Using genomic data to unravel the root of the placental mammal phylogeny.

Science.gov (United States)

Murphy, William J; Pringle, Thomas H; Crider, Tess A; Springer, Mark S; Miller, Webb

2007-04-01

The phylogeny of placental mammals is a critical framework for choosing future genome sequencing targets and for resolving the ancestral mammalian genome at the nucleotide level. Despite considerable recent progress defining superordinal relationships, several branches remain poorly resolved, including the root of the placental tree. Here we analyzed the genome sequence assemblies of human, armadillo, elephant, and opossum to identify informative coding indels that would serve as rare genomic changes to infer early events in placental mammal phylogeny. We also expanded our species sampling by including sequence data from >30 ongoing genome projects, followed by PCR and sequencing validation of each indel in additional taxa. Our data provide support for a sister-group relationship between Afrotheria and Xenarthra (the Atlantogenata hypothesis), which is in turn the sister-taxon to Boreoeutheria. We failed to recover any indels in support of a basal position for Xenarthra (Epitheria), which is suggested by morphology and a recent retroposon analysis, or a hypothesis with Afrotheria basal (Exafricoplacentalia), which is favored by phylogenetic analysis of large nuclear gene data sets. In addition, we identified two retroposon insertions that also support Atlantogenata and none for the alternative hypotheses. A revised molecular timescale based on these phylogenetic inferences suggests Afrotheria and Xenarthra diverged from other placental mammals approximately 103 (95-114) million years ago. We discuss the impacts of this topology on earlier phylogenetic reconstructions and repeat-based inferences of phylogeny.

Evolutionary history of LINE-1 in the major clades of placental mammals.

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Paul D Waters

2007-01-01

Full Text Available LINE-1 constitutes an important component of mammalian genomes. It has a dynamic evolutionary history characterized by the rise, fall and replacement of subfamilies. Most data concerning LINE-1 biology and evolution are derived from the human and mouse genomes and are often assumed to hold for all placentals.To examine LINE-1 relationships, sequences from the 3' region of the reverse transcriptase from 21 species (representing 13 orders across Afrotheria, Xenarthra, Supraprimates and Laurasiatheria were obtained from whole genome sequence assemblies, or by PCR with degenerate primers. These sequences were aligned and analysed.Our analysis reflects accepted placental relationships suggesting mostly lineage-specific LINE-1 families. The data provide clear support for several clades including Glires, Supraprimates, Laurasiatheria, Boreoeutheria, Xenarthra and Afrotheria. Within the afrotherian LINE-1 (AfroLINE clade, our tree supports Paenungulata, Afroinsectivora and Afroinsectiphillia. Xenarthran LINE-1 (XenaLINE falls sister to AfroLINE, providing some support for the Atlantogenata (Xenarthra+Afrotheria hypothesis.LINEs and SINEs make up approximately half of all placental genomes, so understanding their dynamics is an essential aspect of comparative genomics. Importantly, a tree of LINE-1 offers a different view of the root, as long edges (branches such as that to marsupials are shortened and/or broken up. Additionally, a robust phylogeny of diverse LINE-1 is essential in testing that site-specific LINE-1 insertions, often regarded as homoplasy-free phylogenetic markers, are indeed unique and not convergent.

Conservation of placentation during the tertiary radiation of mammals in South America

DEFF Research Database (Denmark)

Carter, Anthony Michael; Mess, Andrea Maria

2013-01-01

The eutherian placenta is considered to possess great plasticity, but it is not clear how this variation reflects adaptation to different ecological niches. Because South America was isolated for most of the Tertiary, it represents a natural laboratory to examine this question. We here describe...... placentation in three South American groups: Xenarthra have been part of the fauna from at least the mid-Paleocene whereas caviomorph rodents and Neotropical primates are each derived from a single founder that reached South America in the Eocene and Oligocene, respectively. The common ancestor of Xenarthra....... This pattern was present before arrival of these rodents in South America and enabled a successful radiation especially during the spread of grasslands. Neotropical primates have haemochorial, trabecular placentas with a specialized maternal blood supply; a pattern that contrasts with that of Old World monkeys...

Molecular decay of the tooth gene Enamelin (ENAM mirrors the loss of enamel in the fossil record of placental mammals.

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Robert W Meredith

2009-09-01

Full Text Available Vestigial structures occur at both the anatomical and molecular levels, but studies documenting the co-occurrence of morphological degeneration in the fossil record and molecular decay in the genome are rare. Here, we use morphology, the fossil record, and phylogenetics to predict the occurrence of "molecular fossils" of the enamelin (ENAM gene in four different orders of placental mammals (Tubulidentata, Pholidota, Cetacea, Xenarthra with toothless and/or enamelless taxa. Our results support the "molecular fossil" hypothesis and demonstrate the occurrence of frameshift mutations and/or stop codons in all toothless and enamelless taxa. We then use a novel method based on selection intensity estimates for codons (omega to calculate the timing of iterated enamel loss in the fossil record of aardvarks and pangolins, and further show that the molecular evolutionary history of ENAM predicts the occurrence of enamel in basal representatives of Xenarthra (sloths, anteaters, armadillos even though frameshift mutations are ubiquitous in ENAM sequences of living xenarthrans. The molecular decay of ENAM parallels the morphological degeneration of enamel in the fossil record of placental mammals and provides manifest evidence for the predictive power of Darwin's theory.

Manejo Clínico del Oso Palmero (Myrmecophaga tridactyla) bajo Condiciones de Cautiverio en el Bioparque Los Ocarros

OpenAIRE

Dora Adriana Lombo-Rodríguez

2008-01-01

El oso palmero (Myrmecophaga tridactyla. Linnaeus, 1758) es la única especie del género Myrmecophaga. Este mamífero se clasifica dentro del Infraorden: VERMILINGUA, Orden: XENARTHRA. Puede encontrarse en sabanas, pastizales, áreas inundadas y bosques húmedos. Geográficamente se encuentra al Norte desde Costa Rica hasta el Norte de Argentina. En Colombia en los Departamentos de Chocó, Magdalena, Orinoco, Amazonas y los Llanos Orientales....

Evolutionary Patterns of Bone Histology and Bone Compactness in Xenarthran Mammal Long Bones

OpenAIRE

Straehl, Fiona; Scheyer, Torsten; Forasiepi, Analia Marta; Macphee, Ross; Sanchez-Villagra, Marcelo

2015-01-01

Bone microstructure reflects physiological characteristics and has been shown to contain phylogenetic and ecological signals. Although mammalian long bone histology is receiving increasing attention, systematic examination of the main clades has not yet been performed. Here we describe the long bone microstructure of Xenarthra based on thin sections representing twenty-two species. Additionally, patterns in bone compactness of humeri and femora are investigated. The primary bone tissue of xen...

The evolution of armadillos, anteaters and sloths depicted by nuclear and mitochondrial phylogenies: implications for the status of the enigmatic fossil Eurotamandua.

OpenAIRE

Delsuc , Frédéric; Catzeflis , François ,; Stanhope , Michael ,; Douzery , Emmanuel ,

2001-01-01

The mammalian order Xenarthra (armadillos, anteaters and sloths) is one of the four major clades of placentals, but it remains poorly studied from the molecular phylogenetics perspective. We present here a study encompassing most of the order's diversity in order to establish xenarthrans' intra-ordinal relationships, discuss the evolution of their morphological characters, search for their extant sister group and specify the timing of their radiation with special emphasis on the status of the...

Morfologia, topografia e irrigação do coração do Tamandua tetradactyla

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Pinheiro,G.S.; Branco,É.; Pereira,L.C.; Lima,A.R.

2014-01-01

O Tamandua tetradactyla é uma espécie da ordem Xenarthra que apresenta coloração amarelada na cabeça, nos membros e na parte anterior do dorso, sendo o restante do corpo negro, formando uma espécie de colete, por isso também é chamado de "tamanduá-de-colete". Objetivou-se descrever a morfologia, a topografia e a irrigação cardíaca do Tamandua tetradactyla. Foram utilizados quatro espécimes jovens, provenientes da área de Mi...

The evolution of armadillos, anteaters and sloths depicted by nuclear and mitochondrial phylogenies: implications for the status of the enigmatic fossil Eurotamandua.

Science.gov (United States)

Delsuc, F; Catzeflis, F M; Stanhope, M J; Douzery, E J

2001-08-07

The mammalian order Xenarthra (armadillos, anteaters and sloths) is one of the four major clades of placentals, but it remains poorly studied from the molecular phylogenetics perspective. We present here a study encompassing most of the order's diversity in order to establish xenarthrans' intra-ordinal relationships, discuss the evolution of their morphological characters, search for their extant sister group and specify the timing of their radiation with special emphasis on the status of the controversial fossil Eurotamandua. Sequences of three genes (nuclear exon 28 of the Von Willebrand factor and mitochondrial 12S and 16S rRNAs) are compared for eight of the 13 living genera. Phylogenetic analyses confirm the order's monophyly and that of its three major lineages: armadillos (Cingulata), anteaters (Vermilingua) and sloths ('Tardigrada', renamed in 'Folivora'), and our results strongly support the grouping of hairy xenarthrans (anteaters and sloths) into Pilosa. Within placentals, Afrotheria might be the first lineage to branch off, followed by Xenarthra. The morphological adaptative convergence between New World xenarthrans and Old World pangolins is confirmed. Molecular datings place the early emergence of armadillos around the Cretaceous/Tertiary boundary, followed by the divergence between anteaters and sloths in the Early Eocene era. These Tertiary dates contradict the concept of a very ancient origin of modern xenarthran lineages. They also question the placement of the purported fossil anteater (Eurotamandua) from the Middle Eocene period of Europe with the Vermilingua and instead suggest the independent and convergent evolution of this enigmatic taxon.

Descrição anatômica das estruturas osteoarticulares do esqueleto axial do tatu-galinha (Dasypus novemcinctus Linnaeus, 1758) por meio da radiografia e tomografia computadorizada

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Alves, Lidiane da Silva [UNESP

2016-01-01

O tatu-galinha é um dos animais mais populosos da ordem Xenarthra com distribuição do sul dos Estados Unidos até a América do Sul. São animais frequentemente caçados e, em muitos casos, são vítimas de atropelamentos rodoviários. Existem diversos estudos descritivos sobre a fisiologia, a genética e o comportamento, porém a anatomia óssea e articular destes animais ainda é restrita. Este estudo tem por objetivo, descrever a anatomia das estruturas osteoarticulares do esqueleto axial em 20 tatus...

