| chromosomal localization of the telomeric (ttaggg)n sequence in four species of armadillo (dasypodidae) from argentina: an approach to explaining karyotype evolution in the xenarthra. | the distribution of the vertebrate telomeric sequence (ttaggg)(n) in four species of armadillos (dasypodidae, xenarthra), i.e. chaetophractus villosus (2n = 60), chaetophractus vellerosus (2n = 62), dasypus hybridus (2n = 64) and zaedyus pichiy (2n = 62) was examined by fish with a peptide nucleic acid (pna) probe. besides the expected telomeric hybridization, interstitial (centromeric) locations of the (ttaggg)n sequence were observed in one chromosome pair of chaetophractus vellerosus and zaed ... | 2005 | 16331409 |
| helminth fauna of the screaming hairy armadillo chaetophractus vellerosus from argentina: the consequence of host isolation on parasite diversity. | chaetophractus vellerosus in argentina has a north-west and central distribution. an isolated population is located in the east of the buenos aires province, separated from the population of central argentina by about 500 km. we compared the component community of c. vellerosus between the main population in central argentina and the isolated population, evaluating the impact of the host isolation on parasite diversity. sixteen species of helminths were found, namely ancylostoma caninum, aspidod ... | 2019 | 31193013 |
| morphological diversity of facial vibrissae in chaetophractus vellerosus (mammalia, xenarthra, dasypodidae) and differential mechanoperception. | vibrissae are specialized and complex mechanoreceptor organs present in the skin of most mammals that respond to a diverse mechanical stimuli (e.g. tension, pressure, movement, vibrations) and provide information on distance to the object, its location/orientation, and general characteristics of its surface; also, it may play diverse roles during food acquisition and attacking potential prey. there are scarce papers on the vibrissae of armadillos, only considering their presence/absence and dist ... | 2020 | 32408124 |
| the fetomaternal interface in the placenta of three species of armadillos (eutheria, xenarthra, dasypodidae). | placental characters vary among xenarthra, one of four supraordinal clades of eutheria. armadillos are known for villous, haemochorial placentas similar to humans. only the nine-banded armadillo has been well studied so far. | 2012 | 22559925 |
| genetic approach reveals a polygynous-polyandrous mating system and no social organization in a small and isolated population of the screaming hairy armadillo, chaetophractus vellerosus. | the development of agro-ecosystems in the pastures of the pampean region has substantially modified their structure and functioning. many wild mammal populations in the argentinean pampas face habitat loss and/or fragmentation due to human activities, resulting in harmful genetic effects. the screaming hairy armadillo (chaetophractus vellerosus) is a species considered an indicator of the state of preservation of the environments it inhabits. however, very little information is available about i ... | 2020 | 32193750 |
| axonal projections and conduction properties of olfactory peduncle neurons in the armadillo (chaetophractus vellerosus). | extracellular unit recording was employed to study the axonal properties and efferent projections of antidromically identified neurons in the olfactory peduncle (op) region of a primitive eutherian macrosmatic mammal, the south american armadillo (chaetophractus vellerosus). of 72 cells which satisfied the criteria for antidromic invasion, 55 (76%) and 17 (24%) responded to ipsi- and contralateral olfactory bulb (iob; cob) stimulation, respectively. the absolute refractory period (3.25 +/- 0.3 m ... | 1986 | 3803490 |
| forelimb myology of armadillos (xenarthra: cingulata, chlamyphoridae): anatomical correlates with fossorial ability. | descriptions of myology reflect adaptations of the post-cranium and are essential for understanding the functional morphology of animal limbs. armadillos (cingulata) are the most species-rich group of the basal superorder xenarthra, which is evident by their various lifestyles (subterranean vs. terrestrial) and levels of fossoriality (fossorial vs. semi-fossorial). while there have been several studies on limb bone proportions in numerous armadillos, limb myology has been reported for a limited ... | 2020 | 33111984 |
| prevalence and intensity of fleas parasitizing an isolated population of screaming hairy armadillo in buenos aires province, argentina: host-related factors and temporal dynamics. | fleas (siphonaptera) of an isolated population of chaetophractus vellerosus (mammalia: xenarthra) from magdalena (buenos aires province) were studied, and their presence was associated with host-related factors (age, sex, weight, size, and physical condition) and temporal dynamics (seasonality and year). three species of fleas were identified: polygenis (polygenis) platensis (rhopalopsyllidae), tunga penetrans (tungidae), and pulex irritans (pulicidae). prevalences were significant for year, sea ... | 2017 | 28842764 |
