New records of fleas and ticks in armadillos (Xenarthra: Chlamyphoridae) br /from the Espinal and Monte ecoregions of La Pampa province, Argentina.

La Pampa province is divided into two clearly distinguishable fractions: a small northeastern humid sector corresponding to the Pampas ecoregion and a drier western sector, represented by the Monte de Llanuras y Mesetas (termed Monte region in this paper) and Espinal ecoregions (sensu Brown et al. 2006). These three ecoregions are visibly distinguishable from an edaphological and phytogeographic point of view, while the mammalian fauna composition is homogeneous. The study area was located in the central part of the province, comprising the Monte and Espinal ecoregions (Fig. 1). In that area three species of armadillos are recorded (Soibelzon et al. 2015). Two of these (Zaedyus pichiy Desmarest, 1804 and Chaetophractus villosus Desmarest, 1804) (Xenarthra: Chlamyphoridae) are the most common and widely distributed armadillos both in the province and in the country, while the third species, Chlamyphorus truncatus Harlan, 1825, has a more restricted distribution and is one of the most cryptic and least known armadillos in the country. For this reason, in our fieldwork ectoparasites were obtained only from the first two species mentioned.

Osteoderm microstructure of Riostegotherium yanei, the oldest Xenarthra.

Abstract: Riostegotherium yanei from the Itaboraí Basin, Brazil, is the oldest known Xenarthra. This paper aims to describe the internal morphology of the osteoderms of Riostegotherium yanei from the perspective of histology and micro-CT approaches, expanding the available data on cingulate osteoderm microstructure. Seven osteoderms of R. yanei were used for the internal microstructure description and eight of Dasypus novemcinctus for comparison. The osteoderms of Riostegotherium yanei lacks the diploë-like structure typical of glyptodonts but has a three-layered structure composed of two layers of non-Haversian compact bone enclosing a central layer of primary and secondary osteons. This internal organization is distinct from other Astegotheriini of comparable age, but similar to Dasypus. The 3D reconstruction of Riostegotherium yanei revealed two patterns of internal organization. Pattern 1 of movable osteoderm is composed of large remodeled areas at the base and a more compact bone at the tongue; in Pattern 2 (both movable and buckler), the internal cavities are much smaller, more numerous, and more interconnected to each other. In one buckler osteoderm, the cavities are organized somewhat radially with a compact central region (Pattern 1). Pattern 1 of both movable and buckler osteoderms resemble that of Dasypus.

A review of the Quaternary Scelidotheriinae (Mammalia, Xenarthra, Tardigrada) from the Tarija-Padcaya basin, Bolivia.

The Mylodontidae Scelidotheriinae (Mammalia, Xenarthra, Tardigrada) are a diversified clade of South American fossil ground sloths, with a wide geographic distribution, especially in high and middle latitudes. According to the last revision, the Quaternary diversity includes the genera Scelidotherium, Catonyx, and Valgipes. The clade Scelidotheriinae is well represented in the Pleistocene of the Tarija-Padcaya basin, and the first mention of these ground sloths correspond to the middle of the XIX Century. Since then, several species (i.e., Scelidotherium tarijensis, Scelidodon tarijensis, Scelidotherium capellini) have been reported as inhabiting the Tarija-Padcaya basin during the Pleistocene. Despite the abundance of fossil records of Scelidotheriinae in this area, no modern taxonomic revisions are available. In consequence, in this contribution a revision of the remains assigned to Scelidotheriinae from the Tarija-Padcaya basin is accomplished, and some biostratigraphic and geographic implications are discussed. Our results show that one single species (Catonyx tarijensis) can be recognized in the studied area, whereas a supposed smaller one (Scelidotherium patrium) actually corresponds to juvenile specimens of C. tarijensis.

Functional morphology and paleoecology of Pilosa (Xenarthra, Mammalia) based on a two-dimensional geometric Morphometrics study of the Humerus.

