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Armadillos are bitten by several species of flea. Females of the genus Tunga penetrate the epidermis and when in place are fertilised by males, after which the abdomen swells enormously to form a 'neosome'. Within the penetrans group, T. perforans, makes lesions that perforate the osteoderms within the integument to form ~3 mm diameter cavities occupied by a discoid neosome. We examined these lesions in carapace material from animals which had died in the wild to see whether we could recruit evidence as to how they may be generated, either by the insect or by the host. We studied one species without such lesions, the nine‐banded armadillo Dasypus novemcinctus, and two species with, the greater hairy armadillo Chaetophractus villosus and the southern three‐banded armadillo Tolypeutes matacus, both showing the characteristic 'flea bite' holes in the external surfaces of the osteoderms. Samples were studied by three‐dimensional backscattered electron mode scanning electron microscopy and X‐ray microtomography. Both methods showed resorption pit complexes in the external surfaces of the osteoderms characteristic of those made by osteoclasts in active bone resorption. Lesions involved both the syndesmoses (sutures) between adjacent bones and the central regions of the osteoderms. Many lesions showed extensive repair by infilling with new bone. We conclude that the T. perforans neosome creates a local host response which causes bone resorption, creating the space in which it can grow. [ABSTRACT FROM AUTHOR]

Trichinella spp. from a sylvatic cycle has been found in several animal species such as pumas (Puma concolor), armadillos (Chaetophractus villosus), rats (Rattus norvegicus), and wild boars (Sus scrofa) in Argentina. Moreover, Trichinella infection has been detected in a wide range of marine mammals around the world, including polar bears (Ursus maritimus) and walruses (Odobenus rosmarus). Until the present time, Trichinella spp. infection has not been detected in marine mammals of South America. Samples from four South American sea lions (Otaria flavescens) found dead in Rio Negro, Argentina, were analyzed by artificial digestion, and in the case of one animal, Trichinella larvae were identified at the species level by nested multiplex PCR as Trichinella spiralis. This is the first report of a Trichinella species infecting marine mammals from South America. [ABSTRACT FROM AUTHOR]

Different concentrations of a glyphosate formulation, Roundup® Full II (66.2% glyphosate) were tested in culture peripheral blood of armadillo Chaetophractus villosus with cytogenetic biomarkers like mitotic index (MI), chromosomal aberrations (CA), sister chromatid exchange (SCE) and cell proliferation kinetics (CPK) by means of replication index. Adults animals of both sexes were exposed to RU at four concentrations ranging from 0.026 mL RU solution to 0.379 mL RU daily in oral treatment with the same volume (0.2 mL) during 7 days. We analyzed the induced damage at different times considering T0 as control value, one (T1), seven (T7) and 30 days (T30). One day after, only the higher concentration shows MI significant differences (p < 0.05), at T7 the frequency increases and at T30 it decreases reaching T0 values. The analysis of CA frequencies shows that only 0.106 mL RU/day exhibit significant differences vs T0 values. A great variability is expressed in the values of standard deviation (SD) and in the wide confidence intervals of the media. One day after treatments (T1) all four concentrations shows significant differences in SCE vs T0 values. Replication Index (RI) does not show significant differences. The dose-response behavior was not observed in either CA or SCE. The consistency of the findings obtained with the same biomarkers in vitro support the idea of expanding studies in order to characterize the risk doses for these mammals. [ABSTRACT FROM AUTHOR]