| a computer program for automatic plotting of isopotential contours in cns. | a computer program was developed in a basic (applesoft) version for generating up to five isopotential curves from field potentials recorded in nervous structures. voltages are fed according to a cartesian coordinate system, and an area is delineated each four points in which a certain number of intermediate voltage points are calculated, according to the required resolution. the calculated values are compared to those prefixed for each curve and, if similar, their coordinates are stored in corr ... | 1988 | 3395865 |
| synapsis, recombination, and chromatin remodeling in the xy body of armadillos. | three xenarthrans species chaetophractus villosus, chaetophractus vellerosus, and zaedyus pichiy have been used for the analysis of the structure, behavior, and immunochemical features of the xy body during pachytene. in all these species, the sex chromosomes form an xy body easily identifiable in thin sections by the special and regular packing of the chromatin fibers of the internal region of the xy body ("differential" regions) and those of the peripheral region (synaptic region). spermatocyt ... | 2012 | 22274548 |
| ontogenetic criteria to distinguish vertebral types on the debated xenarthran synsacrum. | the presence of a synsacrum formed by the fusion of vertebrae that come into closed contact with the ilium and ischium is a feature that characterizes the clade xenarthra. nevertheless, the proper identity of each vertebral element that forms it is a matter of discussion. in this article, we provide ontogenetic information about skeletal ossification of the xenarthran synsacrum and define the position of the sacrocaudal limit within it. we analyzed the synsacrum of 25 specimens of nonadult and 1 ... | 2015 | 25503782 |
| the middle ear of the pink fairy armadillo chlamyphorus truncatus (xenarthra, cingulata, chlamyphoridae): comparison with armadillo relatives using computed tomography. | the pink fairy armadillo chlamyphorus truncatus is the smallest extant armadillo and one of the least-known fossorial mammals. the aim of this study was to establish if its middle ear is specially adapted to the subterranean environment, through comparison with more epigeic relatives of the groups euphractinae (chaetophractus villosus, chaetophractus vellerosus, zaedyus pichiy) and dasypodinae (dasypus hybridus). we examined the middle ears using micro-computed tomography and subsequent three-di ... | 2020 | 31997377 |
| phylogeography of screaming hairy armadillo chaetophractus vellerosus: successive disjunctions and extinctions due to cyclical climatic changes in southern south america. | little is known about phylogeography of armadillo species native to southern south america. in this study we describe the phylogeography of the screaming hairy armadillo chaetophractus vellerosus, discuss previous hypothesis about the origin of its disjunct distribution and propose an alternative one, based on novel information on genetic variability. variation of partial sequences of mitochondrial dna control region (cr) from 73 individuals from 23 localities were analyzed to carry out a phylog ... | 2018 | 29324793 |
| a new species of tunga perforating the osteoderms of its armadillo host in argentina and redescription of the male of tunga terasma. | a new species of tunga (siphonaptera: tungidae) collected from armadillos in argentina is described. the new species is characterized by large and pigmented eyes, the presence of two bristles on antennal segment ii, two bristles at the base of the maxilla, and a discoid neosome compressed anteroposteriorly. the gravid female is located in the carapace of the host, perforating the osteoderms. the new species resembles tunga penetrans and tunga terasma in general appearance. however, it differs by ... | 2015 | 25630228 |
| a new species of cyclobulura (nematoda: subuluridae) from zaedyus pichiy and chaetophractus vellerosus (xenarthra: dasypodidae) in argentina. | cyclobulura superinae n. sp. collected from zaedyus pichiy and chaetophractus vellerosus is herein described as the second species in cyclobulura quentin, 1977, and the first subulurid in armadillos. the species is unique in the spur-like structures present at the tip of both spicules, yet they conform to the description of cyclobulura in the structure of the buccal parts. specimens of the new species show longer chordal lobes and more conspicuous radial lobes and are smaller than specimens of c ... | 2010 | 21158635 |
