895 resultados para CRANIAL OSTEOLOGY
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Squamates (lizards, snakes and amphisbaenians) are represented by a large number of species distributed among a wide variety of habitats. Changes in body plan related to a fossorial habit are a frequent trend within the group and many morphological adaptations to this particular lifestyle evolved convergently in nonrelated species, reflecting adaptations to a similar habitat. The fossorial lifestyle requires an optimal morphological organization for an effective use of the available resources. Skeleton arrangement in fossorial squamates reflects adaptations to the burrowing activity, and different degrees of fossoriality can be inferred through an analysis of skull morphology. Here, we provide a detailed description of the skull morphology of three fossorial gymnophthalmid species: Calyptommatus nicterus, Scriptosaura catimbau, and Nothobachia ablephara. J. Morphol. 271: 1352-1365, 2010. (C) 2010 Wiley-Liss, Inc.
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Recognizing the scarcity of anatomical and phylogenetic studies on Crotophaginae, the authors set Out to add to the anatomical knowledge of the group based on a detailed description of cranial osteology. Another objective was to verify whether this source of data could be used to infer relationships by performing the first cladistic analysis of the four species of Crotophaginae. The shortest-length cladogram (consistency index = 1.0) indicated that cranial osteology is an important source of characters for cladistic analysis of cuckoos. The findings corroborated the monophyly of Crotophaginae, showing that Guira guira is (lie most divergent and plesiomorphic taxon and that Crotophaga ani and Crotophaga sulcirostris are more closely related to each other than to Crotophaga major.
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Momotidae (motmots) is found throughout Latin America between Mexico and northern Argentina. Given the absence of detailed studies of cranial osteology of Momotidae in the literature, this article presents a comprehensive description of the variation of the cranial osteology in all nine species of Momotidae and compares the results with published studies of other families of Coraciiformes and families in other orders. In addition, the cranial structures described are related to ecological and behavioral aspects of Momotidae. The cranial osteology of Baryphthengus ruficapillus is described in detail and compared with other species of Momotidae. The results indicate the presence in Momotidae of modified cranial structures, among which the most conspicuous are the frontal, lacrimal, squamosal, orbital, and laterosphenoid regions, as well as the palatine, upper jaw, pterygoid, and mandible. (C) 2003 Wiley-Liss, Inc.
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The Picini is composed of 26 species of woodpeckers from the old world that are grouped into seven genera. Given the absence of detailed studies on the cranial osteology of the Picini, the purpose of this study is to describe the cranial osteology of 14 species of Picini from six genera and to compare these species with each other, with other species of woodpeckers and with other bird groups. The results of the analysis of the bone structures of the skull of the Picini indicate that there are seven outstanding characteristic of bones involved in the functional mechanistics of the jaw apparatus. In the ossa cranii, these include the frontal overhang, the postorbital process, the extension of the parietal versus the frontal region and the temporal fossa. In the ossa faciei, these include the rostral expansion of the pterygoid, the ventral palatine fossa and the orbital process of the quadrate bone. For all of the structures associated with the cranial osteology of the investigated species, there is a clear distinction between the species of the genus Picus and the other species studied. Blythipicus rubiginosus, Chrysocolaptes lucidus, Reinwardtipicus validus, Gecinulus viridis and the species of the genus Dinopium exhibit additional particularities. © 2012 The Royal Swedish Academy of Sciences.
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The Meiglyptini comprise eight species grouped into three genera: Meiglyptes and Mulleripicus, with three species each, and Hemicircus, with two species. The aim of the present study was to describe the cranial osteology of six species and three genera of Meiglyptini and to compare them to each other, as well as with other species of woodpeckers and other bird groups. The cranial osteology varied among the investigated species, but the most markedly distinct characteristics were: (1) a frontal overhang is only observed in the middle portion of the frontale of H. concretus; (2) the Proc. zygomaticus and suprameaticus are thick and long in species of the genus Mulleripicus, but short in other species; (3) the Pes pterygoidei is relatively larger in species of the genus Mulleripicus, while it is narrow, thin and relatively smaller in species of the genus Meiglyptes and indistinct in H. concretus; (4) the bony projection of the ectethmoidale is relatively short and thin in species of Mulleripicus and more developed in H. concretus. It appears that the greatest structural complexity of the cranial osteology is associated with the birds' diet, with the frugivorous H. concretus being markedly different from the insectivorous species.