In Argentina, Chaetophractus villosus has a wide distribution that overlaps with agricultural areas where soybean is the predominant crop. In such areas the pesticide Roundup Full II® (RU) is widely applied. The genotoxic effect of its active ingredient glyphosate (RU is 66.2% glyphosate) on the peripheral blood lymphocytes of C. villosus was tested over a range of concentrations (280, 420, 560, 1120 μmol/L). Culture medium without glyphosate served as negative control, while medium containing mitomycin C served as positive control. Genetic damage was characterized in terms of the percentage of cells with chromosome aberrations (CA), the mean number of sister chromatid exchanges (SCE) per cell, and the modification of cell proliferation kinetics via the calculation of the replication index. Significant increases (p < 0.0001) were seen in the CA frequency and the mean number of SCEs per cell compared to negative controls at all the RU concentrations tested. Chromatid breaks, the only form of CA observed, under the 560 μmol/L RU conditions and in presence of mitomycin C were four to five times more common than at lower concentrations, while no viable cells were seen in the 1120 μmol/L treatment. The mean number of SCEs per cell was significantly higher under the 280 μmol/L RU conditions than the 420 or 560 μmol/L RU conditions; cells cultivated in the presence of MMC also showed significantly more SCEs. All the RU concentrations tested (except in the 1120 μmol/L RU treatment [no viable cells]) induced a significant reduction in the replication index (p < 0.0001). The present results confirm the genotoxic effects of RU on C. villosus lymphocytes in vitro, strongly suggesting that exposure to RU could induce DNA damage in C. villosus wildlife. [ABSTRACT FROM AUTHOR]

Calyptophractus retusus (Burmeister, 1863), commonly called the greater fairy armadillo, is a small armadillo in a monotypic genus. It is a poorly known, fossorial species with a reduced eye and ear, fixed carapace and greatly enlarged foreclaws adapted for digging. The species is confined to the Chaco region of northern Argentina, western Paraguay, and southern Bolivia where it is apparently locally distributed in areas with soft, sandy soils. The species is considered “Data Deficient” by the International Union for Conservation of Nature and Natural Resources. [ABSTRACT FROM AUTHOR]

Two methods of measurement of bullar dimensions (callipers and scaling from digital images) and subsequent application of four volume formulae (rectangular prism, cylinder, ellipse and elliptical cone) were tested to find the most appropriate non-destructive method for estimating the bullar volume in Chaetophractus villosus. Material for the study consisted in clean adult skull (n=22). Real volume was obtained from latex casts of the tympanic bulla. Each estimation was corrected by a factor based on the differences between the estimated and the real volumes. Highest accuracy (5-7% of underestimation) and precision (coefficient of variation: 13.27%) were obtained from callipers and application of rectangular prism, cylinder and ellipse formulae. The corresponding correction factors were 0.31, 0.39 and 0.58, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Iheringia. Série Zoologia is the property of Fundacao Zoobotanica do Rio Grande do Sul and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In agroecosystems, the use of cultivated plots by mammals depends on habitat structure as well as on the degree of species specialization. In the Pampas of Argentina, during the last 2-3 decades, there has been a continuing expansion of cropland. The aim of this study was to analyze how the identity and characteristics of agricultural plots may have affected the activity of 2 species of armadillos (Chaetophractus villosus and Dasypus hybridus) in a rural landscape. We carried out 4 sampling sessions between December 2011 and June 2013, surveying 175 plots during spring-summer and 194 during fall at 25 different sites in the Pampas of Buenos Aires province, Argentina. In each plot, we surveyed for signs (burrows and holes) along a 600 × 6 m transect in order to assess armadillo activity and measured 4 habitat structural variables. As expected, there were structural differences between types of agricultural plots. Across all plots, a total of 6,654 armadillo signs were found (C. villosus = 5,009, D. hybridus = 1,645). Generalized linear mixed models revealed that during both seasons, the type of plot explained much of the variation in armadillo activity, except during spring-summer for D. hybridus. C. villosus had higher use of plots with a longer history of non-tillage (e.g., soybean), while there was more evidence of D. hybridus activity in plots with less human intervention (e.g., grasslands), especially during fall. Overall, D. hybridus and C. villosus were more sensitive to the particular structural features of plots rather than to the kind of land use practiced (crop field or rangeland). These results have important implications for future management decisions in the Pampas region because during the last decades, farming of soybeans has expanded at the expense of grasslands, and this change appears to have differentially affected these 2 species of armadillos. [ABSTRACT FROM AUTHOR]

