High Trypanosoma cruzi prevalence in armadillo (Zaedyus pichiy; Xenarthra: Chlamyphoridae) populations from Mendoza, Argentina.

Armadillos are considered important reservoir hosts for Trypanosoma cruzi, the causative agent of Chagas disease. The first report of T. cruzi infection in pichis (Zaedyus pichiy), a small armadillo species endemic to central Argentina and Chile, dates back to 1935. However, more recent reports on T. cruzi in this species are scarce. The objective of this study was to assess T. cruzi infection and parasite load in Z. pichiy from Mendoza Province, an area endemic to human Chagas disease. Blood samples were obtained in 2014-2016 from pichis from Lavalle (low Monte), Malargüe (Patagonian steppe), and San Carlos (ecotone) departments, Mendoza Province, Argentina. The detection and quantification of T. cruzi was performed through qPCR amplification using satellite primers. Of the 265 analyzed samples, 201 (76%) were positive for T. cruzi. Parasite loads varied between < 0.1-55.8 parasite-equivalents/mL (par-eq/mL), with a median of 1.1 par-eq/mL in quantifiable samples. The prevalence was similar in Malargüe and Lavalle (85-94%), but significantly lower in pichis from San Carlos (50%). Animals from Lavalle captured after hibernation had significantly higher parasite loads (median 2.0 par-eq/mL). In Malargüe, T. cruzi infection and parasite loads were significantly lower before than after hibernation in 2016. The high prevalence and low median parasite load suggest a chronic and persistent infection of T. cruzi in pichis. Regional differences and a marked increase in precipitation during 2015-2016 could have influenced annual and seasonal infection rates of this vector-borne disease.

Trypanosoma cruzi Survey in Poached Pichis (Zaedyus pichiy; Mammalia, Cingulata) from Mendoza, Argentina.

The transmission cycles of Trypanosoma cruzi, the causative agent of Chagas disease, include a wide variety of mammals and hematophagous triatomine insects. Infection with this blood parasite has been confirmed in many armadillo species; however, information on infection in Zaedyus pichiy, a small armadillo that inhabits areas endemic to Chagas disease, is scarce. Our objective was to determine the infection frequency and parasite load of T. cruzi in 49 wild Z. pichiy confiscated dead from poachers in Mendoza, Argentina, 2010-2017. We detected T. cruzi DNA in 32 of 49 armadillos (65%) using real-time PCR, confirming infection with T. cruzi in a high proportion of confiscated pichis. No differences were found related to sex, age, or ecoregion origin of the assessed pichis. Parasite loads ranged between <0.1 and 8.88 parasite equivalents/microgram cardiac tissue. Additional studies on the infection status of Z. pichiy are needed to determine their role in the maintenance of the sylvatic transmission cycle and the potential zoonotic risk from hunted pichis.

Non-Invasive Assessment of the Seasonal Stress Response to Veterinary Procedures and Transportation of Zoo-Housed Lesser Anteater (Tamandua tetradactyla).

Management procedures affect behavioural and physiological stress responses of wild mammals under human care. According to the Reactive Scope Model, normal values are presumed to exist within predictive and reactive ranges. First, stress parameters of zoo-housed adult Tamandua tetradactyla were evaluated in winter and summer (29 days each), determining the level of behaviour and/or physiological parameters needed to respond to predictable environmental changes. Secondly, the effects of veterinary procedures and transportation were studied in both seasons. Non-invasive methods were applied, assessing behaviour through videos and adrenocortical activity by faecal glucocorticoid metabolites (FGMs). Lesser anteaters exhibited seasonality (summer > winter) in some behavioural parameters, such as nocturnal activities, as well as in the activity cycle (e.g., acrophase) and FGMs. A veterinary check elicited an increase in total activity (TA), natural behaviours and repetitive locomotion and affected the activity cycle, particularly in summer. Transport produced changes in TA, nocturnal and natural activity and some variables of the activity cycle, mostly during summer. Although the effects of routine management procedures were different from each other and presumably stressful, they elicited changes only at the behavioural level, which was greater during summer. The differences observed according to non-invasive methodologies highlight the importance of a multidisciplinary approach in this context and suggest that it is unlikely that individual welfare was affected.