Muzzle of South American Pleistocene ground sloths (Xenarthra, Tardigrada).

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Bargo, M Susana; Toledo, Néstor; Vizcaíno, Sergio F

2006-02-01

Sloths are among the most characteristic elements of the Cainozoic of South America and are represented, during the Pleistocene, by approximately nine genera of gigantic ground sloths (Megatheriidae and Mylodontidae). A few contributions have described their masticatory apparatus, but almost no attention has been paid to the reconstruction of the muzzle, an important feature to consider in relation to food intake, and particularly relevant in sloths because of the edentulous nature of the muzzle and its varied morphology. The relationship between dietary habits and shape and width of the muzzle is well documented in living herbivores and has been considered an important feature for the inference of alimentary styles in fossils, providing an interesting methodological tool that deserves to be considered for xenarthrans. The goal of this study was to examine models of food intake by reconstructing the appearance and shape of the muzzle in five species of Pleistocene ground sloths (Megatherium americanum, Glossotherium robustum, Lestodon armatus, Mylodon darwini, and Scelidotherium leptocephalum) using reconstructions of the nasal cartilages and facial muscles involved in food intake. The preservation of the nasal septum, and the scars for muscular attachment in the rostral part of the skulls, allow making a conservative reconstruction of muzzle anatomy in fossil sloths. Wide-muzzled ground sloths (Glossotherium and Lestodon) had a square, nonprehensile upper lip and were mostly bulk-feeders. The lips, coupled with the tongue, were used to pull out grass and herbaceous plants. Narrow-muzzled sloths (Mylodon, Scelidotherium, and Megatherium) had a cone-shaped and prehensile lip and were mixed or selective feeders. The prehensile lip was used to select particular plants or plant parts. (c) 2005 Wiley-Liss, Inc.

A web-database of mammalian morphology and a reanalysis of placental phylogeny

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Asher Robert J

2007-07-01

Full Text Available Abstract Background Recent publications concerning the interordinal phylogeny of placental mammals have converged on a common signal, consisting of four major radiations with some ambiguity regarding the placental root. The DNA data with which these relationships have been reconstructed are easily accessible from public databases; access to morphological characters is much more difficult. Here, I present a graphical web-database of morphological characters focusing on placental mammals, in tandem with a combined-data phylogenetic analysis of placental mammal phylogeny. Results The results reinforce the growing consensus regarding the extant placental mammal clades of Afrotheria, Xenarthra, Euarchontoglires, and Laurasiatheria. Unweighted parsimony applied to all DNA sequences and insertion-deletion (indel characters of extant taxa alone support a placental root at murid rodents; combined with morphology this shifts to Afrotheria. Bayesian analyses of morphology, indels, and DNA support both a basal position for Afrotheria and the position of Cretaceous eutherians outside of crown Placentalia. Depending on treatment of third codon positions, the affinity of several fossils (Leptictis,Paleoparadoxia, Plesiorycteropus and Zalambdalestes vary, highlighting the potential effect of sequence data on fossils for which such data are missing. Conclusion The combined dataset supports the location of the placental mammal root at Afrotheria or Xenarthra, not at Erinaceus or rodents. Even a small morphological dataset can have a marked influence on the location of the root in a combined-data analysis. Additional morphological data are desirable to better reconstruct the position of several fossil taxa; and the graphic-rich, web-based morphology data matrix presented here will make it easier to incorporate more taxa into a larger data matrix.

Comparative aspects of trophoblast development and placentation

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Enders Allen C

2004-07-01

Full Text Available Abstract Based on the number of tissues separating maternal from fetal blood, placentas are classified as epitheliochorial, endotheliochorial or hemochorial. We review the occurrence of these placental types in the various orders of eutherian mammals within the framework of the four superorders identified by the techniques of molecular phylogenetics. The superorder Afrotheria diversified in ancient Africa and its living representatives include elephants, sea cows, hyraxes, aardvark, elephant shrews and tenrecs. Xenarthra, comprising armadillos, anteaters and sloths, diversified in South America. All placentas examined from members of these two oldest superorders are either endotheliochorial or hemochorial. The superorder Euarchontoglires includes two sister groups, Glires and Euarchonta. The former comprises rodents and lagomorphs, which typically have hemochorial placentas. The most primitive members of Euarchonta, the tree shrews, have endotheliochorial placentation. Flying lemurs and all higher primates have hemochorial placentas. However, the lemurs and lorises are exceptional among primates in having epitheliochorial placentation. Laurasiatheria, the last superorder to arise, includes several orders with epitheliochorial placentation. These comprise whales, camels, pigs, ruminants, horses and pangolins. In contrast, nearly all carnivores have endotheliochorial placentation, whilst bats have endotheliochorial or hemochorial placentas. Also included in Laurasiatheria are a number of insectivores that have many conserved morphological characters; none of these has epitheliochorial placentation. Consideration of placental type in relation to the findings of molecular phylogenetics suggests that the likely path of evolution in Afrotheria was from endotheliochorial to hemochorial placentation. This is also a likely scenario for Xenarthra and the bats. We argue that a definitive epitheliochorial placenta is a secondary specialization and that it

Tongue papillae morphology of brown-throated sloth Bradypus variegatus (SCHINZ, 1825

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D.M. Martins

2014-10-01

Full Text Available The Bradypus variegatus inhabits the forests of South America and feeds from leaves, branches and sprouts from different plants. Due to its diet and the lack of literature on the morphological aspect of Xenarthras, five Bradypus variegatus tongues from animals which died from natural causes were evaluated, and they came from Pará State Museum Emílio Goeldi and were donated to the Laboratory of Animal Morphological Research (LaPMA from UFRA, for revealing the different types of papillae and epithelial-connective tissue. Macroscopically, the tongues presented elongated shape, rounded apex, body, root, median sulcus in the root's apex, and two vallate papillae. The mucous membrane of the tongue revealed a keratinized stratified pavement epithelium, while the ventral surface of the tongue was thin and smooth, not provided with any type of papillae. However, the dorsal surface of the tongue was irregular with the presence of three types of papillae: filiform, fungiform and vallate papillae. The filiform papillae found were of a simple type, presenting a rounded base, irregularly distributed with a larger concentration and development on the tongue's apex and body. The fungiform papilla showed a practically smooth surface with irregular format, with the presence of gustatory pores; these were found all over the dorsal surface, with larger concentration at the rostral part of the apex. Only two vallate papillae were observed disposed in the root of the tongue, surrounded by a deep groove, and revealing several taste buds. The tongues from Bradypus variegatus presented gustatory papillae similar to the ones described for other Xenarthras species and wild mammals.

El registro más antiguo de Panochthus (Xenarthra, Glyptodontidae

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Zamorano, M.

2014-06-01

Full Text Available Panochthus is one of the largest sized and most frequently recorded genera of Pleistocene South American Glyptodontidae. A recent taxonomic revision shows that the genus includes six species: P. intermedius>/i> and P. subintermedius (early Pleistocene-middle Pleistocene, P. tuberculatus and P. frenzelianus (middle Pleistocene-late Pleistocene, whereas P. greslebini and P. jaguaribensis only can be referred to the Pleistocene sensu lato. In this contribution the oldest record of the genus Panochthus (MMP 5171 is presented and described. The remains came from the late Pliocene (Playa Los lobos Aloformation, Chapadmalal Formation; Chapadmalalan; Paraglyptodon chapalmalensis Biozone of the Mar del Plata, Buenos Aires province, Argentina. The material is represented by a considerable fragment of dorsal carapace and some associated osteoderms, which are assignable to an indeterminate species of Panochthus. One of the most significant characters in the exposed surface of the osteoderms is the presence of a clear “reticular” pattern, a character only observed in Panochthus. From a biostratigraphic viewpoint, it is remarkable the absence of records of Panochthus in the Marplatan Age/Stage (late Pliocene-early Pleistocene.Panochthus es uno de los géneros de gliptodóntidos de mayores dimensiones y más ampliamente registrado en el Pleistoceno del sur de América del Sur. Una reciente revisión demostró que alberga seis especies distribuidas cronológicamente de la siguiente manera: P. Intermedius y P. Subintermedius (Pleistoceno temprano-Pleistoceno medio, Ensenadense; P. Tuberculatus y P. Frenzelianus tienen sus biocrones limitados al Pleistoceno medio-Pleistoceno tardío (Bonaerense-Lujanense, mientras que P. Greslebini y P. Jaguaribensis solo pueden referirse al Pleistoceno sensu lato. En la presente contribución se da a conocer el registro más antiguo de Panochthus, representado por el material MMP 5171, procedente del Plioceno tardío (Aloformación Playa Los Lobos, Formación Chapadmalal; Chapadmalalense; Biozona de Paraglyptodon chapalmalensis de la localidad de Mar del Plata, Buenos Aires, Argentina. El material consiste en un gran fragmento de coraza dorsal y en varios trozos de osteodermos asociados, asignables a una especie indeterminada de Panochthus. Uno de los caracteres más significativos es la presencia, a nivel de la superficie expuesta de los osteodermos, de figuritas que siguen un evidente patrón reticular, solo observable en Panochthus. Desde el punto de vista bioestratigráfico, es llamativa la ausencia de registros de Panochthus en la Edad Marplatense (Plioceno tardío-Pleistoceno temprano.

First record of giant anteater (xenarthra, myrmecophagidae) in north america.

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Shaw, C A; McDonald, H G

1987-04-10

A right metacarpal III represents the first North American record of the giant anteater (Myrmecophaga tridactyla). Recovered in northwestern Sonora, Mexico, with a rich vertebrate fauna of early Pleistocene (Irvingtonian) age, it belongs to a cohort of large mammals that dispersed from South America to North America along a savanna corridor. Presumably habitat and climatic changes have subsequently driven this mammalian family more than 3000 kilometers back into Central America from its former expansion into temperate North America.

Youngest radiocarbon age for Jefferson's ground sloth, Megalonyx jeffersonii (Xenarthra, Megalonychidae)

DEFF Research Database (Denmark)

Gregory McDonald, H.; Stafford, Thomas W.; Gnidovec, Dale M.