The relationship between humerus shape and the modes of exploring substrate among extinct and extant Pilosa (especially anteaters and ground sloths) were investigated here. We used geometric morphometrics and discriminant analyses to relate morphological patterns and their possible ecological categories. Our results suggest that plesiomorphic taxa such as Nothrotheriidae, most Megalonychidae and basal Megatheriidae tend to have more slender humerus, associated to generalist habitus (climbing, swimming and digging activities), and while Mylodontidae developed specialized digging habitus. Additionally, we inferred ground sloths which inhabited the Brazilian territory during the Quaternary likely occupied at least four different niches. Mammals display morphofunctional adaptations on the limbs which are reflected on their modes of substrate exploration. Herein, we analyzed the humerus morphology of ground sloths and anteaters. Our results suggest that most of the Pleistocene Mylodonts were fossorial taxa, while most of the Santacrucian sloths plus extant anteaters were semiarboreal or semiaquatic taxa. The Pleistocene Megatheriidae should be ambulatory.

Resolving the phylogenetic position of Darwin's extinct ground sloth (Mylodon darwinii) using mitogenomic and nuclear exon data.

Mylodon darwinii is the extinct giant ground sloth named after Charles Darwin, who first collected its remains in South America. We have successfully obtained a high-quality mitochondrial genome at 99-fold coverage using an Illumina shotgun sequencing of a 12 880-year-old bone fragment from Mylodon Cave in Chile. Low level of DNA damage showed that this sample was exceptionally well preserved for an ancient subfossil, probably the result of the dry and cold conditions prevailing within the cave. Accordingly, taxonomic assessment of our shotgun metagenomic data showed a very high percentage of endogenous DNA with 22% of the assembled metagenomic contigs assigned to Xenarthra. Additionally, we enriched over 15 kb of sequence data from seven nuclear exons, using target sequence capture designed against a wide xenarthran dataset. Phylogenetic and dating analyses of the mitogenomic dataset including all extant species of xenarthrans and the assembled nuclear supermatrix unambiguously place Mylodon darwinii as the sister-group of modern two-fingered sloths, from which it diverged around 22 million years ago. These congruent results from both the mitochondrial and nuclear data support the diphyly of the two modern sloth lineages, implying the convergent evolution of their unique suspensory behaviour as an adaption to arboreality. Our results offer promising perspectives for whole-genome sequencing of this emblematic extinct taxon.

Phylogenetic relationship and molecular dating of Indian pangolin (Manis crassicaudata) with other extant pangolin species based on complete cytochrome b mitochondrial gene.

Pangolins are a group of eight endangered mammalian species included in the family Manidae (Order Pholidota) and divided into four each African (Arboreal species; Phataginus tetradactyla, Phataginus tricuspis, Ground dwelling species; Smutsia gigantea and Smutsia temminckii) and Asian (Ground dwelling; Manis crassicaudata, Manis pentadactyla, Manis javanica and Manis culionensis) species. The taxonomy of all the eight extant pangolin species based on molecular genetics studies, remains unresolved and poorly examined. The present study is to address this lacuna by studying the phylogenetic, taxonomic status and molecular dating of Indian pangolin with other six out of eight extant pangolins (Sunda pangolin possibly extinct) based on complete coding region of mitochondrial cytochrome b gene. Overall sequences divergence among pangolins ranged between 0.01 ± 0.01 and 0.26 ± 0.03, where within 'Manis' it ranged between 0.01 ± 0.01 and 0.14 ± 0.03. Cytochrome b sequences based phylogenetic tree revealed, the division of seven pangolin species into two paraphyletic clades of African and Asian species, further these two paraphyletic clades were divided into three well-supported monophyletic clades, first for the genus 'Smutsia' with two African ground pangolins, second for the genus 'Phataginus' with two African arboreal pangolins and third for 'Manis' with three Asian species. Within clade of 'Manis', Chinese pangolin and Malayan pangolin are basal where Indian pangolin is present as a sister clade and furthermore, molecular dating analysis suggested that pangolins diverged from Carnivora at ∼87.2 MYA, followed by the split of Asian pangolins and African pangolins at ∼36.1 MYA and Indian pangolin split from Chinese pangolin and Malayan pangolin at ∼16.7 MYA.

Phylogenetic and functional implications of the ear region anatomy of Glossotherium robustum (Xenarthra, Mylodontidae) from the Late Pleistocene of Argentina.