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 number of species. Many of these descriptions need updating, and detailed quantitative muscle data are available only for nine-banded armadillos. The main objective of this study is to assess the forelimb myology of the pichi (Zaedyus pichiy), screaming hairy (Chaetophractus vellerosus), large hairy (Chaetophractus villosus), and pink fairy (Chlamyphorus truncatus) armadillos with comparisons to previous observations to specify muscle traits that indicate scratch-digging specializations in cingulates. Several myological features are variable among the species studied, including the origin of m. trapezius pars cervicalis, presence of a distinct m. rhomboideus profundus and m. omotransversarius, and number of heads present for m. triceps brachii and m. flexor digitorum profundus, all of which can be associated with variability in their respective habitats and functional habits. These traits are consistently observed in the members of the Euphractinae, whereas they are slightly divergent (i.e., reduced complexity) in the pink fairy armadillo despite a similar distribution of muscle mass in the limb retractors, elbow extensors, and carpal/digital flexors across species. The ecomorphology observed here among cingulates also confirms their recent reorganization into separate families and subfamilies.

High rates of Trypanosoma cruzi infection in goats from Mendoza province, Argentina: Parasite loads in blood and seasonal variation.

Mendoza province, in central west Argentina, is considered among the high-risk provinces for vector transmission of Trypanosoma cruzi, the causative agent of Chagas disease. Extensive goat farming is common in large parts of rural Mendoza, and goats may act as a reservoir for this parasite. The objective of this study was to determine infection rates, parasite loads, and seasonal variation of these parameters in T. cruzi infection in goats from rural areas of three departments of Mendoza. A total of 349 peripheral blood samples with EDTA / guanidine were analyzed from goats on 11 farms (three in Lavalle, three in San Carlos, and five in Malargüe department) in spring of 2014, 2015, and 2016; and in fall of 2015 and 2016 (only Malargüe). DNA was extracted using a Phenol: Chloroform: Isoamyl protocol. The detection and quantification of T. cruzi was performed through qPCR amplification using satellite oligonucleotides. Of the 349 blood samples, 267 (77%) were positive, with parasite loads ranging between <0.10 and 10.90 par-eq/mL (median 0.10). In spring, frequencies of infection in the three departments ranged between 86% and 95%, but differences were not significant. Median parasite loads were higher in Lavalle than in the other departments, while those in goats from San Carlos were consistently low. The frequency of infection and parasite loads in Malargüe were significantly higher in spring than in fall. This seasonal variation may have been related to a reduced nutritional status and impaired immune response of goats in spring. In conclusion, the high proportion of positive goats confirms the persistence of T. cruzi in rural Mendoza.

Effect of host and environment-related factors on fleas of the pichi, an armadillo from Argentina.

The pichi (Zaedyus pichiy; Cingulata: Chlamyphoridae) is an armadillo whose ectoparasite fauna is composed of ticks and fleas. Fleas were collected from 218 pichis in southern Mendoza, Argentina, in summer and winter of 2015 and 2016. Prevalences were analyzed and differences in the intensities of the total number of fleas related to host (age, sex, weight, size and physical condition) and environment-related (seasonality and year) factors evaluated. Phthiropsylla agenoris was the only species found. Intensities of fleas were higher in 2015, in juveniles, and in males. Individuals with poor physical condition were more parasitized than those with good or normal body condition. The main explanatory variable was sampling year. This factor was directly associated with precipitation. The extreme conditions and heavy rains during the El Niño event in 2015/2016 led to environmental changes that seem to have severely affected the life cycle of fleas.