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The cranial osteology of Micrastur gilvicollis (Vieillot, 1817), Micrastur ruficollis (Vieillot, 1817) and Micrastur semitorquatus (Vieillot, 1817) is comparatively and meticulously described to characterize each of the species and to determine which traits the species have in common and which are distinct. These traits will be used a posteriori for phylogenetic analysis. Our results indicate that M. gilvicollis and M. ruficollis are closely related, as they share a large number of traits, including a lacrimal bone with a distal portion that is approximately half as long as the proximal portion and a parasphenoid rostrum that covers 50% of the distance between the occipital condyle and pterygoid. Similarly, M. gilvicollis and M. semitorquatus both have a partially fused craniofacial flexion zone. In both M. ruficollis and M. semitorquatus, the symphyseal region of the mandible is 1/5 the total length of the mandible. The diagnostic traits for each of these species are as follows: a) in M. gilvicollis, the interorbital distance is 1/3 the length of the parietal, and the zygomatic process stretches 1/5 of the distance from the orbital arch to the jugal arch; b) in M. ruficollis, the interorbital distance is 2/5 of the length of the parietal and the zygomatic process extends 1/4 of the distance from the orbital arch to the jugal arch; and c) in M. semitorquatus, the interorbital distance is 3/7 the length of the parietal and the distal portion of the lacrimal is 1/3 the length of the proximal portion. Among the three species, M. gilvicolis and M. ruficollis share the most traits, which leads us to infer that these species are more closely related to one another than they are to M. semitorquatus. Phylogenetic analysis performed a posteriori may confirm the relationship between these three species.
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The six peculiar multicusped teeth described here were collected from sediments of the Upper Cretaceous of Sao Jose do Rio Preto Formation, near Ibira (northeastern Sao Paulo, Brazil). Their bulbous crowns are slightly labio-lingual compressed, and bear a main plus two accessory cusps, which conceal a well developed cingulum. Wear facets are seen on the main and distal accessory cusps. Comparison to the known Crocodyliformes with multicusped teeth show that the new material is not referable to ""protosuchians"" or eusuchians, nor related to two unnamed forms from Morocco and ""notosuchians"" such as Uruguaysuchus, Chiamaerasuchus, and Simosuchus. On the other hand, possible affinities with Candidodon and Malawisuchus were maintained based on shared traits. This includes teeth with the main cusp and some accessory cusps arranged in more than one axis, a previously defined unambiguous apomorphy of the putative clade composed of Candidodon plus Malawisuchus. The term Candidodontidae can be applied to this group, and defined as all taxa closer to Candidodon itapecuruensis than to Notosuchus terrestris, Uruguaysuchus aznarezi, Comahuesuchus brachybuccalis, Sphagesaurus huenei, Baurusuchus pachecoi, and Crocodylus niloticus. (C) 2009 Elsevier Ltd. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Dez famílias são tradicionalmente agrupadas na Ordem Coraciiformes, Alcedinidae (martins-pescadores), Momotidae (udus e juruvas), Todidae ( todies ), Meropidae (abelharucos), Coraciidae (rolieiros), Brachypteraciidae ( ground-rollers ), Leptosomidae ( cuckoo-rollers ), Phoeniculidae ( woodhoopoes ), Upupidae (poupas-comuns) e Bucerotidae (calaus), mas não há caracteres na morfologia externa que sejam comuns a todos os membros da ordem. Assim, este trabalho apresenta uma comparação da osteologia craniana das espécies de Coraciiformes com a finalidade de encontrar caracteres osteológicos que possam diagnosticar a ordem ou grupos de táxons de Coraciiformes, servindo ainda como uma fonte de dados para futuras análises filogenéticas. Como constatado por dados da morfologia externa, os caracteres da osteologia craniana ratificaram a diversidade morfológica existente entre os táxons da Ordem Coraciiformes, sendo difícil diagnosticá-la ou encontrar caracteres comuns a todos os seus membros. Apenas dois caracteres são comuns à ordem, tais como a presença da fossa lateroesfenóide e a ausência do processo suprameático, embora tais caracteres também sejam encontrados em outros grupos de aves. Homologias primárias foram encontradas, indicando similaridades entre diversas famílias, tais como: a zona flexória craniofacial é oclusa nos indiviíduos adultos de Coraciidae, Leptosomidae, Phoeniculidae, Upupidae e Bucerotidae; a fossa temporal tem desenvolvimento e profundidade intermediários em Momotidae, Meropidae, Coraciidae, Brachypteraciidae e Bucerotidae; o lacrimal está ausente em Momotidae, fundido com o ectetmóide nos adultos de Upupidae, Phoeniculidae e Bucerotidae, e presente e distinto em Alcedinidae, Todidae, Meropidae, Coraciidae, Brachypteraciidae e Leptosomidae; e o processo retroarticular da mandíbula é desenvolvido em Upupidae, Phoeniculidae e Bucerotidae.