Several detailed studies of the external morphology of the ear region in extinct sloths have been published in the past few decades, and this anatomical region has proved extremely helpful in elucidating the phylogenetic relationships among the members of this mammalian clade. Few studies of the inner ear anatomy in these peculiar animals were conducted historically, but these are increasing in number in recent years, in both the extinct and extant representatives, due to wider access to CT-scanning facilities, which allow non-destructive access to internal morphologies. In the present study, we analyze the extinct ground sloth Glossotherium robustum and provide a description of the external features of the ear region and the endocranial side of the petrosal bone, coupled with the first data on the anatomy of the bony labyrinth. Some features observable in the ear region of G. robustum (e.g., the shape and size of the entotympanic bone and the morphology of the posteromedial surface of the petrosal) are highly variable, both intraspecifically and intraindividually. The form of the bony labyrinth of G. robustum is also described, providing the first data from this anatomical region for the family Mylodontidae. The anatomy of the bony labyrinth of the genus Glossotherium is here compared at the level of the superorder Xenarthra, including all available extant and extinct representatives, using geometric morphometric methods. In light of the new data, we discuss the evolution of inner ear anatomy in the xenarthran clade, and most particularly in sloths, considering the influence of phylogeny, allometry, and physiology on the shape of this highly informative region of the skull. These analyses show that the inner ear of Glossotherium more closely resembles that of the extant anteaters, and to a lesser extent those of the giant ground sloth Megatherium and euphractine armadillos, than those of the extant sloths Bradypus and Choloepus, further demonstrating the striking morphological convergence between the two extant sloth genera.

The Complete Phylogeny of Pangolins: Scaling Up Resources for the Molecular Tracing of the Most Trafficked Mammals on Earth.

Pangolins, considered the most-trafficked mammals on Earth, are rapidly heading to extinction. Eight extant species of these African and Asian scale-bodied anteaters are commonly recognized, but their evolutionary relationships remain largely unexplored. Here, we present the most comprehensive phylogenetic assessment of pangolins, based on genetic variation of complete mitogenomes and 9 nuclear genes. We confirm deep divergence among Asian and African pangolins occurring not later than the Oligocene-Miocene boundary ca. 23 million years ago (Ma) (95% HPD = 18.7-27.2), limited fossil evidence suggesting dispersals from Europe. We recognize 3 genera including Manis (Asian pangolins), Smutsia (large African pangolins), and Phataginus (small African pangolins), which first diversified in the Middle-Upper Miocene (9.8-13.3 Ma) through a period of gradual cooling coinciding with a worldwide taxonomic diversification among mammals. Based on large mitogenomic distances among the 3 genera (18.3-22.8%) and numerous (18) morphological traits unique to Phataginus, we propose the subfamily Phatagininae subfam. nov. to designate small African pangolins. In contrast with the morphological-based literature, our results establish that the thick-tailed pangolin (Manis crassicaudata) is sister-species of the Sunda (Manis javanica) and Palawan (Manis culionensis) pangolins. Mitogenomic phylogenetic delineations supported additional pangolin species subdivisions (n = 13), including 6 African common pangolin (Phataginus tricuspis) lineages, but these patterns were not fully supported by our multi-locus approach. Finally, we identified more than 5000 informative mitogenomic sites and diagnostic variation from 5 nuclear genes among all species and lineages of pangolins, providing an important resource for further research and for effectively tracing the worldwide pangolin trade.

Orientation of the lateral semicircular canal in Xenarthra and its links with head posture and phylogeny.