Ecosystem services provided by armadillos.

Awareness of the natural ecological processes provided by organisms that benefit human well-being has significantly progressed towards the goal of making conservation a mainstream value. Identifying different services and the species that provide them is a vital first step for the management and maintenance of these so-called ecosystem services. Herein, we specifically address the armadillos, which play key functional roles in terrestrial ecosystems, including as ecosystem engineers, predators, and vectors of invertebrates and nutrients, although these roles have often been overlooked. Armadillos can control pests, disperse seeds, and be effective sentinels of potential disease outbreaks or bioindicators of environmental contaminants. They also supply important material (meat, medicines) and non-material (learning, inspiration) contributions all over the Americas. We identify key gaps in the understanding of ecosystem services provided by armadillos and areas for future research required to clarify their functional role in terrestrial ecosystems and the services they supply. Such information will produce powerful arguments for armadillo conservation.

Characterization and correlations of behavioral and adrenocortical activities of zoo-housed lesser anteaters (Tamandua tetradactyla).

We characterized behavioral and adrenocortical activities of Tamandua tetradactyla under human care driven by the hypothesis that they vary between males and females. We also assessed the potential association between natural or abnormal behaviors and adrenocortical activity. We kept females and males T. tetradactyla in individual, contiguous enclosures at Córdoba Zoo (Argentina), under natural photoperiod and temperature. During 29 consecutive days we monitored the animals' behavior by recording their activity pattern every 5 min using infrared cameras (8352 records/individual). We collected all feces and measured fecal glucocorticoid metabolites (FGM) with an 11-oxoaetiocholanolone enzyme immunoassay. We found individual differences in all behavioral variables. We detected that females exhibited lower total activity than males (23.8 ± 0.2% and 32.3 ± 0.3%, respectively; p = .005). Females were more active at night and males during the day (p < .05) and exhibited less abnormal behaviors than males (p = .05). Although we did not find sex-related differences for average FGM, we detected individual differences (p < .0001). We found that daily FGM showed negative (-0.39) and positive (0.38) correlations with natural and abnormal behaviors, respectively (p < .0001). Thus, we consider that individual input and sex are factors to be considered in stress responses of the species in captivity. Natural and abnormal behaviors may demand different levels of adrenocortical activity. Our findings may prove useful as normative data for ex situ management of conservation programs.

Behavioral responses of three armadillo species (Mammalia: Xenarthra) to an environmental enrichment program in Villavicencio, Colombia.

Enrichment is a powerful tool to improve the welfare of animals under human care. Stress-related health and behavioral problems, as well as reproductive failure, are frequent in armadillos (Xenarthra, Cingulata, Dasypodidae) under human care, which hinders the development of successful ex situ conservation programs. Nevertheless, scientific studies on the effect of enrichment programs on armadillos are virtually non-existent. The objective of this study was to assess the impact of an enrichment program on the behavior of armadillos under human care. The behavior of 12 individuals of three species (Dasypus novemcinctus, D. sabanicola, and Cabassous unicinctus) maintained at Finca El Turpial, Villavicencio, Colombia, was recorded using scan sampling during three daily time blocks of 2 hr each before (4 weeks) and after (4 weeks) implementing an enrichment program. Enrichment did not stimulate the armadillos to change or extend their activity period. In general, activity levels were low during the entire study, and virtually no activity was recorded in the morning in any species, neither without nor with enrichment. The latter did, however, improve welfare by reducing abnormal and increasing natural foraging behaviors. All species were attracted by artificial termite mounds. Dasypus spp. showed special interest in cardboard boxes with food, while Cabassous was mainly attracted to hollow plastic balls filled with food. Our results suggest that separate enrichment programs need to be developed for different armadillo species, and that they should be applied during the time of day at which they are most active. Zoo Biol. 35:304-312, 2016. © 2016 Wiley Periodicals, Inc.