2015-01-01

A partial skeleton of the extinct ground sloth, Megalonyx jeffersonii, recovered from a farm near Millersburg, Ohio in 1890, was radiocarbon dated for the first time. The ungual dated is part of a skeleton mounted for exhibit at the Orton Geological Museum at Ohio State University and was the fir...

SEROLOGIC RESPONSE TO CANINE DISTEMPER VACCINATION IN CAPTIVE LINNAEUS'S TWO-TOED SLOTHS ( CHOLOEPUS DIDACTYLUS) AFTER A FATAL CANINE DISTEMPER VIRUS OUTBREAK.

Science.gov (United States)

Sheldon, Julie D; Cushing, Andrew C; Wilkes, Rebecca P; Anis, Eman; Dubovi, Edward J

2017-12-01

Canine distemper virus (CDV) affects many wild and captive, nondomestic species worldwide but has not been previously reported in Xenarthra. Paucity of information on vaccination safety and efficacy presents challenges for disease prevention in captive collections. CDV infections and subsequent mortalities in five captive Linnaeus's two-toed sloths ( Choloepus didactylus) in eastern Tennessee are reported. Clinical signs included oculonasal discharge, oral ulcerations, and diarrhea, and the diagnosis was confirmed by necropsy, histopathology, immunohistochemistry, virus isolation, and polymerase chain reaction. Viral sequencing identified the strain to be consistent with a new CDV lineage currently affecting domestic dogs and wildlife in Tennessee. Seven sloths were examined and vaccinated using a recombinant CDV vaccine on days 0 and 21. Subsequent blood samples showed increased titers in 3/4 sloths. Based on the outbreak and serologic findings postvaccination without adverse effects, the authors recommend recombinant CDV vaccination in sloths exposed to known carriers of CDV.

Social behavior between mothers ´ young of sloths Bradypus variegatus SCHINZ, 1825 (Xenarthra: Bradypodidae

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SOARES C. A.

2002-01-01

Full Text Available This study is a contribution to the ex situ and in situ conservation and preservation of Sloths. The behavioral records of the social interaction between mothers and offspring allow the detection of important learning interactions and psychomotor development. The results provide valuable information that may assist in improving management conditions of captive orphan progeny. They also favor a more effective monitoring of released or transferred specimens. Age is of fundamental importance in deciding what is important during the release, transfer, or reintroduction of the species.

Hábito alimentar do tatu-canastra (Xenarthra, Dasypodidae em uma área de cerrado do Brasil Central Food habits of the giant armadillo (Xenarthra, Dasypodidae in an area of grassland of central Brasil

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Teresa Cristina S. Anacleto

2001-09-01

Full Text Available The diel of the giant armadillo - Priodontes maximus (Kerr,1792 - was studied in the field at Fazenda São Miguel, Unaí, Minas Gerais, Brazil, through 82 samples collected at foraging excavations and 25 fecal samples. In both types of sample the most common item was insects (Isoptera e Hymenoptera and, in less quantity, plant fragments and orhers invertebrates (Aranae, Blattaria, Coleoptera, Diplopoda, Scorpiones. These data suggest the giant armadillo is a specialist on insects with an opportunistic foraging strategy.

A brief note on the sleeping habits of the giant anteater - Myrmecophaga tridactyla Linnaeus (Xenarthra, Myrmecophagidae Breve nota sobre hábitos de dormir do tamanduá-bandeira - Myrmecophaga tridactyla Linnaeus (Xenarthra, Myrmecophagidae

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Ísis Meri Medri

2005-12-01

Full Text Available The scientific literature on giant anteaters states that the animal sleeps with its tail folded over its body to conserve body temperature. However, observations of this species in natural habitats indicate variations in this behavior, depending on the ambient temperature.A literatura científica sobre tamanduá-bandeira afirma que o animal dorme com sua cauda dobrada sobre o corpo para conservar a temperatura corporal. Entretanto, observações desta espécie em hábitats naturais indicam variações neste comportamento, dependendo da temperatura ambiente.

The northern naked-tailed armadillo in the Lacandona rainforest, Mexico: new records and potential threats Armadillo de cola desnuda en la selva lacandona, México: nuevos registros y amenazas potenciales

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Arturo González-Zamora

2012-06-01

Full Text Available We review historic occurrences in Mexico of one of the least known Xenarthra of Mesoamerica - the northern naked-tailed armadillo (Cabassous centralis Miller, 1899. We document 6 new records in the Lacandona rainforest, southern Mexico, and through interviews with local people, we assess potential threats for this species in the region. In addition to being locally rare, our results show that hunting and death by road-kill may be major threats to this species in the region.Se revisaron los registros históricos en México de uno de los xenartros menos conocidos de Mesoamérica - el armadillo de cola desnuda (Cabassous centralis Miller, 1899. Se documentan 6 nuevos registros en la selva lacandona, sur de México. A través de entrevistas con pobladores locales, se evaluaron las amenazas potenciales para esta especie en la región. Además de ser localmente rara, nuestros resultados muestran que la cacería y las muertes por atropellamiento pueden ser las principales amenazas para esta especie en la región.

Origin and distribution of the axillary nerve in the giant anteater (Myrmecophaga tridactyla

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Daniela Cristina de Oliveira Silva

2012-09-01

Full Text Available The giant anteater (Myrmecophaga tridactyla, a mammal belonging to the order Xenarthra and family Myrmecophagidae, is an endangered species. For this reason, additional knowledge about its anatomy is of interest, especially the forelimb, which plays important roles in feeding and defense. The goal of this study was to learn more about the origin and distribution of the axillary nerve of Myrmecophaga tridactyla by studying two individuals (one male and one female that belong to the Research Laboratory of Wild Animals (UFU. The study material consisted of corpses fixed and preserved in 10% aqueous formalin solution. Dissection of the material followed standard procedures. In both animals, the axillary nerve was found in the ventral branch of the sixth cervical (C6 and seventh (C7 spinal nerve. This nerve showed symmetry in relation to its position in the two specimens and branched into the teres major, teres minor and deltoid muscles. In both specimens the axillary nerve originated in the cranial cutaneous branch of the lower leg.

Reproductive System of Brown-throated Sloth (Bradypus variegatus, Schinz 1825, Pilosa, Xenarthra): Anatomy and Histology.

Science.gov (United States)

Favoretto, S M; daSilva, E G; Menezes, J; Guerra, R R; Campos, D B

2016-08-01

In recent years, habitat degradation led to the decline of some populations of brown-throated sloth. The aim of this study was to describe morphological features of the female reproductive system of the species. The oval ovaries were partially surrounded by ovarian bursa. An external cortex and an inner medulla were present. Corpora lutea and corpora albicans together with follicles at various stages of development each with a single oocyte were found in the cortex. Uterine tubes were tortuous, tubular, travelled around the perimeter of the ovary and possessed a folded mucosa with ciliated pseudostratified epithelium. Uterus was simplex, with no horns and divided into three parts: a pear-shaped cranial segment and a long caudal uterine segment (both forming the body of the uterus) and two cervices. Uterus presented three layers: mucosa, lined by pseudostratified epithelium, muscular and serosa. The cervices connected the uterus to the urogenital sinus, a distensible cavity with longitudinal mucosal folds lined by transitional epithelium that extended from the external urethral orifice and the external uterine ostia to the vulva, which was lined by a keratinized stratified squamous epithelium. Brown-throated sloth presented a bipartite clitoris with paired crura, bodies and glandes. The presence of a double cervix and a bipartite clitoris was unique features of the species. © 2015 Blackwell Verlag GmbH.

Terrestrial mammals in an Atlantic Forest remnant, Paraná, Brazil

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Gustavo Borba de Miranda

2013-11-01

Full Text Available The threat degree and the ecological importance of terrestrial mammals make clear the need for constantly conducting researches in order to add information to the current knowledge on this theme. This study aimed to provide a list of terrestrial mammal species in an Atlantic Forest remnant located in the Southwestern Paraná state, Brazil. Species richness and occurrence frequency were studied from April to October 2009 using two methods: direct observation and recording of traces. We registered 20 taxa distributed into 7 orders: Artiodactyla, Carnivora, Didelphimorphia, Lagomorpha, Primates, Rodentia, and Xenarthra. Among these, 4 taxa were registered either by direct observation or by recording of traces and the others were registered only through traces. The most frequently occurring species were Didelphis sp. (30.6% and Cerdocyon thous (25.6%. Out of the 20 registered taxa, Leopardus pardalis, Leopardus tigrinus, and Cuniculus paca are listed as vulnerable in the Red Book of Threatened Fauna in Parana State. Although small, the study area may assist in the availability of food and shelter for the fauna of mammals, representing an important element of the regional landscape.

Renal morphology of Bradypus torquatus

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Pedro Kastein Faria da Cunha Bianchi

2012-11-01

Full Text Available Among the Xenarthras, sloths present a hydric ingestion restricted to water from leaves, fruits, and vegetables. As a first approach to verify whether these animals have some morphophysiological difference which could justify or compensate this low hydric ingestion, the renal anatomy of these animals was investigated, particularly that of maned sloth (Bradypus torquatus. Kidneys from these animals were macroscopically analyzed, through light microscopy and scanning electron microscopy. The Bradypus torquatus kidneys are bean-shaped paired organs, located dorso-cranially to the pelvic girdle, between the peritoneum and the posterior abdominal wall. The use of histological techniques allowed us to identify, in the cortical region, the renal corpuscles and tubules, and, in the medullary region, a significant amount of interstitial tissue with a collecting duct. The results of this study showed that, although Bradypus torquatus doesn’t drink water directly, its kidneys doesn’t differ from that of most mammals, presenting the same anatomical structure, suggesting that these animals fully reach their hydric needs, basically by consuming leaves, fruits, and sprouts. Nevertheless, in order to confirm this hypothesis, studies on the effectiveness of water reabsorption, such as the renin-angiotensin-aldosterone system, must be carried out.