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Micrastur semitorquatus, popularly known as Collared Forest-Falcon is an inhabitant of the rainforests of the Neotropical Region. Studies on the cranial osteology are scarce in the literature. To increase the knowledge about the anatomy of this species its cranial osteology was described and compared with other species of birds of prey. Three specimens of M. semitorquatus were examined at the Bird Division of the osteological collection at the Smithsonian National Museum of Natural History (USNM), Washington, DC (USNM: 245788, USNM 013493 and USNM 289773). Although the relationship between the form of a structure and its function is not fully established, many of the adaptations of the skull of M. semitorquatus may be related to this lifestyle and behavior, such as narrowing of the interorbital width, the robustness of pila supranasalis coupled with the prokinesis of the skull, a process developed post-orbital, and palatine expansion. In addition, the cranial osteology of M. semitorquatus can provide useful characters for cladistic analysis, sustaining the hypothesis of phylogenetic relationships with other species of the same genus or the same family.
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Pós-graduação em Ciências Biológicas (Zoologia) - IBRC
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Foi analisado um total de 249 espécimes das subespécies de Liophis reginae que ocorrem no Brasil (Liophis reginae macrosomus e Liophis reginae semilineatus), com o objetivo de caracterizar morfologicamente os dois táxons e verificar a validade de Liophis oligolepis, táxon considerado sinônimo de Liophis reginae semilineatus. Foram considerados 22 dados merísticos e 18 morfométricos. Os complexos osteológicos e cefálicos, assim como os hemipênis foram analisados comparativamente entre os táxons. Foram identificadas, utilizando MANOVA, diferenças sexuais significativas em variáveis mensuradas da cabeça e do corpo. Uma análise da função discriminante (AFD) foi utilizada em sexos separados para maximizar a separação, num espaço rnultivariado, dos três táxons definidos a priori: Liophis regime semilineatus, Liophis reginae macrosomus e Liophis oligolepis. Os escores dos espécimes machos separaram claramente Liophis reginae semilineatus de Liophis oligolepis no eixo da primeira função discriminante e Liophis reginae semilineatus de Liophis reginae macrosomus na segunda função. Em fêmeas, a primeira função discriminante separou Liophis oligolepis de Liophis reginae semilineatus e Liophis reginae macrosomus. Na AFD de Liophis oligolepis e Liophis reginae semilineatus, considerando os dois sexos juntos, houve uma diferenciação entre os dois táxons na primeira função discriminante. A mesma análise foi feita para Liophis reginae semilineatus e Liophis reginae rnacrosomus, sendo observado uma separação destes táxons na primeira função discriminante. Verificou-se alguns exemplares de Liophis reginae semilineatus e Liophis reginae macrosomus além das áreas de distribuição registradas para essas subespécies. Para verificar se estes e os outros exemplares, ocorrentes nas áreas de distribuição citadas em bibliografia, formavam o mesmo grupo, foi feita uma análise da função discriminante. Os resultados indicam que as novas ocorrências pertencem ao mesmo grupo de espécimes previamente estabelecidos. A morfologia hemipeniana não diferiu entre Liophis reginae semilineatus, Liophis oligolepis e Liophis reginae macrosomus. Os três táxons apresentam crânios semelhantes no aspecto geral, porém existem diferenças, no osso parietal de Liophis reginae semilineatus e Liophis oligolepis. O status taxonômico de Liophis oligolepis foi definido na categoria específica com base nos caracteres meristicos, morfométricos e morfológicos. As subespécies Liophis reginae semilineatus e Liophis reginae macrosomus deverão ser reavaliadas no futuro, para a verificação de seus status. Com a análise de mais exemplares e a inclusão de Liophis reginae regime e Liophis reginae zweiftli nas análises.