Shotgun Mitogenomics Provides a Reference Phylogenetic Framework and Timescale for Living Xenarthrans.

Xenarthra (armadillos, sloths, and anteaters) constitutes one of the four major clades of placental mammals. Despite their phylogenetic distinctiveness in mammals, a reference phylogeny is still lacking for the 31 described species. Here we used Illumina shotgun sequencing to assemble 33 new complete mitochondrial genomes, establishing Xenarthra as the first major placental clade to be fully sequenced at the species level for mitogenomes. The resulting data set allowed the reconstruction of a robust phylogenetic framework and timescale that are consistent with previous studies conducted at the genus level using nuclear genes. Incorporating the full species diversity of extant xenarthrans points to a number of inconsistencies in xenarthran systematics and species definition. We propose to split armadillos into two distinct families Dasypodidae (dasypodines) and Chlamyphoridae (euphractines, chlamyphorines, and tolypeutines) to better reflect their ancient divergence, estimated around 42 Ma. Species delimitation within long-nosed armadillos (genus Dasypus) appeared more complex than anticipated, with the discovery of a divergent lineage in French Guiana. Diversification analyses showed Xenarthra to be an ancient clade with a constant diversification rate through time with a species turnover driven by high but constant extinction. We also detected a significant negative correlation between speciation rate and past temperature fluctuations with an increase in speciation rate corresponding to the general cooling observed during the last 15 My. Biogeographic reconstructions identified the tropical rainforest biome of Amazonia and the Guiana Shield as the cradle of xenarthran evolutionary history with subsequent dispersions into more open and dry habitats.

Serosurvey of Leptospira interrogans, Brucella abortus and Chlamydophila abortus infection in free-ranging giant anteaters (Myrmecophaga tridactyla) from Brazil / Inquérito sorológico de Leptospira interrogans, Brucella abortus e Chlamydophila abortus em tamanduás-bandeira (Myrmecophaga tridactyla) de vida livre no Brasil

A serological survey for antibodies against Leptospira interrogans, Brucella abortus, and Chlamydophila abortus was conducted in 21 clinically healthy, free-ranging giant ant- eaters (Myrmecophaga tridactyla) from Parque Nacional das Emas (Goiás State, Brazil; n=6), Parque Nacional da Serra da Canastra (Minas Gerais State, Brazil; n=9), and RPPN SESC Pantanal (Mato Grosso State, Brazil; n=6) between July 2001 and September 2006. Sera were screened for antibodies against 22 serovars of Leptospira interrogans with a microscopic agglutination test. Twelve tested positive for L. interrogansserovars sentot (n=5 in PN Emas, n=2 in PN Serra da Canastra), butembo (n=2 in PN Serra da Canastra), autumnalis, bataviae, and shermani/icterohaemorrhagiae(n=1 each in SESC Pantanal)One adult female tested positive for B. abortus with the buffered plate antigen test. All sera were negative for C. abortususing the complement fixation text. This is the first report of pathogens that may interfere with the reproduction and population dynamics of free-ranging giant anteaters.

Inquéritos sorológicos para detecção de anticorpos contra Leptospira interrogans, Brucella abortus, e Chlamydophila abortus foram realizados em 21 tamanduás-bandeira (Myrmecophaga tridactyla) de vida livre do Parque Nacional das Emas (Goiás, Brasil, n=6), o Parque Nacional da Serra da Canastra (Minas Gerais, Brasil, n=9) e RPPN SESC Pantanal (Mato Grosso, Brasil, n=6) entre julho de 2001 e setembro de 2006. Os sor os foram testados para anticorpos contra 22 sorotipos de Leptospira interrogans com um teste de aglutinação microscópica. Doze animais foram considerados positivos para L. interrogans sorovares sentot (n=5 em PN Emas, n=2 em PN Serra da Canastra), butembo (n=2 em PN Serra da Canastra), autumnalis, bataviae e shermani/icterohaemorrhagiae(n=1 para cada sorovar em SESC Pantanal). Uma fêmea adulta testou positivo para B. abortuscom o teste do antígeno tamponado. Todos os soros se mostraram negativos para C. abortusatravés do teste de fixação do complemento. Este é o primeiro relato de patógenos que podem interferir na dinâmica reprodutiva de populações de tamanduás em estado selvagem.