The orientation of the semicircular canals of the inner ear in the skull of vertebrates is one of the determinants of the capacity of this system to detect a given rotational movement of the head. Past functional studies on the spatial orientation of the semicircular canals essentially focused on the lateral semicircular canal (LSC), which is supposedly held close to horizontal during rest and/or alert behaviors. However, they generally investigated this feature in only a few and distantly related taxa. Based on 3D-models reconstructed from µCT-scans of skulls, we examined the diversity of orientations of the LSC within one of the four major clades of placental mammals, that is, the superorder Xenarthra, with a data set that includes almost all extant genera and two extinct taxa. We observed a wide diversity of LSC orientations relative to the basicranium at both intraspecific and interspecific scales. The estimated phylogenetic imprint on the orientation of the LSC was significant but rather low within the superorder, though some phylogenetic conservatism was detected for armadillos that were characterized by a strongly tilted LSC. A convergence between extant suspensory sloths was also detected, both genera showing a weakly tilted LSC. Our preliminary analysis of usual head posture in extant xenarthrans based on photographs of living animals further revealed that the LSC orientation in armadillos is congruent with a strongly nose-down head posture. It also portrayed a more complex situation for sloths and anteaters. Finally, we also demonstrate that the conformation of the cranial vault and nuchal crests as well as the orientation of the posterior part of the petrosal may covary with the LSC orientation in Xenarthra. Possible inferences for the head postures of extinct xenarthrans such as giant ground sloths are discussed in the light of these results.

Regarding the real diversity of Glyptodontidae (Mammalia, Xenarthra) in the late Pliocene (Chapadmalalan Age/Stage) of Argentina.

A large diversity of Glyptodontidae has been proposed as characterizing the Chapadmalalan Age (Pliocene). Most of these taxa were recognized on the basis of partial dorsal carapaces and/or caudal tubes, whereas the main diagnostic characteristic is a particular morphology of the exposed surface of the osteoderms. From a biostratigraphic point of view some species are biostratigraphically important. The Upper Chapadmalalan is based on the Paraglyptodon chapadmalensis biozone. Both the re-evaluation of the type and referred materials and new significant findings from the Chapadmalal and El Polvorín Formations indicate that the diversity of Pliocene Glyptodontidae is more limited than previously supposed. The particular morphology of the exposed surface of the osteoderms that characterizes some of the species actually corresponds to a taphonomic alteration, which results in a non-real ornamentation pattern. Thus, the Glyptodontinae P. chapadmalensis must be replaced as a fossil guide because neither this species nor the species included in the genera Urotherium, Trachycalyptus and Lomaphorus are well characterized. Taking into account the diversity of Glyptodontidae for this lapse, the Glyptodontinae are very scarce (a situation that contrasts with its records in the Pleistocene), whereas Eosclerocalyptus, "Plohophorini" (Plohophorus) and Doedicurinae (cf. Eleutherocercus antiquus) are among the most recorded taxa.

Finding the right coverage: the impact of coverage and sequence quality on single nucleotide polymorphism genotyping error rates.

Restriction-enzyme-based sequencing methods enable the genotyping of thousands of single nucleotide polymorphism (SNP) loci in nonmodel organisms. However, in contrast to traditional genetic markers, genotyping error rates in SNPs derived from restriction-enzyme-based methods remain largely unknown. Here, we estimated genotyping error rates in SNPs genotyped with double digest RAD sequencing from Mendelian incompatibilities in known mother-offspring dyads of Hoffman's two-toed sloth (Choloepus hoffmanni) across a range of coverage and sequence quality criteria, for both reference-aligned and de novo-assembled data sets. Genotyping error rates were more sensitive to coverage than sequence quality and low coverage yielded high error rates, particularly in de novo-assembled data sets. For example, coverage ≥5 yielded median genotyping error rates of ≥0.03 and ≥0.11 in reference-aligned and de novo-assembled data sets, respectively. Genotyping error rates declined to ≤0.01 in reference-aligned data sets with a coverage ≥30, but remained ≥0.04 in the de novo-assembled data sets. We observed approximately 10- and 13-fold declines in the number of loci sampled in the reference-aligned and de novo-assembled data sets when coverage was increased from ≥5 to ≥30 at quality score ≥30, respectively. Finally, we assessed the effects of genotyping coverage on a common population genetic application, parentage assignments, and showed that the proportion of incorrectly assigned maternities was relatively high at low coverage. Overall, our results suggest that the trade-off between sample size and genotyping error rates be considered prior to building sequencing libraries, reporting genotyping error rates become standard practice, and that effects of genotyping errors on inference be evaluated in restriction-enzyme-based SNP studies.

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.

Reassessment of the hairy long-nosed armadillo "Dasypus" pilosus (Xenarthra, Dasypodidae) and revalidation of the genus Cryptophractus Fitzinger, 1856.