We update the distribution of three species of armadillos (Chaetophractus villosus, C. vellerosus and Dasypus hybridus) in the Pampas region within the Province of Buenos Aires, Argentina, with information that comes from fieldworks conducted during 2011-2013. Armadillos were recorded through direct observations and indirect evidence (burrows and foraging holes). We obtained 632 records (10 C. vellerosus, 184 D. hybridus, and 438 C. villosus), which provide information of 27 counties for which there were no documented records of the species, we correct previous data, and we complete information of areas scarcely surveyed in previous years such as the center and western areas of the province. [ABSTRACT FROM AUTHOR]

Hairy armadillos constitute an ecologically homogeneous and morphologically similar group with currently 5 species classified in the subfamily Euphractinae. Among them, the Andean hairy armadillo Chaetophractus nationi (Xenarthra, Cingulata, Dasypodidae) is a small, endangered armadillo that has long been suspected to represent a high-altitude variant of Chaetophractus vellerosus. Here, we report the 1st phylogenetic systematics assessment of hairy armadillos using morphological and molecular analyses of all described species with focus on the status of the Andean hairy armadillo. Multivariate analyses of shape variation based on 3-dimensional landmark coordinates of skulls allowed a clear differentiation of each species with the exception of C. vellerosus and C. nationi, within which only a latitudinal and/or altitudinal gradient in size was apparent. Moreover, analyses of mitochondrial DNA control region (D-loop) revealed a single C. nationi haplotype that appeared to be identical with a C. vellerosus haplotype from Argentina. Identical sequences in C. vellerosus and C. nationi were also observed for 3 of the 5 non-coding nuclear markers investigated. Based on these data, we propose that C. nationi should be considered as a synonym of C. vellerosus. However, this taxonomic change should not preclude the protection of the high-altitude Bolivian populations that are steadily declining because of their overexploitation for traditional purposes. Finally, phylogenetic analyses of euphractine armadillos based on a combination of 6 non-coding nuclear markers and 2 nuclear exons suggest the paraphyly of the genus Chaetophractus, with C. vellerosus being more closely related to Zaedyus pichiy than to C. villosus. [ABSTRACT FROM AUTHOR]

Land use change and agricultural practices are among the main factors affecting biodiversity, and require understanding of how differing species responses shape wildlife communities in rural landscapes. During the last 2–3 decades, the Pampas of central Argentina have experienced an agricultural expansion along with rapid adoption of a non-tillage system. In some areas armadillos are increasingly considered agricultural pests, not only because they can damage and contaminate silo bags and may act as direct consumers of crops, but also their burrowing activities interfere with farming practices. Here, we describe variations in activity of armadillos in the Pampas of Buenos Aires province, central Argentina, and discuss how biogeography, land use, and rainfall may have affected these species in the rural landscape. We carried out four sampling sessions between December 2011 and June 2013 (including two periods of normal rainfall and two periods of high rainfall), surveying 392 plots (196 crop fields and 196 rangelands) at 25 different localities (covering the five different ecological units of the Pampas). In each plot, we surveyed for signs (burrows and holes) along a 600 × 6 m transect, in order to assess armadillo activity. Chaetophractus villosus (large hairy armadillo) showed the highest activity, with 5968 signs at 79% of the plots surveyed; whereas, 1866 signs of Dasypus hybridus (southern long-nosed armadillo) were found in 36% of the plots. Generalized linear mixed models revealed that C. villosus is more active mainly in the Inland Pampas and in cropland plots, whereas, D. hybridus is more active in the Flooding Pampas at plots with active livestock use. Both species showed less burrowing activity during the second year of surveys, in a period of exceptionally high rainfall. Our results suggest that the omnivorous C. villosus may have benefited from agriculturization and non-tillage, particularly in the Inland Pampas where sandy soils favor burrowing, whereas, the more myrmecophagous D. hybridus may be in retraction. [ABSTRACT FROM AUTHOR]