High proportion of cactus species threatened with extinction.

A high proportion of plant species is predicted to be threatened with extinction in the near future. However, the threat status of only a small number has been evaluated compared with key animal groups, rendering the magnitude and nature of the risks plants face unclear. Here we report the results of a global species assessment for the largest plant taxon evaluated to date under the International Union for Conservation of Nature (IUCN) Red List Categories and Criteria, the iconic Cactaceae (cacti). We show that cacti are among the most threatened taxonomic groups assessed to date, with 31% of the 1,478 evaluated species threatened, demonstrating the high anthropogenic pressures on biodiversity in arid lands. The distribution of threatened species and the predominant threatening processes and drivers are different to those described for other taxa. The most significant threat processes comprise land conversion to agriculture and aquaculture, collection as biological resources, and residential and commercial development. The dominant drivers of extinction risk are the unscrupulous collection of live plants and seeds for horticultural trade and private ornamental collections, smallholder livestock ranching and smallholder annual agriculture. Our findings demonstrate that global species assessments are readily achievable for major groups of plants with relatively moderate resources, and highlight different conservation priorities and actions to those derived from species assessments of key animal groups.

Molecular phylogenetics unveils the ancient evolutionary origins of the enigmatic fairy armadillos.

Fairy armadillos or pichiciegos (Xenarthra, Dasypodidae) are among the most elusive mammals. Due to their subterranean and nocturnal lifestyle, their basic biology and evolutionary history remain virtually unknown. Two distinct species with allopatric distributions are recognized: Chlamyphorus truncatus is restricted to central Argentina, while Calyptophractus retusus occurs in the Gran Chaco of Argentina, Paraguay, and Bolivia. To test their monophyly and resolve their phylogenetic affinities within armadillos, we obtained sequence data from modern and museum specimens for two mitochondrial genes (12S RNA [MT-RNR1] and NADH dehydrogenase 1 [MT-ND1]) and two nuclear exons (breast cancer 1 early onset exon 11 [BRCA1] and von Willebrand factor exon 28 [VWF]). Phylogenetic analyses provided a reference phylogeny and timescale for living xenarthran genera. Our results reveal monophyletic pichiciegos as members of a major armadillo subfamily (Chlamyphorinae). Their strictly fossorial lifestyle probably evolved as a response to the Oligocene aridification that occurred in South America after their divergence from Tolypeutinae around 32 million years ago (Mya). The ancient divergence date (∼17Mya) for separation between the two species supports their taxonomic classification into distinct genera. The synchronicity with Middle Miocene marine incursions along the Paraná river basin suggests a vicariant origin for pichiciegos by the disruption of their ancestral range. Their phylogenetic distinctiveness and rarity in the wild argue in favor of high conservation priority.

Husbandry of a pink fairy armadillo (Chlamyphorus truncatus): case study of a cryptic and little known species in captivity.

Pink fairy armadillos, Chlamyphorus truncatus, are poorly known fossorial mammals that are endemic to central Argentina. These smallest of all extant armadillos are rarely observed in the field and extremely difficult to maintain under captive conditions. This case study describes the husbandry of a male pink fairy armadillo that was maintained in an artificial environment for 8 months. A stable, undisturbed environment consisting of abundant compact sand and hiding places on the surface was the key to its successful maintenance. The artificial diet consisted of a semiliquid mixture of ground cat food, insectivore diet, mashed banana, vitamins, and minerals. Any slight modification to its environment or diet triggered a stress response.