| trichostrongylina parasites of dasypodidae (xenarthra) from argentina; a new species of macielia (molineidae: anoplostrongylinae) in chaetophractus vellerosus and redescription of trichohelix tuberculata. | macielia jorgei n. sp. is described from chaetophractus vellerosus from la rioja, argentina. also trichohelix tuberculata is redescribed in detail. the new species is characterized by parasitizing the small intestine, possessing a bursal membrane and telamon, having complex and sclerotized spicules distally divided into 2 processes, a simple, poorly sclerotized gubernaculum, and synlophe with bilateral symmetry and 12 cuticular ridges. this is the second report of a species of macielia in argent ... | 2013 | 23617773 |
| a new species of moennigia (trichostrongylina: molineidae) a parasite of chaetophractus spp. (xenarthra: dasypodidae) from argentina. | moennigia celinae n. sp. collected from the small intestine of chaetophractus vellerosus and chaetophractus villosus (xenarthra, dasypodidae) from argentina is herein described. this new species belongs to the genus moennigia because it possesses a short uterus with few eggs, atrophied distal branch of the ovejector, vulva near the anus, and a conical tail. the new species has a synlophe with 17 symmetrical ridges and slight ventro-dorsal orientation. the spicule length:body length ratio is simi ... | 2014 | 24552210 |
| ontogenetic variation in the stratum granulosum of the epidermis of chaetophractus vellerosus (xenarthra, dasypodidae) in relation to the development of cornified scales. | the epidermis of mammals is characterized by having a stratum granulosum that produces an orthokeratotic stratum corneum, different from the typical reptilian parakeratotic stratum. nonetheless, some mammals show distinct degrees of parakeratosis in epidermal regions with few or no pilose follicles (e.g., areas subjacent to cornified scales). with respect to the epidermis and the development of cornified scales in the dasypodidae, previous studies have supported the presence of a continuous stra ... | 2014 | 25307183 |
| new sylvatic hosts of trypanosoma cruzi and their reservoir competence in the humid chaco of argentina: a longitudinal study. | a four-year longitudinal study of the structure of sylvatic transmission cycles of trypanosoma cruzi, reservoir host competence and parasite discrete typing units was conducted in a disturbed rural area of the humid chaco in argentina. among 190 mammals examined by xenodiagnosis and polymerase chain reaction amplification, the composite prevalence of infection was substantially higher in dasypus novemcinctus armadillos (57.7%) and didelphis albiventris opossums (38.1%) than in euphractus sexcinc ... | 2013 | 23530075 |
| seasonal changes in ovarian steroid hormone concentrations in the large hairy armadillo (chaetophractus villosus) and the crying armadillo (chaetophractus vellerosus). | knowledge of armadillo reproductive physiology is essential for developing ex situ and in situ assisted reproductive techniques for propagating and/or controlling populations of these animals. the present study included assessment of fecal sex steroids by radioimmunoassay, determining reproductive status via monitoring ovarian activity (in the wild) and therefore reproductive status, in wild females of the large hairy armadillo (chaetophractus villosus) and the crying armadillo (chaetophractus v ... | 2011 | 21247625 |
| a new rictulariid (nematoda: spirurida) in xenarthrans from argentina and new morphological data of pterygodermatites ( paucipectines) chaetophracti. | pterygodermatites is a cosmopolitan genus of nematodes from mammals, and it is frequently encountered in the parasite fauna of armadillos (mammalia, xenarthra, cingulata). in this work, a new species, pterygodermatites ( paucipectines) argentinensis, is described, and new morphometric data, new host records, and the geographical distribution of pterygodermatites ( paucipectines) chaetophracti are provided. we examined 109 hosts belonging to chaetophractus vellerosus, chaetophractus villosus, cab ... | 2017 | 28783421 |
| genetic structuring in a relictual population of screaming hairy armadillo (chaetophractus vellerosus) in argentina revealed by a set of novel microsatellite loci. | the screaming hairy armadillo (chaetophractus vellerosus) is a mammal species containing disjunct and isolated populations. in order to assess the effect of habitat fragmentation and geographic isolation, we developed seven new microsatellite loci isolated from low-coverage genome shotgun sequencing data for this species. among these loci, six microsatellites were found to be polymorphic with 8-26 alleles per locus detected across 69 samples analyzed from a relictual population of the species lo ... | 2016 | 27406582 |