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 stratum granulosum without any variations during ontogeny. This condition, in which the cornified scales develop without a loss of the stratum granulosum, was interpreted as primitive for eutherians. The present contribution expands the knowledge on the epidermis of Chaetophractus vellerosus in distinct ontogenetic stages in order to determine whether the cornified scales show the same developmental pattern as in other eutherians. The presence of a stratum granulosum in C. vellerosus neonates and its reduction in more advanced ontogenetic stages, in direct relationship with cornified scale development, supports the hypothesis that the partial parakeratosis in the xenarthran integument is secondary, as in other eutherians, and can be interpreted as a derived character state. [ABSTRACT FROM AUTHOR]

Patagonia, south of 40° S, is currently inhabited by Chaetophractus villosus and Zaedyus pichiy. In order to reconstruct the Late Pleistocene-Holocene history of these armadillos in southern South America, we compiled and discussed data from zooarcheological sites, notes from naturalists and travellers, museum specimens, and field data. We found that both species experienced significant range expansion southwards. Based on the obtained evidence we concluded that: (a) Southern Patagonia was mainly free of armadillos during the Late Pleistocene-Early Holocene; (b) in the last 10 ky Z. pichiy progressively invaded southern Patagonia from the north, down to the Santa Cruz River (~50° S); at the same time, C. villosus colonized the northern portion of Patagonia north of Chubut River (~44° S); (c) during the last century, Z. pichiy surpassed the Santa Cruz River barrier while C. villosus colonized all Patagonian territories to reach the Magellan Strait and finally was introduced in Tierra del Fuego. Although these armadillos have metabolic, dietary and behavioral adaptations to cold and dry habitats that possibly helped them to extend its range southwards, we propose that the observed distributional changes of the last century were triggered mainly by anthropogenic causes. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Brucellosis is a zoonotic disease transmitted from an animal reservoir to humans. Both, wildlife and domestic animals, contribute to the spreading of these zoonosis. The surveillance of the animal health status is strictly regulated for domestic animals, whereas disease monitoring in wildlife does not exist. The aim of the present study was to provide data on the prevalence of anti-Brucella antibodies in Chaetophractus villosus from a region of La Pampa, Argentina to assess public health risks. The C. villosus is endemic to South America, and in Argentina it represents a food resource for human consumption. A total of 150 sera of armadillos bleeding between 2007 and 2010 were tested using buffered plate antigen test (BPAT), serum agglutination test (SAT), 2-mercaptoethanol (2-ME) and complement fixation test (CFT), for the detection of anti-Brucella antibodies. Antibodies to Brucella sp. were found in 16% (24:150) of the armadillos tested using the BPAT test. All 24 positive samples were confirmed by the SAT, 2-ME and CFT tests. Strain isolation was attempted from liver and spleen samples of two animals with positive serology. Isolates were characterized by conventional biotyping and identification of specific DNA using polymerase chain reaction (PCR). A total of 2 isolates were recovered from spleen and liver. Both of them were identified as Brucella suis biovar 1. This preliminary study provides the first report on the seroprevalence of brucellosis and describes the first isolate of B. suis biovar 1 in C. villosus in Argentina. [Copyright &y& Elsevier]