The hairy long-nosed armadillo, currently referred as Dasypus (Cryptophractus) pilosus, is an enigmatic species endemic to montane cloud forests and subparamo of Peruvian Andes. Its strikingly different external features, which include the carapace concealed by abundant hair, the presence of more movable bands, and a slender skull, have raised questions regarding its taxonomic status as subgenus or as genus. This paper assesses this issue based on a cladistic study and provides a detailed comparative description of the species, including the first account on the distinctive ornamentation of its osteoderms. Based on several unique characters in the carapace, skull, mandible, and teeth, as well as on the external phylogenetic position relative to other Dasypus, we favor the assignment of the hairy long-nosed armadillo to other genus. As result, we revalidate the original generic epithet, so that the valid name of the species is Cryptophractus pilosus Fitzinger, 1856.

On the fossil remains of Panochthus Burmeister, 1866 (Xenarthra, Cingulata, Glyptodontidae) from the Pleistocene of southern Brazil.

The genus Panochthus represents the last lineage of "Panochthini" recorded in the Pleistocene. This genus has a wide latitudinal distribution in South America, and in Brazil it occurs in the southern and northeastern regions. In this paper we describe new material (isolated osteoderms and caudal tube fragments) assigned to Panochthus from the state of Rio Grande do Sul (southern Brazil) and discuss some taxonomic issues related to Panochthus tuberculatus and Panochthus greslebini based on this material . The occurrence of P. greslebini is the first for outside the Brazilian Intertropical Region. In addition, we describe new diagnostic features to differentiate the osteoderms of P. greslebini and P. tuberculatus. Unfortunately, it was not possible to identify some osteoderms at the species level. Interestingly, they showed four distinct morphotypes characterized by their external morphology, and thus were attributed to Panochthus sp. Lastly, we conclude that in addition to P.tuberculatus registered to southern Brazil, there is another species of the genus, assignable to P. cf. P. greslebini. Our analysis reinforce the reliability of caudal tube characters for the classification of species of Panochthus.

The Dasypodidae (Mammalia, Xenarthra) from the Urso Fóssil Cave (Quaternary), Parque Nacional de Ubajara, State of Ceará, Brazil: paleoecological and taxonomic aspects.

This paper deals with xenarthrans osteoderms assigned to Dasypus aff. D. novemcinctus, Euphractus sexcinctus and Cabassous sp. The material was collected in subsurface, from 0.10 to 0.60 m in the Urso Fóssil Cave, Parque Nacional de Ubajara, State of Ceará, northeastern Brazil. The ages of sediment samples from levels 4 and 5 (depths of 0.40 and 0.50 m) were determined by thermoluminescence technique, and indicated ages of 8,000 and 8,200 years BP for each layer respectively. The presence in these layers of early Holocene xenarthrans taxa can contribute to the understanding of the biotic evolution of the northwest region of Ceará during the last 10,000 years. Two of the three identified taxa still occur in the region: Dasypus novemcinctus and Euphractus sexcinctus. The Dasypodidae fauna here reported includes animals with generalist feeding habits and current wide geographical distribution. It is suggested, therefore, that the climatic and environmental conditions in the early Holocene were very similar the actual ones, and that the absence of Cabassous may be conditioned to other factors, such as anthropogenic action and loss of habitat by fragmentation of the vegetation.

Dextrocardia with situs solitus and inversion apex-basis axis in lesser anteater (Tamandua tetradactyla): case report / Dextrocardia com situs solitus e inversão de eixo ápice-base em tamanduá-mirim (Tamandua tetradactyla): relato de caso

Dextrocardia is a rare cardiac anomaly where the heart is situated on the right antimeres of the thorax. This study had the objective of describing a case of dextrocardia with situs solitus and apex-basis axis inversion in a lesser anteater (Tamandua tetradactyla) between five evaluated animals, all from the area of Mine Bauxite - Paragominas - Para. The arterial system was filled with contrasted latex and the animals were fixed with 10% formaldehyde and a posterior dissection was done. The heart of an animal was found in right antimere with inversion of the base-apex axis. The right atrium was more developed then the left and the pulmonary veins arrived directly in the left ventricle. The main vases of the base were identified with some topographic alterations resulting in: aorta dorsal to the cava caudal vein, pulmonary artery dorsal and cranial to aorta, pulmonary veins ventral to the pulmonary artery, cava caudal vein in ventral plain and cava cranial vein in dorsal plan in relation to the other vessels. Internally there were four cardiac chambers, with absence of septal communication.

