Navegando por Assunto "Osteologia"

Agora exibindo 1 - 4 de 4

Acesso aberto (Open Access)
Considerações sobre a anatomia funcional e adptativa de alguns sigmodontinae (Mammalia : Rodentia : Muridae)
(Universidade Federal do Pará, 2002-10-29) MELO, Cláudia Cristina de Sousa de Melo; TOLEDO, Peter Mann de; http://lattes.cnpq.br/3990234183124986
Among the mammals, the little rodents makes up a singular group. These animals have been in full evolutive process due to their capacity of reproducing and adapting to different habitats. Philogeneticly, the group still hasn't a sure characteristic and is very similar morphologically to rodents Sigmodontinae from Serra dos Carajás. Through this study of external features and some banes from post-cranium related to motions habit, we beheld: 1) The choice of the habitat in Serra dos Carajás area among the rodents seems not to be related to a phylogenetic standard; 2) It wasn't possible to set a relationship between ecological features and main morphological shape from post-cranium related to body-shape among Sigmodontinae; 3) the morphology of úmero and femur have a strong Phylogenetic sign which is another feature of subfamily Sigmodontinae; 4) the signs intermembal, crural e branquial weren't effective to identify the many way of motions among the rodents Sigmodontinae.
Acesso aberto (Open Access)
A morfologia de Stenocercus dumerilii Steindachner (1867) (Squamata, Iguanidae) e suas implicações filogenéticas
(Universidade Federal do Pará, 2004-05-18) HERNÁNDEZ RUZ, Emil José; ÁVILA-PIRES, Teresa Cristina Sauer de; http://lattes.cnpq.br/1339618330655263
The objetive of this study was to include the lizard Stenocercus dumerilii (Steindachner, 1867) in the phylogenetic context of Tropidurinae*. Scale morphology, cranial anatomy, scapular girdle, abdominal skeleton, and hemipenis are described. Emphasis is given to characters used in phylogenetic studies including the genus Stenocercus. Sixty-five preserved specimens, two cleared and stained specimens, and two distended hemipenis have been examined. The characteristics studied agree with the generic placement of the species, considering its present definition. On the other hand, the species is unique within the genus Stenocercus by having only one pair of xiphisternal ribs, a depressed tail, postsupraciliar scales projected in the form of a horn (together with S. tricristatus), and enlarged parietal, postparietal and occipital scales forming a longitudinal sequence. Contrary to what has been generally considered, this species does not agree with the characteristics o f the informal "Ophryoessoides group". The main characteristics of S. dumerilii that exclude it from this species group are the arrangement of supraoculars and posterior head scales, and the distance between the pairs of post-xiphisternal ribs. It is concluded that S. dumerilii fits well within Tropidurinae* and the genus Stenocercus, but it is not part of the "Ophryoessoides group".
Acesso aberto (Open Access)
Morfologia funcional e desenho corporal da cintura pélvica e membros posteriores dos Tamanduás (Mammalia : Xenarthra : Myrmecophagidae)
(Universidade Federal do Pará, 2001-12-20) OLIVEIRA, Manuela França de; TOLEDO, Peter Mann de; http://lattes.cnpq.br/3990234183124986
Among mammals, xenarthrans are certainly a very singular group with respect to its morphology, physiology, and feeding and locomotory habits. Within the order Xenarthra, the family Myrmecophagidae has received little attention in papers on functional morphology and biomechanics, especially concerning the hindlimbs. In order to contribute to the biological knowledge on the morphofunctional and biomechanical natures of the hindlimbs (femur and tibia) and peivic girdie in these animais [genera: Cyclopes (silky anteater), Tamandua (lesser anteater) and Myrmecophaga (giant anteater)], this paper aims at a comparative and descriptive osteological study of those structures, emphasizing the main points reflecting biomechanical functionality related to locomotory habits. In addition to osteological descriptions, 23 post-cranial measurements for the pelvic girdle, femur, tibia, humerus, and radius were taken. From those measurements, thirteen osteometric indexes were obtained and proved effective in the morphofunctional characterization of the three genera, biomechanically separating them according to their respective locomotory styles.
Acesso aberto (Open Access)
Revisão taxonômica do gênero Hassar Eigenmann & Eigenmann, 1888, com a descrição osteológica de Hassar orestis (Steindachner, 1875) (Siluriformes, Doradidae)
(Universidade Federal do Pará, 2007-04-27) FAYAL, Danielle Freitas; WOSIACKI, Wolmar Benjamin; http://lattes.cnpq.br/0040413891328104
The genus Hassar (Doradidae) is a monophyletic group of Neotropical Siluriformes. The present paper is a taxonomic revision of the species of Hassar, with an osteological description of type-species H. orestis. This study was based on the survey and analysis of morphological, morphometric, meristic and color pattern characters for the recognition of the valid species and consequent diagnosis and redescriptions. The specimens analyzed (n=727), from domestic and foreign institutions, included individuals preserved in alcohol, prepared as dry skeletons, cleared and stained, x-rayed and/or photographed. The specimens were observed directly or with a stereomicroscope and camera lucida. Measures were made, preferentially, on the left side. The osteological description of Hassar orestis was based on the analysis of 23 specimens and divided into functional osteological groups namely: neurocranium, mandibular arch, hyoid arch, branchial arches, axial skeleton, nucal plates and dorsal fin, laterosensory system and appendicular skeleton. The results show Hassar as being composed by two species: H. orestis and H. affinis. Hassar orestis has H. ucayalensis as synonym. Hassar affinis has H. wilderi, H. iheringi and H. woodi as synonyms. Hassar orestis and H. affinis differ from each other by the position of the first medial thorn (at the infranucal scute or between the 1st and 8th lateral scute vs. between the 9th and 16th lateral scute), by the number of lateral scutes with a medial thorn (24 to 33 vs. 18 to 23 respectively) and by the condition filiform marginal diverticula of the swimbladder (distinctly larger vs. reduced or absent respectively). The adults (>14 cm) of H. orestis and H. affinis are distinguished by of the depth caudal peduncle (4.11-5.71% SL vs. 5.73 -7.63% SL respectively) and by the size of the adipose eyelid (conspicuous and elongate over the anterior border of the eyes vs. tenuous over the anterior border of the eyes respectively). No morphological, morphometric and meristic differences among juveniles and adults of the same species were found. Both species present the same color pattern and share a subterminal black spot on the first rays of the dorsal fin, but some specimens of H. affinis present a terminal black spot. The presence of a cartilaginous extension on prolongation in the first ray of the dorsal fin, in some males of H. orestis, confirmed the notion of sexual dimorphism for this species. Specimens of H. orestis from the Amazon, Solimões, and Negro rivers differ from the population from the Branco river and from the Essequibo and Orinoco basins by the presence or absence of thorns on the tympanic scutes and on the infranucal scute. No differences were found between the swimbladders of those populations. The distribution of H. affinis was extended for the rivers Solimões, Tapajós, upper and lower Xingu, Tocantins, Araguaia, Parnaíba and Pindaré-Mearim System. Hassar affinis and H. orestis have a wide, partially disjunct distribution, with an area of sympatry. The osteological description of the H. orestis provides a better anatomical understanding of the group, and basic data for future on anatomy, ontogeny, ecomorphology and systematics and taxonomy.