Karyotype and cytotype variations for the large hairy armadillo (Chaetophractus villosus) were studied throughout the species' Argentine distribution. Peripheral blood lymphocyte cultures of 421 animals were used to obtain mitotic metaphases. Preparations were subjected to conventional staining, G- and C-banding, and FISH involving a telomeric probe. Meiotic analysis was performed on testis material from 10 adults. Spermatocytes were examined for synaptonemal complexes in microspreads. The karyotype (2n = 60 XX/XY; FN = 84 without XY) showed an autosomal complement of 6 metacentric and 7 submetacentric chromosomes; the remainder was acrocentric. The X chromosome was submetacentric and the Y acrocentric. Centromeric C+ marks were observed in all chromosomes except pair 16. Three NOR signals were detected in 6q, 12p, and 26p. Two chromosomal rearrangements were characterized in chromosome pair 1 a pericentric inversion seen in the material from Jacinto Aráuz, General Madariaga and Pellegrini and a deletion in the material from Loma Verde. Interstitial telomeric signals were observed in chromosome pairs 4, 12, 16, and 26. Pachytene spermatocyte analysis confirmed the basic chromosome number and morphologies observed in mitotic karyotypes. The evolution of C. villosus involved chromosomal rearrangements as recorded for other species of its superorder. The present results establish the basis for the cytogenetic characterization of this species. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abstract: The results of zooarchaeological study carried out on the bone remains of armadillos (Mammalia, Dasypodidae) from four Sierras of Córdoba (Argentina) archaeological sites were presented. The radiocarbon dates place chronologically their occupation at the last millennium of the Late Holocene (ca. 970 ± 110 and 290 ± 37 14C BP). Four taxa were identified: Chaetophractus villosus, Chaetophractus vellerosus, Euphractus sp. and Dasypus sp. The diagnostic characters of their bony dermal scutes or osteoderms were described in order to facilitate their taxonomical identification in other modern collection and/or fossil assemblages. C. villosus and C. vellerosus show a current distribution in the study area, while Euphractus sp. and Dasypus sp. are absent in the Sierras of Córdoba. Euphractus was determined on the basis of a fragmented movable osteoderm in C.Pun.39. Their presence may be a response to an increase of precipitation and temperature associated with the “Medieval Warm Period”. The record of Dasypus sp. during the “Little Ice Age” contrasts negatively with its potential as an indicator of warm and humid condition, showing either their adaptive plasticity or the biological fragmentation of the mountain environment under paleoclimatic conditions. Finally, the possibility that the presence of Euphractus and Dasypus is due to anthropogenic transport was considered. [Copyright &y& Elsevier]

Very little is known about the distinct reproductive biology of armadillos. Very few studies have investigated armadillo spermatogenesis, with data available only for Euphractus sexcinctus and Dasypus novemcinctus. In the present study, we analysed male germ cell differentiation in the large hairy armadillo Chaetophractus villosus throughout the year, describing a cycle of the seminiferous epithelium made of eight different stages. Evaluation of the testis/body mass ratio, analysis of the architecture of the seminiferous epithelium and the frequency of defective seminiferous tubules allowed identification of a temporal interruption of spermatogenesis during the period between mid-May to July (mid-end autumn) in correlation with very low testosterone levels. Overall, these results suggest that spermatogenesis is seasonal in C. villosus. Armadillo reproduction differs between species: in one species, females deliver only twins, yet in another embryos undergo developmental arrest. The big hairy armadillo, Chaetophractus villosus, is one of the most widespread throughout South America. Herein, we describe spermatogenesis in this species, demonstrating a block in sperm production from mid-May to July (mid-end autumn), evidence of seasonal reproduction. The findings of the present study may contribute towards the reproductive control of a species that causes agricultural damage and is a reservoir for Chagas disease and Trichinella infection. [ABSTRACT FROM AUTHOR]