Dextrocardia é uma anomalia cardíaca rara no qual o coração está situado no antímero direito do tórax. Este estudo objetivou descrever um caso de dextrocardia com situs solitus e inversão do eixo ápice-base em um tamanduá-mirim (Tamandua tetradactyla), entre cinco animais avaliados, sendo todos da área da mina de bauxita - Paragominas - Pará. O sistema arterial foi preenchido com látex contrastado e os animais foram fixados com formol a 10% e seguido de dissecção posterior. O coração de um dos animais foi encontrado no antímero direito com inversão do eixo ápice-base. O átrio direito era mais desenvolvido do que o esquerdo e as veias pulmonares chegaram direto no ventrículo esquerdo. Foram identificados os principais vasos da base com alterações topográficas, resultando em: aorta dorsal à veia cava caudal, artéria pulmonar dorsal e cranial da aorta, veias pulmonares ventrais a artéria pulmonar, veia cava caudal em plano ventral e veia cava cranial em plano dorsal em relação a outros vasos. Internamente foram localizadas quatro câmaras cardíacas, com ausência de comunicação septal.

Finite Element Analysis of the Cingulata Jaw: An Ecomorphological Approach to Armadillo's Diets.

Finite element analyses (FEA) were applied to assess the lower jaw biomechanics of cingulate xenarthrans: 14 species of armadillos as well as one Pleistocene pampathere (11 extant taxa and the extinct forms Vassallia, Eutatus and Macroeuphractus). The principal goal of this work is to comparatively assess the biomechanical capabilities of the mandible based on FEA and to relate the obtained stress patterns with diet preferences and variability, in extant and extinct species through an ecomorphology approach. The results of FEA showed that omnivorous species have stronger mandibles than insectivorous species. Moreover, this latter group of species showed high variability, including some similar biomechanical features of the insectivorous Tolypeutes matacus and Chlamyphorus truncatus to those of omnivorous species, in agreement with reported diets that include items other than insects. It remains unclear the reasons behind the stronger than expected lower jaw of Dasypus kappleri. On the other hand, the very strong mandible of the fossil taxon Vassallia maxima agrees well with the proposed herbivorous diet. Moreover, Eutatus seguini yielded a stress pattern similar to Vassalia in the posterior part of the lower jaw, but resembling that of the stoutly built Macroeuphractus outesi in the anterior part. The results highlight the need for more detailed studies on the natural history of extant armadillos. FEA proved a powerful tool for biomechanical studies in a comparative framework.

Historical and non-invasive samples: a study case of genotyping errors in newly isolated microsatellites for the lesser anteater (Tamandua tetradactyla L., Pilosa).

Tamandua tetradactyla (Pilosa), the lesser anteater, is a medium-size mammal from South America. Its wide distribution through different landscapes, solitary and nocturnal habits, and the difficulty to capture and contain specimens limit the amount of individuals and populations sampled during fieldworks. These features along with the lack of specific molecular markers for the lesser anteater might be the causes for paucity in population genetic studies for the species. Historical samples from museum specimens, such as skins, and non-invasive samples, such as plucked hair, can be supplementary sources of DNA samples. However, the DNA quantity and quality of these samples may be limiting factors in molecular studies. In this study, we describe nine microsatellite loci for T. tetradactyla and test the amplification success, data reliability and estimate errors on both historical and non-invasive sample sets. We tested nine polymorphic microsatellites and applied the quality index approach to evaluate the relative performance in genotype analysis of 138 historical samples (study skin) and 19 non-invasive samples (plucked hair). The observed results show a much superior DNA quality of non-invasive over historical samples and support the quality index analysis as a practical tool to exclude samples with doubtful performance in genetic studies. We also found a relationship between the age of non-invasive samples and DNA quality, but lack of evidence of this pattern for historical samples.