Late Pleistocene ecological, environmental and climatic reconstruction based on megafauna stable isotopes from northwestern Chilean Patagonia

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González-Guarda, Erwin; Domingo, Laura; Tornero, Carlos; Pino, Mario; Hernández Fernández, Manuel; Sevilla, Paloma; Villavicencio, Natalia; Agustí, Jordi

2017-08-01

Stable isotope analyses have been performed on the bioapatite (δ13C; δ18O) and collagen (δ13C; δ15N) of four late Pleistocene South American megafaunal taxa (Notiomastodon platensis, Equus andium, cf. Hemiauchenia paradoxa and Xenarthra indet.) to evaluate paleoclimatic and paleoenvironmental conditions as well as paleoecological features of this time period. The analyzed megafauna was found at several locations in the northwestern Chilean Patagonia (38°-42°S, 74°-71°W). The bioapatite δ13C values indicated the presence of C3 vegetation ranging from forestal to woodland areas. The collagen δ15N values pointed to temperate and humid ecosystems, and to the consumption of shrubs, trees, grasses and sedges. Mean annual temperatures estimated from bioapatite δ18OPO4 values show a similarity to modern temperatures and suggested that the megafauna under study may have lived during warm stages (interstadials) of the late Pleistocene. When comparing our results with those obtained from other South American regions, we find that the diet of this particular Chilean megafauna appears to have been more influenced by resource availability than by the potential dietary range of the taxa.

Anatomia do circuito arterial do encéfalo em Tamanduá-mirim Anatomy of encephalon arterial circuit in lesser anteater

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Ana Rita Lima

2013-02-01

Full Text Available O circuito arterial do encéfalo é de grande importância, pois é responsável pela vascularização do encéfalo, sendo este o principal órgão do sistema nervoso central e responsável por receber e processar informações. A espécie estudada foi escolhida por tratar-se de um mamífero pertencente à ordem Xenarthra e os integrantes dessa ordem são pouco estudados, devido à dificuldade de acesso a esses animais. Para desenvolver este trabalho, foram estudados cinco espécimes de Tamanduá-mirim (Tamandua tetradactyla. O material teve o sistema arterial injetado com látex Neoprene 650, corado em vermelho e fixado em solução aquosa de Formaldeído 10%, sendo posteriormente dissecados para sistematização dos vasos. O circuito arterial da base do encéfalo do tamanduá-mirim circunda o corpo mamilar, a fossa interpenduncular, o túber cinéreo, a hipófise e o quiasma óptico. A porção rostral desse circuito é caracterizada pelos ramos rostrais das artérias carótidas internas e a porção caudal é constituída pelas artérias comunicantes caudais e ramos caudais da artéria carótida interna. Esta espécie animal apresenta o tipo II de irrigação encefálica no qual existe a participação das artérias carótidas internas e do sistema vértebro-basilar para a formação do circuito arterial.The arterial circuit of the brain is of great importance because it is responsible for vascularization of the brain and this is the main organ of the central nervous system and responsible for receiving and processing information. The species was chosen because it is a mammal belonging to the Xenarthra order and the members of this order are little studied because of the difficulty of access to these animals. To develop this work were studied five specimens of lesser anteater (Tamandua tetradactyla. The material had the arterial system filled with Neoprene latex stained in red, fixed in aqueous solution of 10% paraformaldehyde and dissected

Breve nota sobre hábitos de dormir do tamanduá-bandeira - Myrmecophaga tridactyla Linnaeus (Xenarthra, Myrmecophagidae)

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Medri, Ísis Meri; Mourão, Guilherme

2005-01-01

The scientific literature on giant anteaters states that the animal sleeps with its tail folded over its body to conserve body temperature. However, observations of this species in natural habitats indicate variations in this behavior, depending on the ambient temperature.A literatura científica sobre tamanduá-bandeira afirma que o animal dorme com sua cauda dobrada sobre o corpo para conservar a temperatura corporal. Entretanto, observações desta espécie em hábitats naturais indicam variaçõe...

First record of Nopachtus coagmentatus (Xenarthra, Glyptodontidae for the Catamarca Province, Argentina. Revision of the genus Nopachtus

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M. Zamorano

2017-09-01

Full Text Available Nopachtus coagmentatus was recognized by Ameghino in 1888. Holotype comes from Brochero Formation (Montehermosan - Chapadmalalan [early Pliocene - late Pliocene], near to Villa Cura Brochero (Córdoba. First find of this species for the Catamarca Province is reported. Remains found are described, its provenance detailed and the corresponding stratigraphic log is presented. The mentioned material, came from Salicas Formation, cropping out in the paraje Suri Yaco, consists of 14 osteoderms of the dorsal region of the carapace attributed to N. coagmentatus, 12 complete and 2 fragmented corresponding to the media and posterodorsal region of the carapace. These osteoderms present a central figure surrounded by two row of peripheral figures, and figures that would correspond to a third row, always incomplete. The first row has between 10 and 12 figures and the second between 19 and 22; the figures are pentagonal or, mainly, hexagonal. In turn, all specimens known today for this genus, that included two species, is revised. Until this communication, only two reliable records, and several doubtful were recognized for N. coagmentatus; while for N. cabrerai Zamorano, Scillato-Yané, Gonzalez Ruiz & Zurita only the holotype was given to known.

Morphological description of collateral branches from the abdominal aorta of lesser anteater (Tamandua tetradactyla

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Breno Costa Macedo

2013-03-01

Full Text Available Tamandua tetradactyla, Xenarthra, is a native species from South America which, due to the few number of studies on its biology, still has many unknown aspects in its morphology. Taking into account the importance of morphological data for various studies, this paper aimed to elucidate the branching of the abdominal aorta in this species to foster the development of further studies. To do this, 4 specimens were used, 2 male and 2 female, all young, from the Bauxite Mine – Paragominas, Para, Brazil, donated after death due to running over to the Animal Morphology Research Laboratory (LaPMA of Universidade Federal Rural da Amazonia (UFRA. The arterial system was filled with contrasted latex and the animals were fixed in a formaldehyde solution (10%, and then dissected, in order to evidence the abdominal aorta and its collateral branches. The parietal branches consisted of 1 pair of caudal phrenic arteries, 2 pairs of intercostal arteries, and 3 pairs of lumbar arteries. Among the visceral branches, stood out: celiac artery; cranial mesenteric artery; adrenal arteries; renal arteries; caudal mesenteric artery; and external, internal, and median sacral iliac arteries, formed from the final portion of the abdominal aorta. Testicular and ovarian arteries originated from the renal arteries, differing from that described in various species.

El registro más completo de un Hoplophorini (Xenarthra: Glyptodontidae para los Pisos/Edades Chapadmalalense-Marplatense (Plioceno tardío-Pleistoceno temprano The most complete record of a Hoplophorini (Xenarthra: Glyptodontidae for the Chapadmalalan-Marplatan Stages (Late Pliocene-Early Pleistocene

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Alfredo E Zurita

2011-06-01

Full Text Available Los Glyptodontidae del Neógeno tardío (Pisos/Edades Chapadmalalense-Marplatense; ca. 3.9-1.8 Ma constituyen un grupo escasamente conocido, en tanto la mayoría de los registros están limitados a restos aislados de la coraza dorsal y/o caudal. Las únicas excepciones están representadas por Paraglyptodon chapalmalensis (Ameghino in Rovereto, un fósil guía para el Chapadmalalense superior, y el Plohophorini Plohophorus figuratus Ameghino. Por otro lado, los "Hoplophorinae" Hoplophorini son gliptodontes que tienen sus primeros registros durante los Pisos Huayqueriense (Mioceno tardío y "Araucanense" (Mioceno tardío-Plioceno, pero están prácticamente ausentes durante los Pisos Chapadmalalense-Marplatense (Plioceno-Pleistoceno temprano. Posteriormente, los Hoplophorini (Neosclerocalyptus Paula Couto son, junto con Glyptodon Owen, los Glyptodontidae de registro más frecuente en el Pleistoceno de América del Sur. En esta contribución damos a conocer el primer registro de un Hoplophorini de antigüedad Chapadmalalense, asignado al género Eosclerocalyptus C. Ameghino (Eosclerocalyptus cf. E. lineatus. Este nuevo material, representado por una coraza dorsal, fue exhumado de la sección superior de la Fm. Chapadmalal, Mar del Plata, provincia de Buenos Aires. Desde una perspectiva morfológica, esta coraza presenta un tamaño intermedio entre E. tapinocephalus Cabrera, E. proximus (Moreno & Mercerat y Neosclerocalyptus Paula Couto. Junto con cf. Paraglyptodon chapalmalensis y Plohophorus figuratus Ameghino, estos registros representan los Glyptodontidae Pliocenos más completos que se conocen; a su vez, completa parcialmente la distribución estratigráfica de los Glyptodontidae Hoplophorini.The late Neogene (Chapadmalalan-Marplatan Stages; ca. 3.9-1.8 Ma Glyptodontidae from southern South America are poorly known since most of the record are limited to remains of the dorsal and/or caudal armour. In this sense, the exceptions are represented by Paraglyptodon chapadmalensis (Ameghino in Rovereto, a fossil guide of the Upper Chapadmalalan Stage, and the Plohophorini Plohophorus figuratus Ameghino. On the other hand, the "Hoplophorinae" Hoplophorini are glyptodonts that have its first records during the Huayquerian (late Miocene and "Araucanian" Stages (late Miocene-early Pliocene, but they are almost absents during the Chapadmalalan-Marplatan Stages (Pliocene-early Pleistocene. Later, the Hoplophorini (Neosclerocalyptus Paula Couto are, together with Glyptodon Owen, the most common South American Pleistocene Glyptodontidae. In this contribution we report the first record of a Chapadmalalan Hoplophorini, assigned to the genus Eosclerocalyptus C. Ameghino (Eosclerocalyptus cf. E. lineatus, coming from the Mar del Plata locality, Buenos Aires province (Argentina. This new material, represented by a complete dorsal carapace, was exhumed from the upper section of the Chapadmalalan Formation. From a morphological perspective, this dorsal carapace shows an intermediate size between E. tapinocephalus Cabrera, E. proximus (Moreno & Mercerat and Neosclerocalyptus Paula Couto. Together with cf. Paraglyptodon chapadmalensis and Plohophorus figuratus Ameghino those records represents the most entire Pliocene Glyptodontidae known and, in addition, it partially complete the stratigraphical distribution of the Glyptodontidae Hoplophorini.