Abstract: The integument of extant armadillos (Xenarthra, Cingulata) is a unique organ in which complex glandular systems are associated with pilose follicles, dermal ossifications, and cornified scales. Up to date, papers have focused on neither comparative morphology of the skin (dorsal and ventral) nor chronology of the development of interspecific homolog structures. In order to clarify the way in which events occur during development of the integument structures, maturity of other tissues (e.g. skeletal tissues) should be considered. Therefore, we will be able to identify events that have been pre- or post-displaced during ontogenetic development. The aim of this paper is to describe in a developmental and comparative framework the integumentary system of neonates of Dasypus hybridus and Chaetophractus vellerosus. In order to understand the morphology of the different integumentary structures serial histological sections were prepared. Staining techniques included H–E, Masson Trichrome, PAS, orcein and reticulin. To study ossification of postcranial elements, the specimens were cleared and double-stained with alcian blue and alizarin red. Determinations of ossification centers and their progress were recorded through the early uptake of alizarin. The dorsal dermis of neonates from D. hybridus is clearly differentiated into a superficial and deep layer, as in fetuses of Dasypus novemcinctus. In C. vellerosus, however, these layers could not be identified. This suggests a less connective tissue differentiation in the latter species at this stage. Osteoderms in D. hybridus are well differentiated unlike C. vellerosus where no condensations of osteoprogenitory cells are observed. Conversely, pilose follicles and glandular tissues are less developed in D. hybridus. Regarding postcranial elements, ossification centers are less advanced in C. vellerosus than D. hybridus, this is particularly notorious for the vertebral column, sternal, and pelvic girdle elements. Asynchronies between neonates of both species observed on integumentary and postcranial skeletal tissues could match with specific adaptive strategies related to distribution in different environments, and/or different postnatal care. [Copyright &y& Elsevier]

Background: 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. Methods: Placentas of three species of armadillos were investigated by means of histology, immunohistochemistry including proliferation marker, and transmission and scanning electron microscopy. Results: The gross anatomy differed: Euphractus sexcinctus and Chaetophractus villosus had extended, zonary placentas, whereas Chaetophractus vellerosus had a disk. All taxa had complex villous areas within the maternal blood sinuses of the endometrium. Immunohistochemistry indicated the validity of former interpretations that the endothelium of the sinuses was largely intact. Tips of the villi and the columns entering the maternal tissue possessed trophoblast cell clusters with proliferation activity. Elsewhere, the feto-maternal barrier was syncytial haemochorial with fetal vessels near the surface. Conclusions: Differences among armadillos occurred in regard to the extension of the placenta, whereas the fine structure was similar. Parallels to the human suggest that armadillos are likely to be useful animal models for human placentation. [ABSTRACT FROM AUTHOR]

The article presents a study on the extant armadillos species distribution in Buenos Aires province, Argentina. The study uses data from fieldwork, collections, and literature as well as 401 georeferenced records from seven species. It adds that temporal and spatial aspects are considered within the analysis. Result shows dasypus hybridus and chaetophractus villosus as the most distributed armadillos in the province. Moreover, zaedyus pichiy was observed in the southeast of the province.

Abstract: 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 vellerosus) in the southern hemisphere. Plasma and fresh fecal progesterone concentrations were not significantly correlated in either species. However, in both species, there was a significant positive correlation between plasma progesterone and dry fecal progesterone concentrations (r = 0.82, P < 0.05 and r = 0.60, P < 0.05, respectively). Dry fecal progesterone and estradiol concentrations were measured in one captive C. villosus (average baseline progesterone and estradiol concentrations 28.72 ± 11.75 ng/g dry feces and 3.04 ± 0.80 ng/g dry feces, respectively) and one captive C. vellerosus (average baseline progesterone and estradiol concentrations 14.05 ± 3.03 ng/g dry feces and 3.46 ± 1.20 ng/g dry feces, respectively) to detect hormonal peaks over 1 y; these occurred from late fall to early summer. Feces from wild C. villosus and C. vellerosus were also collected over 1 y to determine progesterone peaks, which occurred in winter and spring in both species (with no peaks during the summer or fall). Accordingly, C. villosus and C. vellerosus had a seasonal reproductive pattern. The significant correlations between dry fecal and plasma progesterone concentrations validated this method for monitoring reproductive status in these species. [Copyright &y& Elsevier]