Characterization of seasonal reproduction patterns in female pichis Zaedyus pichiy (Xenarthra: Dasypodidae) estimated by fecal sex steroid metabolites and ovarian histology.

Reproductive strategies vary considerably among species, but most studies have focused on a very limited number of mammalian species. Knowledge of the reproductive cycle and behavior is essential for developing and implementing in situ and ex situ conservation strategies for threatened and endangered species. This study aimed at characterizing the seasonal reproductive pattern of female pichis Zaedyus pichiy, a threatened small armadillo native to arid regions of Argentina and Chile, through direct observations, histological studies, and by measuring fecal immunoreactive estrogens, progestagens and glucocorticoids in 10 wild-born, captive pichis and in free-ranging individuals. Results suggest that pichis are seasonal breeders that give birth to one yearly litter of 1-2 offspring, which do not leave the burrow until they are weaned at approximately 37 days. Ovarian follicular growth seems to occur throughout the year. Fecal progestagen, estrogen and glucocorticoid concentrations were minimal during the first half of pregnancy, increased to peak concentrations of up to 3500, 200 and 200ng/g dry feces, respectively, and decreased before parturition. Postpartum progestagen concentrations were greater in lactating females than females that aborted or did not raise their offspring (p<0.0001), which is probably related to an elevated corticosteroid synthesis that contributes to maintain lactation, given that fecal glucocorticoid concentrations were of similar pattern. Observations of a second pregnancy after late abortion or death of the newborn litter and sustained follicular growth during pregnancy and lactation suggest that female pichis can become receptive briefly after having lost their litter. Fecal estrogen and progestagen concentrations of non-pregnant, non-lactating females did not have a well-defined hormonal cyclic pattern, and corpora lutea were only observed in pregnant females.

Health evaluation of free-ranging and captive pichis (Zaedyus pichiy; Mammalia, Dasypodidae), in Mendoza Province, Argentina.

The health of free-ranging and captive pichis (Zaedyus pichiy) was assessed in Mendoza Province, Argentina, between November 2001 and December 2006. Postmortem examinations of 150 confiscated and vehicle-killed pichis and clinical examinations of 139 wild-caught individuals suggest that the wild populations are currently in good health. Lesions and scars were observed in a large proportion of wild-caught pichis. The most common lesions were associated with parasitism or parasite larva migration. Sarcocystis cysts were relatively common in the skeletal muscle, and Besnoitia cysts were observed in the lungs of 24 evaluated animals. Elevated ambient humidity levels often caused moist dermatitis with epidermal detachment in captive pichis. This report constitutes the first health evaluation of free-ranging and captive Z. pichiy. It will be a starting point for future health studies and will be beneficial for the captive management of this species.

Seasonal reproduction in male pichis Zaedyus pichiy (Xenarthra: Dasypodidae) estimated by fecal androgen metabolites and testicular histology.

Poaching poses a threat to a wide variety of wildlife, and basic information about the biology of hunted species needs to be collected before their populations decline to the extent that requires drastic human intervention. As the survival of a species is related to its ability to reproduce, data on its reproductive cycle are necessary for the development of management strategies. The hypothesis was tested that the reproductive season of pichis (Zaedyus pichiy), small hibernating armadillos that inhabit arid environments in Argentina and Chile, is limited to spring months. Gonadal competence of semi-captive and wild-caught male pichis of Mendoza Province, Argentina was studied, by measuring fecal immunoreactive testosterone concentrations and evaluating spermatogenic activity. Results suggest that Z. pichiy is a seasonal breeder that regulates reproduction through photoperiodic cues. Gonadal competence was limited to a period of 3-5 months in spring and early summer and was reflected in enlarged testes, increased spermatogenesis, and significantly elevated fecal immunoreactive testosterone concentrations. The reproductive season for males from southern Mendoza was almost 6 weeks shorter than in the north. This fact, along with significant morphological differences between both groups, suggests that northern and southern pichis belong to two distinct populations. It is concluded that prolonged breeding seasons and more favorable environmental conditions in northern Mendoza favor a prolongation of the reproductive season that may allow pichis to breed later in the year, thus maximizing reproductive opportunities.