Estudio geológico, estratigráfico y sedimentológico de la Cueva de Mamíferos del Pleistoceno de Santa Rosa (Perú: interpretación paleo-ambiental

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2002-01-01

Full Text Available ÉTUDE GÉOLOGIQUE, STRATIGRAPHIQUE ET SÉDIMENTOLOGIQUE DE LA GROTTE À MAMMIFÈRES PLÉISTOCÈNES DE SANTA ROSA (PÉROU : INTERPRÉTATION PALÉO-ENVIRONNEMENTALE. Les restes d’un spécimen de Megatheriinae (Mammalia: Xenarthra pléistocène (Lujanien viennent d’être mis à jour dans la grotte de Santa Rosa, située dans les Andes Nord-péruviennes. Cette découverte d’un squelette sub-complet de Gravigrade, fait exceptionnel dans les Andes, correspond à une nouvelle espèce du genre Megatherium. L’étude sédimentologique, pétrographique, stratigraphique et palynologique de la grotte montre que la cavité : - appartient à un système karstique (habituel dans cette région des Andes péruviennes creusée dans le calcaire de la formation Celendín (Coniacien - Santonien inférieur - a été soumise à des événements successifs : 1 le creusement de l’abri et le dépôt des sables calcaréo-argileux jaunes suite à la forte érosion du massif calcaire 2 le ravinement et l’érosion amenant des effondrements du toit de l’abri 3 le dépôt des sables calcaréo-argileux marrons où se trouvent les restes de mammifères (Megatheriidae, Camelidae, Cervidae et Muridae et de nombreux restes de flore et la présence locale de pollens. L’analyse pollinique semble indiquer l’existence d’une flore dominée par les fougères d’origine locale et parfois de spores coloniales indifférenciées d’origine vraisemblablement algaire. Ces observations suggèrent que les conditions climatiques étaient plus froides et humides que de nos jours. Restos de un espécimen de Megatheriinae (mammalia: Xenarthra del Pleistoceno superior [Lujanense] han sido descubiertos en la cueva de Santa Rosa, en el norte de los Andes del Perú. Este hallazgo de un esqueleto parcialmente completo de Gravigrado, hecho excepcional en los Andes, corresponde a una nueva especie del género Megatherium. El estudio sedimentológico, petrográfico, estratigráfico y palinol

ON THE PRESENCE OF PYRAMIODONTHERIUM (MAMMALIA, XENARTHRA, MEGATHERIIDAE IN THE LATE MIOCENE OF NORTHEASTERN ARGENTINA AND ITS BIOGEOGRAPHICAL IMPLICATIONS

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DIEGO BRANDONI

2009-03-01

Full Text Available The biochron of the subfamily Megatheriinae, large to very large terrestrial sloths typified by Megatherium Cuvier, in Argentina extends from the middle Miocene of Patagonia to the late Pleistocene-early Holocene. Megatheriines reached their highest diversity in the lower levels (="conglomerado osífero", late Miocene of the Ituzaingó Formation in Entre Ríos Province, northeastern Argentina. Among the four megatheriines that occur in this unit, the genera Promegatherium Ameghino, Eomegatherium Kraglievich and Pliomegatherium Kraglievich represent relatively small to medium-sized taxa. Here we describe new material assigned to Pyramiodontherium, the largest of the four genera from the same bed and comparable in size to some Quaternary species of Megatherium. Three valid species of Pyramiodontherium have been recognized, all distributed mainly in northwestern Argentina, from the late Miocene in Catamarca Province (and probably also in Tucumán Province, and the late Pliocene in La Rioja Province. The presence of this genus in northeastern Argentina extends its known paleobiogeographical distribution. 

Primer registro fehaciente de Nopachtus coagmentatus (Xenarthra, Cingulata, Glyptodontidae en la región Pampeana, Argentina. Contexto estratigráfico

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Zamorano, M.

2015-06-01

Full Text Available The species Nopachtus coagmentatus was recognized by Amegino in 1888, on the basis of sections of the caudal tube and the dorsal carapace. These remains comes from Valles de las Sierras de Córdoba near Villa Cura Brochero, and stratigraphically from the Brochero Formation (Montehermosan-Chapadmalalan [early Pliocene - late Pliocene]. Ameghino also mentioned N. coagmentatus for the Monte Hermoso Formation (Montehermosan, but the determination Ameghino is highly questionable. The exploitation of Precambrian rocks from the center of the Sierras Bayas in Olavarría (Buenos Aires province allowed the identification from the bottom to the top, of La Alcancía Formation (Miocene, El Polvorín Formation (Pliocene, La Esperanza Formation and El Búho Formation (both late Pleistocene. In this contribution present osteoderms of the latero-dorsal portion of the posterior region of the dorsal carapace of N. coagmentatus. The specimen was extracted from brownish sandy-silt sediments of La Alcancía Quarry (36°58′40′′.06 S; 60°12′23′′.92 W corresponding to El Polvorín Formation (Upper Chapadmalalan and correspond to the first reliable record of N. coagmentatus for the Pampean region. Finally, we offer a detailed description of the specimen, and its geographic and stratigraphic provenance.La especie Nopachtus coagmentatus fue reconocida por Ameghino en 1888, basándose en porciones del tubo caudal y la coraza dorsal; estos restos proceden de los Valles de las Sierras de Córdoba, en las cercanías de Villa Cura Brochero; y, estratigráficamente, de la Formación Brochero (Montehermosense - Chapadmalalense [Plioceno temprano - Plioceno tardío]. Ameghino también la menciona para la Formación Monte Hermoso (Montehermosense, pero la determinación es altamente dudosa. La explotación de rocas precámbricas en el núcleo central de las Sierras Bayas de Olavarría (provincia Buenos Aires posibilitó el reconocimiento de la Formación El Polvorín (Plioceno y, suprayacentes a esta, otras dos: Formación Esperanza y Formación El Búho (Pleistoceno tardío. El material que se da a conocer en esta comunicación fue exhumado en la Cantera Alcancía (36°58′40′′.06 S; 60°12′23′′.92 O, en niveles correspondientes al Chapadmalalense Superior de la Formación El Polvorín. El material mencionado consiste en osteodermos de la región dorso-lateral de la porción posterior de la coraza dorsal de N. coagmentatus. Se da a conocer el primer registro fehaciente de N. coagmentatus para la región Pampeana, se describe el material hallado, se detalla su procedencia y se presenta el perfil estratigráfico detallado correspondiente.

A higher-level MRP supertree of placental mammals

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Bininda-Emonds Olaf RP

2006-11-01

Full Text Available Abstract Background The higher-level phylogeny of placental mammals has long been a phylogenetic Gordian knot, with disagreement about both the precise contents of, and relationships between, the extant orders. A recent MRP supertree that favoured 'outdated' hypotheses (notably, monophyly of both Artiodactyla and Lipotyphla has been heavily criticised for including low-quality and redundant data. We apply a stringent data selection protocol designed to minimise these problems to a much-expanded data set of morphological, molecular and combined source trees, to produce a supertree that includes every family of extant placental mammals. Results The supertree is well-resolved and supports both polyphyly of Lipotyphla and paraphyly of Artiodactyla with respect to Cetacea. The existence of four 'superorders' – Afrotheria, Xenarthra, Laurasiatheria and Euarchontoglires – is also supported. The topology is highly congruent with recent (molecular phylogenetic analyses of placental mammals, but is considerably more comprehensive, being the first phylogeny to include all 113 extant families without making a priori assumptions of suprafamilial monophyly. Subsidiary analyses reveal that the data selection protocol played a key role in the major changes relative to a previously published higher-level supertree of placentals. Conclusion The supertree should provide a useful framework for hypothesis testing in phylogenetic comparative biology, and supports the idea that biogeography has played a crucial role in the evolution of placental mammals. Our results demonstrate the importance of minimising poor and redundant data when constructing supertrees.

Origem e distribuição do nervo axilar em tamanduá-bandeira (Myrmecophaga tridactyla

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Luciana Aparecida Rosa

2012-06-01

Full Text Available http://dx.doi.org/10.5007/2175-7925.2012v25n3p249   O tamanduá-bandeira (Myrmecophaga tridactyla, mamífero pertencente à ordem Xenarthra, família Myrmecophagidae, está entre as espécies ameaçadas de extinção. Partindo desse pressuposto, o conhecimento da sua anatomia é de extrema insigne, principalmente do membro torácico que desempenha funções importantes na sua alimentação e como único meio de defesa. Assim, objetivou-se estudar a origem e distribuição do nervo axilar em dois tamanduás-bandeira (Myrmecophaga tridactyla, um macho e uma fêmea, pertencentes ao Laboratório de Ensino e Pesquisa de Animais Silvestres (LAPAS. Esse material consta de cadáveres fixados e conservados em solução aquosa de formol a 10% e a dissecação seguiu os procedimentos usuais em anatomia. O nervo axilar originou-se em 100% dos animais dos ramos ventrais do sexto (C6 e sétimo (C7 nervos espinhais cervicais. O referido nervo apresentou simetria em relação a sua origem e emitiu ramos para os músculos redondo maior, redondo menor e deltóide em 100% dos espécimes. Em todos os animais o nervo axilar emitiu o ramo cutâneo cranial do antebraço.

A novel abundant family of retroposed elements (DAS-SINEs) in the nine-banded armadillo (Dasypus novemcinctus).

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Churakov, Gennady; Smit, Arian F A; Brosius, Jürgen; Schmitz, Jürgen

2005-04-01

About half of the mammalian genome is composed of retroposons. Long interspersed elements (LINEs) and short interspersed elements (SINEs) are the most abundant repetitive elements and account for about 21% and 13% of the human genome, respectively. SINEs have been detected in all major mammalian lineages, except for the South American order Xenarthra, also termed Edentata (armadillos, anteaters, and sloths). Investigating this order, we discovered a novel high-copy-number family of tRNA derived SINEs in the nine-banded armadillo Dasypus novemcinctus, a species that successfully crossed the Central American land bridge to North America in the Pliocene. A specific computer algorithm was developed, and we detected and extracted 687 specific SINEs from databases. Termed DAS-SINEs, we further divided them into six distinct subfamilies. We extracted tRNA(Ala)-derived monomers, two types of dimers, and three subfamilies of chimeric fusion products of a tRNA(Ala) domain and an approximately 180-nt sequence of thus far unidentified origin. Comparisons of secondary structures of the DAS-SINEs' tRNA domains suggest selective pressure to maintain a tRNA-like D-arm structure in the respective founder RNAs, as shown by compensatory mutations. By analysis of subfamily-specific genetic variability, comparison of the proportion of direct repeats, and analysis of self-integrations as well as key events of dimerization and deletions or insertions, we were able to delineate the evolutionary history of the DAS-SINE subfamilies.