Abstract: We report a phylogeographic study of Chaetophractus villosus populations in Argentina. Control Region (CR) sequences (484bp) were obtained for 76 C. villosus from 20 locations across the species whole distribution range. Seventeen new haplotypes were identified. The highest genetic variation and the earliest fossils were found in the Pampean Region, thus appearing as the most probable area of origin of the species. A general pattern of Contiguous Range Expansion (CRE) was revealed by Nested Clade Analysis (NCA) supported by mismatch analysis and Fu’s test. The Pampean Region would have been the pre-expansion area, while Patagonia would have been the main dispersal route of contiguous expansion, possibly after the Pleistocenic glaciations. [Copyright &y& Elsevier]

The morphological features of the oviduct in the armadillo Chaetophractus villosus (Desmarest, 1804) were studied. In the simple columnar epithelium, ciliated cells, secretory cells, and cells of the bottom of the folds are described. The most remarkable findings are the increase in number of ciliated cells, when present, from the fimbriae to the uterus, being the isthmus practically lined by ciliated cells, and that secretory cells are more abundant in the apical zone of the ampulla and fimbriae, than in the isthmus. Morphological changes along the year in the different portions are described. [ABSTRACT FROM AUTHOR]

The fibrinolytic mechanism in the armadillo Chaetophractus villosus (Mammalia, Xenarthra, Dasypodidae) quite unknown until now was studied. Results were compared with those corresponding to healthy adult human beings. Whole blood lysis time and diluted blood lysis time were not detectable in armadillos. Euglobulin clot lysis time and plasminogen activity (Plg) were lower than in healthy humans. We established the presence of the fibrinolytic system in Ch. villosus through the measurement of fibrin fibrinogen degradation products. The activity of the plasminogen activator inhibitor was two to four times greater than in healthy humans. The activity of the alpha 2 anti-plasmin (α2AP) was similar and displaced toward lower values. The Plg/α2AP relation was lower. The results obtained suggest that Ch. villosus has a hypercoagulable and hypofibrinolytic profile. Our findings are not only the first contribution to elucidate the physiology of the fibrinolytic system in Xenarthra but also contribute to develop an animal model for studies in haemostasis and thrombosis. [ABSTRACT FROM AUTHOR]

Analysis of the stomach contents of 28 little hairy armadillos (Chaetophractus vellerosus), collected during a 14-month period at Pipinas, Argentina, showed that about 63.6% of the weight of prey items was composed of animal remains, 18% was plant material, and the remaining 18.4% was undetermined organic remains. Insects were the most frequent diet item, followed by plant material, amphibians, reptiles, and lastly birds and mammals in similar proportion. During autumn, plant material was the most abundant item, followed by vertebrates and invertebrates. During winter invertebrates prevailed, followed by a lower percentage of vertebrates and scarce plant remains. Invertebrates also were predominant during spring, whereas plant material and vertebrates composed very low percentages. [ABSTRACT FROM AUTHOR]

The morphology and relative size of the tympanic bulla of three species of dasypodids from Argentina, Chaetophractus villosus, C. vellerosus and Zaedyus pichiy, were studied. The bulla was observed to be morphologically similar and evidently hypertrophied in the three species. The degree of hypertrophy was higher in C. vellerosus and C. villosus than in Z. pichiy. By means of ANCOVA it was clear that, although C. villosus has a bigger skull than C. vellerosus, the relative size of their tympanic cavity was similar in both species. On the other hand, the skull of C. vellerosus and Z. pichiy are of similar size but the bulla was relatively shorter in the later. [ABSTRACT FROM AUTHOR]

We evaluated the effects of land use on the distribution of 3 sympatric species of armadillos, Chaetophractus villosus, C. vellerosus, and Dasypus hybridus, on 34 farms in the eastern Pampas. We characterized 4 soil and vegetation variables around each burrow located during surveys of these farms, and related burrow abundance to 10 variables used to characterize each farm. C. vellerosus was the most specialized, using primarily native woodlands and areas with calcareous soil. D. hybridus was associated with natural grasslands and avoided cultivated pastures, and was negatively related to the number of dogs that lived on the farms. C. villosus, the most abundant species, was found in all 4 types of habitats, but its distribution depended on the intensity of hunting on each farm. [ABSTRACT FROM AUTHOR]