Hematology and serum chemistry values in captive and wild pichis, Zaedyus pichiy (Mammalia, Dasypodidae).

As part of an ongoing study on the health status of pichis, Zaedyus pichiy (Mammalia, Dasypodidae), blood was collected under manual restraint from 72 free-ranging pichis captured in Mendoza Province, Argentina, between November 2001 and December 2006, and from 22 captive-kept pichis in January 2007. Reference values were established for hematology and serum chemistry. Pichis had lower leukocyte counts and higher mean corpuscular volumes than most other mammals. Blood values were similar for captive and wild pichis, and only a few significant differences were found among genders or age classes.

Hibernation and daily torpor in an armadillo, the pichi (Zaedyus pichiy).

Hibernation and daily torpor are physiological strategies to cope with energetic challenges that occur in many mammalian and avian taxa, but no reliable information exists about daily torpor or hibernation for any xenarthran. Our objective was to determine whether the pichi (Zaedyus pichiy), a small armadillo (Xenarthra, Dasypodidae) that inhabits arid and semi-arid habitats in central and southern Argentina and Chile, enters shallow daily torpor or prolonged deep hibernation during winter when environmental temperature and food availability are low. We studied body temperature changes during winter in semi-captive pichis by means of temperature dataloggers implanted subcutaneously. All individuals entered hibernation, characterized by torpor events of 75+/-20 h during which the subcutaneous temperature (T(sc)) decreased to 14.6+/-2.1 degrees C. These events were interrupted by periods of euthermia of 44+/-38 h with a T(sc) of 29.1+/-0.7 degrees C. After the hibernation season, daily torpor bouts of 4 to 6 h occurred irregularly, with T(sc) dropping to as low as 24.5 degrees C. We conclude that the pichi is a true hibernator and can enter daily torpor outside of the hibernation season.

Retroposed elements and their flanking regions resolve the evolutionary history of xenarthran mammals (armadillos, anteaters, and sloths).

Armadillos, anteaters, and sloths (Order Xenarthra) comprise 1 of the 4 major clades of placental mammals. Isolated in South America from the other continental landmasses, xenarthrans diverged over a period of about 65 Myr, leaving more than 200 extinct genera and only 31 living species. The presence of both ancestral and highly derived anatomical features has made morphoanatomical analyses of the xenarthran evolutionary history difficult, and previous molecular analyses failed to resolve the relationships within armadillo subfamilies. We investigated the presence/absence patterns of retroposons from approximately 7,400 genomic loci, identifying 35 phylogenetically informative elements and an additional 39 informative rare genomic changes (RGCs). DAS-short interspersed elements (SINEs), previously described only in the Dasypus novemcinctus genome, were found in all living armadillo genera, including the previously unsampled Chlamyphorus, but were noticeably absent in sloths. The presence/absence patterns of the phylogenetically informative retroposed elements and other RGCs were then compared with data from the DNA sequences of the more than 12-kb flanking regions of these retroposons. Together, these data provide the first fully resolved genus tree of xenarthrans. Interestingly, multiple evidence supports the grouping of Chaetophractus and Zaedyus as a sister group to Euphractus within Euphractinae, an association that was not previously demonstrated. Also, flanking sequence analyses favor a close phylogenetic relationship between Cabassous and Tolypeutes within Tolypeutinae. Finally, the phylogenetic position of the subfamily Chlamyphorinae is resolved by the noncoding sequence data set as the sister group of Tolypeutinae. The data provide a stable phylogenetic framework for further evolutionary investigations of xenarthrans and important information for defining conservation priorities to save the diversity of one of the most curious groups of mammals.