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As serpentes atuais são tradicionalmente divididas em dois grupos: Alethinophidia, taxonômica e ecologicamente mais diverso e Scolecophidia, grupo de serpentes fossoriais popularmente conhecidas como cobras-cegas, sendo Typhlopidae a família que possui maior número de espécies. Em função do hábito fossorial, os Typhlopidae são pouco representados em coleções cientificas e a escassez de amostras de tecido tem sido um fator limitante para realização de estudos moleculares dessa família. Por isso aspectos da biologia evolutiva como modos de especiação, padrão de diversificação e estruturação geográfica que devido o hábito fossorial e a pouca diferenciação morfológica intra e interespecífica são ainda pouco entendidos. Esse trabalho teve como objetivo analisar a variação morfológica e molecular de Typhlops reticulatus. Para isso foram analisados 314 exemplares de Typhlops, sendo 192 de T. reticulatus. Para análise morfológica foram utilizados caracteres morfométricos, morfológicos (folidose, hemipênis e osteologia craniana). Nas análises moleculares foram sequenciados 21 amostras de T. reticulatus dos genes mitocondriais Coi e Cyt b de diferentes localidades. As árvores filogenéticas foram feitas usando os métodos de Máxima Parcimônia e Máxima Verossimilhança e as relações entre os grupos foram inferidos através de rede de haplótipos. Através da combinação de caracteres moleculares e morfológicos foi possível observar a presença de duas linhagens evolutivas distintas de T. reticulatus: uma ao norte do Rio Amazonas e outra ao sul, esta última descrita como nova espécie nesse trabalho. Durante a análise dos exemplares de Typhlops para esse trabalho foi possível identificar duas novas espécies: Typhlops sp nov. 1 presente no Estado do Maranhão e Typhlops sp nov. 2 proveniente de Manaus, Amazonas. Os resultados desse estudo corroboram a afirmação que espécies com ampla distribuição geográfica podem apresentar diversidade críptica considerável e uma história evolutiva mais complexa do que se imagina.
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The genus Mycteria (Ciconiidae) is composed of species with controversial phylogenetic hypotheses of relationships. This study sought to describe the cranial osteology of the four species included in the genus Mycteria, comparing with representative species from other genera of the family. The monophyly of Mycteria coud be hypothesized based on the following cranial characters: 1) medial process of the mandible medially oriented and 2) pseudo temporal tubercle developed when compared to other species Ciconiidae. Mycteria ibis and M. leucocephala are sister groups supported by: 1) deep temporal fossa, 2) reduced “T” tubercle and 3) expansion of the caudal fossa coanalis relative to other species of Ciconiidae. Among the species studied, the most basal was M. cinerea and the taxon formed by M. ibis and M. leucocephala is sister group of M. americana, sustained by the presence of total fusion of lacrimal and frontal bones, whereas in remaining species of Ciconiidae the suture between these bones is visible.