Blood coagulation is an important process regulated by a large number of proteins, which transform fibrinogen into fibrin. This mechanism was identified in several species other than humans. In this work we study the coagulation factors and principal natural anticoagulants in armadillos ( Chaetophractus villosus). Coagulation factors FVII, FXII, FIX, FXI, FX, FVIII, FV, antithrombin (AT), protein C (PC), and protein S (PS) were identified. The activities of all factors were homogeneous for both sexes. Correlation studies showed associations between FVII and FX, FVII and FIX, FVII and FXI, FIX and FXI, and FIX and FX. Sex-related differences were observed for PS but not for AT or PC. There was positive correlation between PS and FV in females. These data constitute the first contribution to the knowledge of the proteins participating in the coagulation in this species and they demonstrate that the hemostatic process is similar in the armadillos and man. [ABSTRACT FROM AUTHOR]

Haemostatic mechanisms in humans are formed by two activation pathways, named tissular factor pathway and contact system pathway, and a common pathway, that promotes the formation of the fibrin clot. These mechanisms have also been identified in other mammals. In this work we evaluate their presence in the armadillo Chaetophractus villosus, a mammal of the neotropical Xenarthra Order. Twenty animals (ten males and ten females), previously adapted to captivity, were used. Fibrinogen (Fbg) was measured at the beginning and at the end of the experimental period; prothrombin time (PT), activated partial thromboplastin time (APTT) and thrombin time (TT) were measured at the same time during the experience. Neither Fbg nor the other parameters evaluated showed sex-related differences, but Fbg diminished during the experimental period. TT related to PT and APTT showed longer times and larger dispersion of the individual values. Compared to the human beings, PT and TT were longer and APTT was shorter. Considering those results, we conclude that C. villosus has the same basic coagulation system as human beings. However, in this species the contact system pathway seems to play a greater role in the activation of the coagulation system than it does in man, and the common pathway appears to limit the velocity of the system. [ABSTRACT FROM AUTHOR]

The anatomical, histological, histochemical and ultrastructural characteristics of the Harderian gland of the armadillo Chaetophractus villosus were described. The gland is the largest structure in the bony orbit. It is situated in the anteroventral region of the orbit. Obvious structural differences are not observed between males and females. The gland is compound-branched tubulo-alveolar, being characterized by a single layer of columnar cells surrounded by myoepithelial cells. It possesses a single excretory duct opened into the inner canthus. All glandular cells show yellow-green autofluorescence and additionally some glandular lumen may contain dense autofluorescent solid accretions. There are two peculiar and outstanding cytoplasmic features. One is represented by the smooth endoplasmic reticulum (SER), forming a closely woven meshwork. The other one is represented by “membranous bodies” apparently derived from the SER, RER and cytoskeleton with a “Star of David” configuration situated in the supranuclear region. Three types of vesicles are detected in the cytoplasm. Histochemical staining methods reveal lipids, proteins, neutral and acidic containing glycoconjugates in secretory vesicles. The mechanism of secretion appears either merocrine or apocrine. The epithelium of the intra- and inter-lobular excretory ducts suggests secretory activity. Tubulo-acinar glands similar to those seen in the lacrimal gland and nictitans glands are found related to the intralobular and main excretory ducts. The capillary network is characterized by fenestrated endothelium. The stroma possesses unmyelinated axons and plasma cells. The normal secretion of the secretory endpieces, particularly lipids, proteins and glycoconjugates, is complemented by mucous and serous secretions released by ductal cells and glands associated to the ducts. [ABSTRACT FROM AUTHOR]