Estudo anatômico do plexo lombossacral de Tamandua tetradactyla / Anatomical study of the lumbosacral plexus of the Tamandua tetradactyla

O tamanduá-mirim (Tamandua tetradactyla) é um xenartro da família Myrmecophagidae, encontrado da Venezuela ao sul do Brasil. Estudos apontam que essa é uma das espécies de animais selvagens mais vitimadas em número de atropelamentos, e, muitas vezes, o atendimento clínico adequado aos indivíduos feridos é dificultado pela carência de informações acerca dos mesmos. Visando contribuir com o conhecimento dessa espécie, este estudo teve como objetivo descrever seu plexo lombossacral. Para tanto, foram utilizados quatro cadáveres de Tamandua tetradactyla adultos e de ambos os sexos. O plexo lombossacral dessa espécie é formado pelos ramos ventrais dos nervos espinhais T18, L1, L2, L3, S1, S2, S3, S4, S5. Os nervos integrantes do plexo lombossacral do T. tetradactyla com suas formações mais frequentes foram os seguintes: genitofemoral (T18), cutâneo femoral lateral (T18-L1), femoral (T18, L1-L3), obturador (T18, L1-L3), glúteo cranial (L3-S1), isquiático (L3-S3), pudendo (S3-S4 ou S4-S5), retal caudal (S4 ou S5) e cutâneo femoral caudal (S4-S5). O plexo lombar e sacral dessa espécie é unido, sendo L3 o ponto de união entre eles. Devido ao pequeno número de vértebras lombares, a composição dos nervos do plexo lombossacral do T. tetradactyla apresenta características peculiares que se diferem das características das demais espécies já estudadas, quais sejam, a ausência dos nervos ílio-hipogástrico e ilioinguinal e participação de nervos torácicos na composição dos nervos do plexo lombar, presença de contribuição sacral na composição do nervo obturador e ausência de contribuição lombar na composição do nervo isquiático e um limite mais caudal na extensão do plexo sacral.

The lesser anteater (Tamandua tetradactyla) is a xenarthra of the Myrmecophagidae family found from Venezuela to southern Brazil. Studies have shown that this is one of the most numerous wildlife species victims of car collisions on roads, and often the appropriate clinical care to injured animals is hindered by the lack of information about them. In order to contribute to the knowledge of this species, this study aimed to describe its lumbosacral plexus. For this purpose, four cadavers of adult specimens of both sexes of T. tetradactyla were used. The lumbosacral plexus of the T. tetradactyla is formed by the ventral rami of spinal nerves T18, L1, L2, L3, S1, S2, S3, S4, S5. The lumbosacral plexus nerves with their most common formations in this species were as follows: genitofemoral (T18), lateral femoral cutaneous (T18-L1), femoral (T18, L1-L3), obturator (T18, L1-L3), cranial gluteal (L3-S1), ischiatic (L3-S3), pudendus (S3-S4 or S4-S5), caudal retal (S4 or S5), and caudal femoral cutaneous (S4-S5). The lumbar and sacral plexus of this species is joined, L3 being the link between them. Due to the small number of lumbar vertebrae, the arrangement of the lumbosacral plexus nerves of the T. tetradactyla showed peculiar characteristics that differ it from that of other previously studied species, such as the absence of iliohypogastric and ilioinguinal nerves and contribution of thoracic nerves in the formation of all the nerves of the lumbar plexus, presence of sacral contribution in the formation of the obturator nerve, and the lack of lumbar contribution for sciatic nerve formation and a most caudal extent of the sacral plexus.

Making the impossible possible: rooting the tree of placental mammals.

Untangling the root of the evolutionary tree of placental mammals has been nearly an impossible task. The good news is that only three possibilities are seriously considered. The bad news is that all three possibilities are seriously considered. Paleontologists favor a root anchored by Xenarthra (e.g., sloths and anteater), whereas molecular evolutionists have favored the two other possible roots: Afrotheria (e.g., elephants, hyraxes, and tenrecs) and Atlantogenata (Afrotheria + Xenarthra). Now, two groups of researchers have scrutinized the largest available genomic data sets bearing on the question and have come to opposite conclusions, as reported in this issue of Molecular Biology and Evolution. Needless to say, more research is needed.