Mamíferos terrestres em um remanescente de Mata Atlântica, Paraná, Brasil

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Márcia Regina Wolfart

2013-10-01

Full Text Available http://dx.doi.org/10.5007/2175-7925.2013v26n4p111 O grau de ameaça e a importância ecológica dos mamíferos terrestres evidenciam a necessidade da constante realização de pesquisas com o intuito de acrescentar informações ao conhecimento atual sobre esse tema. Este estudo teve por objetivo fornecer uma lista de espécies de mamíferos terrestres em um remanescente de Mata Atlântica localizado no sudoeste do estado do Paraná. A riqueza de espécies e a frequência de ocorrência foram estudadas de abril a outubro de 2009, utilizando dois métodos: observação direta e registro de vestígios. Foram registrados 20 táxons distribuídos em sete ordens: Artiodactyla, Carnivora, Didelphimorphia, Lagomorpha, Primates, Rodentia e Xenarthra. Dentre estes, quatro táxons foram registrados tanto por observação direta quanto pelo registro de vestígios e os demais foram registrados somente por meio de vestígios. As espécies com ocorrência mais frequente foram Didelphis sp. (30,6% e Cerdocyon thous (25,6%. Dos 20 táxons registrados, Leopardus pardalis, Leopardus tigrinus e Cuniculus paca constam como vulneráveis no Livro Vermelho da Fauna Ameaçada no Estado do Paraná. Apesar de pequena, a área de estudo deve auxiliar na disponibilidade de alimento e abrigo para a mastofauna, representando um importante elemento da paisagem regional.

Importance of xenarthrans in the eco-epidemiology of Paracoccidioides brasiliensis

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Pedrini Silvia CB

2009-11-01

Full Text Available Abstract Background Several pathogens that cause important zoonotic diseases have been frequently associated with armadillos and other xenarthrans. This mammal group typically has evolved on the South American continent and many of its extant species are seriously threatened with extinction. Natural infection of armadillos with Paracoccidioides brasiliensis in hyperendemic areas has provided a valuable opportunity for understanding the role of this mammal in the eco-epidemiology of Paracoccidioidomycosis (PCM, one of the most important systemic mycoses in Latin America. Findings This study aimed to detect P. brasiliensis in different xenarthran species (Dasypus novemcinctus, Cabassous spp., Euphractus sexcinctus, Tamandua tetradactyla and Myrmecophaga tridactyla, by molecular and mycological approaches, in samples obtained by one of the following strategies: i from road-killed animals (n = 6; ii from naturally dead animals (n = 8; iii from animals that died in captivity (n = 9; and iv from living animals captured from the wild (n = 2. Specific P. brasiliensis DNA was detected in several organs among 7/20 nine-banded armadillos (D. novemcinctus and in 2/2 anteaters (M. tridactyla. The fungus was also cultured in tissue samples from one of two armadillos captured from the wild. Conclusion Members of the Xenarthra Order, especially armadillos, have some characteristics, including a weak cellular immune response and low body temperature, which make them suitable models for studying host-pathogen interaction. P. brasiliensis infection in wild animals, from PCM endemic areas, may be more common than initially postulated and reinforces the use of these animals as sentinels for the pathogen in the environment.

Importance of xenarthrans in the eco-epidemiology of Paracoccidioides brasiliensis.

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Richini-Pereira, Virgínia B; Bosco, Sandra M G; Theodoro, Raquel C; Barrozo, Lígia; Pedrini, Silvia C B; Rosa, Patrícia S; Bagagli, Eduardo

2009-11-17

Several pathogens that cause important zoonotic diseases have been frequently associated with armadillos and other xenarthrans. This mammal group typically has evolved on the South American continent and many of its extant species are seriously threatened with extinction. Natural infection of armadillos with Paracoccidioides brasiliensis in hyperendemic areas has provided a valuable opportunity for understanding the role of this mammal in the eco-epidemiology of Paracoccidioidomycosis (PCM), one of the most important systemic mycoses in Latin America. This study aimed to detect P. brasiliensis in different xenarthran species (Dasypus novemcinctus, Cabassous spp., Euphractus sexcinctus, Tamandua tetradactyla and Myrmecophaga tridactyla), by molecular and mycological approaches, in samples obtained by one of the following strategies: i) from road-killed animals (n = 6); ii) from naturally dead animals (n = 8); iii) from animals that died in captivity (n = 9); and iv) from living animals captured from the wild (n = 2). Specific P. brasiliensis DNA was detected in several organs among 7/20 nine-banded armadillos (D. novemcinctus) and in 2/2 anteaters (M. tridactyla). The fungus was also cultured in tissue samples from one of two armadillos captured from the wild. Members of the Xenarthra Order, especially armadillos, have some characteristics, including a weak cellular immune response and low body temperature, which make them suitable models for studying host-pathogen interaction. P. brasiliensis infection in wild animals, from PCM endemic areas, may be more common than initially postulated and reinforces the use of these animals as sentinels for the pathogen in the environment.

Trichostrongylina parasites of Dasypodidae (Xenarthra) from Argentina; a new species of Macielia (Molineidae: Anoplostrongylinae) in Chaetophractus vellerosus and redescription of Trichohelix tuberculata.

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Ezquiaga, María C; Navone, Graciela T

2013-10-01

Macielia jorgei n. sp. is described from Chaetophractus vellerosus from La Rioja, Argentina. Also Trichohelix tuberculata is redescribed in detail. The new species is characterized by parasitizing the small intestine, possessing a bursal membrane and telamon, having complex and sclerotized spicules distally divided into 2 processes, a simple, poorly sclerotized gubernaculum, and synlophe with bilateral symmetry and 12 cuticular ridges. This is the second report of a species of Macielia in Argentina. The synlophe of Trichohelix tuberculata is asymmetric and is characterized by 3 ventral ridges, oriented to the left. The size of these ridges decreases until they disappear at midbody.

Ontogenetic criteria to distinguish vertebral types on the debated xenarthran synsacrum.

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Galliari, Fernando C; Carlini, Alfredo A

2015-05-01

The presence of a synsacrum formed by the fusion of vertebrae that come into closed contact with the ilium and ischium is a feature that characterizes the clade Xenarthra. Nevertheless, the proper identity of each vertebral element that forms it is a matter of discussion. In this article, we provide ontogenetic information about skeletal ossification of the xenarthran synsacrum and define the position of the sacrocaudal limit within it. We analyzed the synsacrum of 25 specimens of nonadult and 101 adult armadillos and anteaters: Dasypus hybridus, D. novemcinctus, Chaetophractus vellerosus, C. villosus, Tamandua tetradactyla, and Myrmecophaga tridactyla. Two sets of vertebrae were identified: an anterior set, often attached to the iliac bones, in which transverse processes are originated mainly from an expansion of the base of the neural arches, and secondarily from a lateroventral ossification center. A posterior set is characterized by a series of vertebrae along which extra lateral ossifications (described here for the first time) are developed and form exclusively the transverse processes. Among armadillos, the sacrocaudal limit is set between the last vertebrae attached to the iliac bones and the first vertebrae that form the dorsal border of the sacroischial fenestra. In addition, anterior free caudals also showed extra lateral ossifications forming exclusively the transverse processes, supporting the notion that more posterior synsacrals are in fact caudal vertebrae that were incorporated to the synsacrum. In pilosans, the sacrocaudal limit is set between the first vertebrae that come into contact with the ischial bones and the immediately anterior one. However, the pattern of homologies is obscured by the low resolution in the ontogenetic sequence when compared to that of armadillos. © 2014 Wiley Periodicals, Inc.

Morfologia renal do Bradypus torquatus

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Pedro Faria da Cunha Bianchi Kastein

2012-08-01

Full Text Available http://dx.doi.org/10.5007/2175-7925.2012v25n4p201   Dentre os Xenarthras, as preguiças apresentam uma ingestão hídrica restrita à água das folhas, frutas e legumes. Como primeira abordagem para verificar se esses animais possuem alguma diferença morfofisiológica que possa justificar ou compensar essa baixa ingestão hídrica, investigou-se a anatomia renal desses animais, particularmente a da preguiça-de-coleira (Bradypus torquatus. Os rins desses animais foram analisados macroscopicamente, pela microscopia de luz e pela microscopia eletrônica de varredura. Os rins do Bradypus torquatus são órgãos pares em forma de grão de feijão, localizados dorso-cranialmente à cintura pélvica, entre o peritônio e a parede posterior do abdome. A utilização das técnicas histológicas possibilitou identificar, na região cortical, os corpúsculos e túbulos renais e, na região medular, uma quantidade significativa de tecido intersticial com um ducto coletor. Os resultados deste estudo mostraram que apesar do Bradypus torquatus não ingerir água diretamente, seu rim não difere da maioria dos mamíferos, apresentando as mesmas estruturas anatômicas, sugerindo que esses animais alcançam plenamente suas necessidades hídricas pelo consumo de folhas, frutas e brotos. Contudo, a fim de confirmar essa hipótese, estudos sobre a eficiência da reabsorção hídrica, como o sistema renina-angiotensina-aldosterona, necessitam ser realizados.

Nuevos aportes a la historia natural de la mulita pampeana Dasypus hybridus (Mammalia, Dasypodidae

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Agustín M. Abba

2011-12-01

Full Text Available En este trabajo se presentan nuevos aportes sobre la historia natural de la mulita pampeana Dasypus hybridus (Desmarest, 1804 (Mammalia, Xenarthra, Dasypodidae. Los estudios de campo fueron llevados a cabo en 100 ha de cuatro establecimientos agropecuarios de la provincia de Buenos Aires, Argentina. Durante tres años se realizó un muestreo estacional de armadillos por captura y liberación. Se obtuvieron datos de hábitos alimentarios, uso del espacio y del tiempo, comportamiento, termorregulación, datos poblacionales y morfológicos. Se realizaron 71 capturas. En la dieta el ítem principal registrado fue material vegetal, seguido por hormigas e insectos coleópteros; no se observó una diferencia estacional en los hábitos alimentarios. La actividad de las mulitas se concentra durante el día, existió una baja en la frecuencia de observación durante las estaciones frías (otoño e invierno. La mulita pampeana prefiere suelos húmicos, terrenos altos y pastizales densos y altos; asimismo seleccionan los montes para refugiarse. Son individuos asociales. La temperatura rectal mostró correlaciones positivas con la temperatura ambiente. La proporción de sexos fue cercana a uno y no se observó dimorfismo sexual. Los resultados obtenidos concuerdan parcialmente con lo observado para otras especies del género, destacando las tendencias observadas en los hábitos alimentarios y en la estrategia termorregulatoria. Este trabajo representa un aporte en varios aspectos de una especie poco estudiada en una zona bajo importantes presiones de uso y modificación de hábitat.

