-digging in pocket gophers are subjected to contrasting levels of morphological constraints. To assess this hypothesis, we analysed the bones and muscles of the jaws and forelimbs in four genera comprising five species of pocket gophers. Morphometric analyses were performed on 12 osteological measurements selected to reflect overall skull size, variation in rostral shape and procumbency, differences in overall length of the forelimbs and processes relating to the function of lever systems used in claw-digging. In addition, dissections were made of the jaw, hyoid, neck and all of the forelimb muscles excluding the intrinsic muscles of the manus. Results of our morphometric analyses corroborate the recent suggestion that pocket gophers encompass a wide range of morphological variation extending from claw-diggers to tooth-diggers. Myologically, however, we found structural variation only in the forelimb muscles, some of which may be advantageous for digging. No changes in jaw, neck and hyoid muscles, other than differences in muscle mass or those concordant with differences in rostral shape, were noted. These results support our hypothesis that constrasting levels of morphological constraint exist between the jaw and forelimb muscles of pocket gophers. We present a discussion of the structural and functional constraints on jaws and forelimbs in gophers as well as an analysis of historical constraints acting on this group, and perhaps on mammals in general.