Evolutionary patterns of bone histology and bone compactness in xenarthran mammal long bones.

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Straehl, Fiona R; Scheyer, Torsten M; Forasiepi, Analía M; MacPhee, Ross D; Sánchez-Villagra, Marcelo R

2013-01-01

Bone microstructure reflects physiological characteristics and has been shown to contain phylogenetic and ecological signals. Although mammalian long bone histology is receiving increasing attention, systematic examination of the main clades has not yet been performed. Here we describe the long bone microstructure of Xenarthra based on thin sections representing twenty-two species. Additionally, patterns in bone compactness of humeri and femora are investigated. The primary bone tissue of xenarthran long bones is composed of a mixture of woven, parallel-fibered and lamellar bone. The vascular canals have a longitudinal, reticular or radial orientation and are mostly arranged in an irregular manner. Concentric rows of vascular canals and laminar organization of the tissue are only found in anteater bones. The long bones of adult specimens are marked by dense Haversian bone, a feature that has been noted for most groups of mammals. In the long bones of armadillos, secondary osteons have an oblique orientation within the three-dimensional bone tissue, thus resulting in their irregular shape when the bones are sectioned transversely. Secondary remodeling is generally more extensive in large taxa than in small taxa, and this could be caused by increased loading. Lines of arrested growth are assumed to be present in all specimens, but they are restricted to the outermost layer in bones of armadillos and are often masked by secondary remodeling in large taxa. Parameters of bone compactness show a pattern in the femur that separates Cingulata and Pilosa (Folivora and Vermilingua), with cingulates having a lower compactness than pilosans. In addition, cingulates show an allometric relationship between humeral and femoral bone compactness.

Evolutionary patterns of bone histology and bone compactness in xenarthran mammal long bones.

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Fiona R Straehl

Full Text Available Bone microstructure reflects physiological characteristics and has been shown to contain phylogenetic and ecological signals. Although mammalian long bone histology is receiving increasing attention, systematic examination of the main clades has not yet been performed. Here we describe the long bone microstructure of Xenarthra based on thin sections representing twenty-two species. Additionally, patterns in bone compactness of humeri and femora are investigated. The primary bone tissue of xenarthran long bones is composed of a mixture of woven, parallel-fibered and lamellar bone. The vascular canals have a longitudinal, reticular or radial orientation and are mostly arranged in an irregular manner. Concentric rows of vascular canals and laminar organization of the tissue are only found in anteater bones. The long bones of adult specimens are marked by dense Haversian bone, a feature that has been noted for most groups of mammals. In the long bones of armadillos, secondary osteons have an oblique orientation within the three-dimensional bone tissue, thus resulting in their irregular shape when the bones are sectioned transversely. Secondary remodeling is generally more extensive in large taxa than in small taxa, and this could be caused by increased loading. Lines of arrested growth are assumed to be present in all specimens, but they are restricted to the outermost layer in bones of armadillos and are often masked by secondary remodeling in large taxa. Parameters of bone compactness show a pattern in the femur that separates Cingulata and Pilosa (Folivora and Vermilingua, with cingulates having a lower compactness than pilosans. In addition, cingulates show an allometric relationship between humeral and femoral bone compactness.

Exceptionally long 5' UTR short tandem repeats specifically linked to primates.

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Namdar-Aligoodarzi, P; Mohammadparast, S; Zaker-Kandjani, B; Talebi Kakroodi, S; Jafari Vesiehsari, M; Ohadi, M

2015-09-10

We have previously reported genome-scale short tandem repeats (STRs) in the core promoter interval (i.e. -120 to +1 to the transcription start site) of protein-coding genes that have evolved identically in primates vs. non-primates. Those STRs may function as evolutionary switch codes for primate speciation. In the current study, we used the Ensembl database to analyze the 5' untranslated region (5' UTR) between +1 and +60 of the transcription start site of the entire human protein-coding genes annotated in the GeneCards database, in order to identify "exceptionally long" STRs (≥5-repeats), which may be of selective/adaptive advantage. The importance of this critical interval is its function as core promoter, and its effect on transcription and translation. In order to minimize ascertainment bias, we analyzed the evolutionary status of the human 5' UTR STRs of ≥5-repeats in several species encompassing six major orders and superorders across mammals, including primates, rodents, Scandentia, Laurasiatheria, Afrotheria, and Xenarthra. We introduce primate-specific STRs, and STRs which have expanded from mouse to primates. Identical co-occurrence of the identified STRs of rare average frequency between 0.006 and 0.0001 in primates supports a role for those motifs in processes that diverged primates from other mammals, such as neuronal differentiation (e.g. APOD and FGF4), and craniofacial development (e.g. FILIP1L). A number of the identified STRs of ≥5-repeats may be human-specific (e.g. ZMYM3 and DAZAP1). Future work is warranted to examine the importance of the listed genes in primate/human evolution, development, and disease. Copyright © 2015 Elsevier B.V. All rights reserved.

Los mamíferos fósiles del distrito de Puente de Piedra (Xenarthra, Glyptodontidae; Artiodactyla, Camelidae, Lamini), Grecia, provincia de Alajuela, Costa Rica

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Eduardo A Pérez

2013-01-01

Se presenta el segundo registro fósil de la familia Camelidae, y primero del género Palaeolama para Costa Rica, hallado junto a placas de Glyptotherium. Esta asociación proporciona nuevos datos del Gran Intercambio Biótico Americano. El fósil del Camelidae consiste de un metapodial posterior izquierdo. Con base en estudios anteriores de hallazgos de mamíferos fósiles en localidades cercanas se le asigna una edad Irvingtoniano Temprano.

Morfologia, topografia e irrigação do coração do Tamandua tetradactyla

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G.S. Pinheiro

2014-08-01

Full Text Available O Tamandua tetradactyla é uma espécie da ordem Xenarthra que apresenta coloração amarelada na cabeça, nos membros e na parte anterior do dorso, sendo o restante do corpo negro, formando uma espécie de colete, por isso também é chamado de "tamanduá-de-colete". Objetivou-se descrever a morfologia, a topografia e a irrigação cardíaca do Tamandua tetradactyla. Foram utilizados quatro espécimes jovens, provenientes da área de Mina Bauxita - Paragominas, Pará, que foram doados à Universidade Federal Rural da Amazônia - UFRA, após morte por atropelamento. O sistema arterial foi preenchido com látex contrastado, e os animais foram fixados em uma solução de formaldeído a 10%. A cavidade torácica foi acessada e permitiu a análise topográfica do coração, com posterior mensuração, descrição morfológica e vascular. O coração estava localizado entre o terceiro e o quinto espaço intercostal, apresentando duas artérias coronárias, direita e esquerda, que se originaram do seio aórtico. O tipo de irrigação para esta espécie variou entre a do tipo equilibrada e a direita. Nos sulcos coronários, localizavam-se os ramos circunflexos das artérias coronárias, originando os ramos interventriculares paraconal e subsinuoso. Além das quatro câmaras cardíacas, observaram-se também as valvas tricúspide e bicúspide, cordas tendíneas, trabéculas carnosas e trabéculas septo marginal, músculos papilares nas câmaras ventriculares e músculos pectiniformes nas câmaras atriais.

Anatomy and histology of the male reproductive tract and spermatogenesis fine structure in the lesser anteater (Tamandua tetradactyla, Myrmecophagidae, Xenarthra): morphological evidences of reproductive functions.

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Rossi, L F; Luaces, J P; Aldana Marcos, H J; Cetica, P D; Perez Jimeno, G; Merani, M S

2013-08-01

The anatomy and histology of the male genital tract of the lesser anteater were studied. Fine details of spermatozoa regarding their genesis and morphology were also studied in six adult specimens. The testes lie in the pelvic cavity. The deferent duct emerges from the epididymis and opens into the ejaculatory duct, which drains into the membranous urethra. Accessory glands (prostate, seminal vesicle and bulbourethral gland) are histologically similar to those described in other mammals. The short penis presents an urethral orifice, while the corpus spongiosum becomes thinner at the end indicating the absence of a histologically defined glans. The seminiferous epithelium shows: (1) Sertoli cells with deep nuclear indentations, (2) spermatogonia with crusty-like chromatin, (3) spermatocytes at different stages of maturation and (4) three morphologically distinct stages of spermatid differentiation according to nuclear shape, acrosome development and chromatin condensation. Sperm heads appear oval. The length of the spermatozoa averages 67.33 ± 1.60 μm. Two specimens with inactive spermatogenesis were azoospermic. Their testes and epididymis presented sizes smaller than those with active spermatogenesis. These studies together with others in anteaters may contribute to successful breeding in conservation programmes. © 2012 Blackwell Verlag GmbH.

Knuckle-walking anteater: a convergence test of adaptation for purported knuckle-walking features of African Hominidae.

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Orr, Caley M

2005-11-01

Appeals to synapomorphic features of the wrist and hand in African apes, early hominins, and modern humans as evidence of knuckle-walking ancestry for the hominin lineage rely on accurate interpretations of those features as adaptations to knuckle-walking locomotion. Because Gorilla, Pan, and Homo share a relatively close common ancestor, the interpretation of such features is confounded somewhat by phylogeny. The study presented here examines the evolution of a similar locomotor regime in New World anteaters (order Xenarthra, family Myrmecophagidae) and uses the terrestrial giant anteater (Myrmecophaga tridactyla) as a convergence test of adaptation for purported knuckle-walking features of the Hominidae. During the stance phase of locomotion, Myrmecophaga transmits loads through flexed digits and a vertical manus, with hyperextension occurring at the metacarpophalangeal joints of the weight-bearing rays. This differs from the locomotion of smaller, arboreal anteaters of outgroup genera Tamandua and Cyclopes that employ extended wrist postures during above-branch quadrupedality. A number of features shared by Myrmecophaga and Pan and Gorilla facilitate load transmission or limit extension, thereby stabilizing the wrist and hand during knuckle-walking, and distinguish these taxa from their respective outgroups. These traits are a distally extended dorsal ridge of the distal radius, proximal expansion of the nonarticular surface of the dorsal capitate, a pronounced articular ridge on the dorsal aspects of the load-bearing metacarpal heads, and metacarpal heads that are wider dorsally than volarly. Only the proximal expansion of the nonarticular area of the dorsal capitate distinguishes knuckle-walkers from digitigrade cercopithecids, but features shared with digitigrade primates might be adaptive to the use of a vertical manus of some sort in the stance phase of terrestrial locomotion. The appearance of capitate nonarticular expansion and the dorsal ridge of the

Resolution among major placental mammal interordinal relationships with genome data imply that speciation influenced their earliest radiations

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Janke Axel

2008-05-01

Full Text Available Abstract Background A number of the deeper divergences in the placental mammal tree are still inconclusively resolved despite extensive phylogenomic analyses. A recent analysis of 200 kbp of protein coding sequences yielded only limited support for the relationships among Laurasiatheria (cow, dog, bat and shrew, probably because the divergences occurred only within a few million years from each other. It is generally expected that increasing the amount of data and improving the taxon sampling enhance the resolution of narrow divergences. Therefore these and other difficult splits were examined by phylogenomic analysis of the hitherto largest sequence alignment. The increasingly complete genome data of placental mammals also allowed developing a novel and stringent data search method. Results The rigorous data handling, recursive BLAST, successfully removed the sequences from gene families, including those from well-known families hemoglobin, olfactory, myosin and HOX genes, thus avoiding alignment of possibly paralogous sequences. The current phylogenomic analysis of 3,012 genes (2,844,615 nucleotides from a total of 22 species yielded statistically significant support for most relationships. While some major clades were confirmed using genomic sequence data, the placement of the treeshrew, bat and the relationship between Boreoeutheria, Xenarthra and Afrotheria remained problematic to resolve despite the size of the alignment. Phylogenomic analysis of divergence times dated the basal placental mammal splits at 95–100 million years ago. Many of the following divergences occurred only a few (2–4 million years later. Relationships with narrow divergence time intervals received unexpectedly limited support even from the phylogenomic analyses. Conclusion The narrow temporal window within which some placental divergences took place suggests that inconsistencies and limited resolution of the mammalian tree may have their natural explanation in

Waking the undead: Implications of a soft explosive model for the timing of placental mammal diversification.

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Springer, Mark S; Emerling, Christopher A; Meredith, Robert W; Janečka, Jan E; Eizirik, Eduardo; Murphy, William J

2017-01-01

The explosive, long fuse, and short fuse models represent competing hypotheses for the timing of placental mammal diversification. Support for the explosive model, which posits both interordinal and intraordinal diversification after the KPg mass extinction, derives from morphological cladistic studies that place Cretaceous eutherians outside of crown Placentalia. By contrast, most molecular studies favor the long fuse model wherein interordinal cladogenesis occurred in the Cretaceous followed by intraordinal cladogenesis after the KPg boundary. Phillips (2016) proposed a soft explosive model that allows for the emergence of a few lineages (Xenarthra, Afrotheria, Euarchontoglires, Laurasiatheria) in the Cretaceous, but otherwise agrees with the explosive model in positing the majority of interordinal diversification after the KPg mass extinction. Phillips (2016) argues that rate transference errors associated with large body size and long lifespan have inflated previous estimates of interordinal divergence times, and further suggests that most interordinal divergences are positioned after the KPg boundary when rate transference errors are avoided through the elimination of calibrations in large-bodied and/or long lifespan clades. Here, we show that rate transference errors can also occur in the opposite direction and drag forward estimated divergence dates when calibrations in large-bodied/long lifespan clades are omitted. This dragging forward effect results in the occurrence of more than half a billion years of 'zombie lineages' on Phillips' preferred timetree. By contrast with ghost lineages, which are a logical byproduct of an incomplete fossil record, zombie lineages occur when estimated divergence dates are younger than the minimum age of the oldest crown fossils. We also present the results of new timetree analyses that address the rate transference problem highlighted by Phillips (2016) by deleting taxa that exceed thresholds for body size and lifespan

Chromosome painting in the manatee supports Afrotheria and Paenungulata

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Zori Roberto T

2007-01-01

Full Text Available Abstract Background Sirenia (manatees, dugongs and Stellar's sea cow have no evolutionary relationship with other marine mammals, despite similarities in adaptations and body shape. Recent phylogenomic results place Sirenia in Afrotheria and with elephants and rock hyraxes in Paenungulata. Sirenia and Hyracoidea are the two afrotherian orders as yet unstudied by comparative molecular cytogenetics. Here we report on the chromosome painting of the Florida manatee. Results The human autosomal and X chromosome paints delimited a total of 44 homologous segments in the manatee genome. The synteny of nine of the 22 human autosomal chromosomes (4, 5, 6, 9, 11, 14, 17, 18 and 20 and the X chromosome were found intact in the manatee. The syntenies of other human chromosomes were disrupted in the manatee genome into two to five segments. The hybridization pattern revealed that 20 (15 unique associations of human chromosome segments are found in the manatee genome: 1/15, 1/19, 2/3 (twice, 3/7 (twice, 3/13, 3/21, 5/21, 7/16, 8/22, 10/12 (twice, 11/20, 12/22 (three times, 14/15, 16/19 and 18/19. Conclusion There are five derived chromosome traits that strongly link elephants with manatees in Tethytheria and give implicit support to Paenungulata: the associations 2/3, 3/13, 8/22, 18/19 and the loss of the ancestral eutherian 4/8 association. It would be useful to test these conclusions with chromosome painting in hyraxes. The manatee chromosome painting data confirm that the associations 1/19 and 5/21 phylogenetically link afrotherian species and show that Afrotheria is a natural clade. The association 10/12/22 is also ubiquitous in Afrotheria (clade I, present in Laurasiatheria (clade IV, only partially present in Xenarthra (10/12, clade II and absent in Euarchontoglires (clade III. If Afrotheria is basal to eutherians, this association could be part of the ancestral eutherian karyotype. If afrotherians are not at the root of the eutherian tree, then the 10

Chagas disease: control, elimination and eradication. Is it possible?

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Jose Rodrigues Coura

2013-12-01

Full Text Available From an epidemiological point of view, Chagas disease and its reservoirs and vectors can present the following characteristics: (i enzooty, maintained by wild animals and vectors, with broad occurrence from southern United States of America (USA to southern Argentina and Chile (42ºN 49ºS, (ii anthropozoonosis, when man invades the wild ecotope and becomes infected with Trypanosoma cruzi from wild animals or vectors or when the vectors and wild animals, especially marsupials, invade the human domicile and infect man, (iii zoonosis-amphixenosis and exchanged infection between animals and humans by domestic vectors in endemic areas and (iv zooanthroponosis, infection that is transmitted from man to animals, by means of domestic vectors, which is the rarest situation in areas endemic for Chagas disease. The characteristics of Chagas disease as an enzooty of wild animals and as an anthropozoonosis are seen most frequently in the Brazilian Amazon and in the Pan-Amazon region as a whole, where there are 33 species of six genera of wild animals: Marsupialia, Chiroptera, Rodentia, Edentata (Xenarthra, Carnivora and Primata and 27 species of triatomines, most of which infected with T. cruzi . These conditions place the resident populations of this area or its visitors - tourists, hunters, fishermen and especially the people whose livelihood involves plant extraction - at risk of being affected by Chagas disease. On the other hand, there has been an exponential increase in the acute cases of Chagas disease in that region through oral transmission of T. cruzi , causing outbreaks of the disease. In four seroepidemiological surveys that were carried out in areas of the microregion of the Negro River, state of Amazonas, in 1991, 1993, 1997 and 2010, we found large numbers of people who were serologically positive for T. cruzi infection. The majority of them and/or their relatives worked in piassava extraction and had come into contact with and were stung by

Programa de Pós-Graduação em Geologia - Dissertações Defendidas 1999 - Mestrado - Instituto de Geociências - Universidade Federal do Rio de Janeiro

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1999-01-01

ção humana, face as variáveis ambientais reinantes na área de estudo.. Nome: Kleberson de Oliveira Porpino Orientador: Lílian Paglarelli Bergqvist Título: Estudo dos Cingulata (Xenarthra, Mammalia Fósseis Depositados no Museu Câmara Cascudo, Natal - RN Resumo: A ordem Cingulata, característica da América do Sul, é bem representada nos depósitos pleistocênicos do Brasil, onde ocorrem formas edêmicas em associação à outras cuja distribuição geográfica não se restringe ao território brasileiro. Neste trabalho efetua-se um estudo e revisão do material atribuído à ordem Cingulata e depositado no acervo do Museu Câmara Cascudo. Os fósseis foram coletados em depósitos do tipo “tanque” e em grutas calcárias, nas localidades de Lagoa do Santo, Lágea Formosa e Lajedo da Escada, situadas, respectivamente, nos municípios de Currais Novos, São Rafael e Baraúnas, no estado do Rio Grande do Norte. As peças incluem diversos osteodermos e fragmentos de carapaça bem como material pós-craniano endoesquelético diverso. A partir deste estudo identificam-se dois gêneros e três espécies: Propraopus sp., Panochthus sp., Panochthus greslebini, Panochthus jaguaribensis e Glyptodon clavipes. A presença do gênero Propraopus, cujos registros no Brasil até então limitam-se principalmente ao sudeste e sul do país, constitui a primeira ocorrên- 110 Anuário do Instituto de Geociências - UFRJ Volume 22 / 1999 cia do táxon no nordeste brasileiro. A morfologia observada no material pertencente a P. greslebini, P. jaguaribensis e G. clavipes é compatível com o que se conhece a respeito destas espécies. Ossos ainda não descritos para as duas primeiras espécies foram encontrados dentre os fósseis estudados, ampliando o conhecimento morfológico dos Panochthini do nordeste brasileiro. Diversas características morfométricas e anatômicas das peças atribuídas a Propraopus sp. apontam para a possibilidade de tratar-se de uma espécie distinta daquelas at