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Letteratura scientifica selezionata sul tema "Vertebrates Morphology"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 13 febbraio 2022

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Articoli di riviste sul tema "Vertebrates Morphology"

Root, Zachary D., Claire Gould, Margaux Brewer, David Jandzik e Daniel M. Medeiros. "Comparative Approaches in Vertebrate Cartilage Histogenesis and Regulation: Insights from Lampreys and Hagfishes". Diversity 13, n. 9 (10 settembre 2021): 435. http://dx.doi.org/10.3390/d13090435.

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Jawed vertebrates (gnathostomes) have been the dominant lineage of deuterostomes for nearly three hundred fifty million years. Only a few lineages of jawless vertebrates remain in comparison. Composed of lampreys and hagfishes (cyclostomes), these jawless survivors are important systems for understanding the evolution of vertebrates. One focus of cyclostome research has been head skeleton development, as its evolution has been a driver of vertebrate morphological diversification. Recent work has identified hyaline-like cartilage in the oral cirri of the invertebrate chordate amphioxus, making cyclostomes critical for understanding the stepwise acquisition of vertebrate chondroid tissues. Our knowledge of cyclostome skeletogenesis, however, has lagged behind gnathostomes due to the difficulty of manipulating lamprey and hagfish embryos. In this review, we discuss and compare the regulation and histogenesis of cyclostome and gnathostome skeletal tissues. We also survey differences in skeletal morphology that we see amongst cyclostomes, as few elements can be confidently homologized between them. A recurring theme is the heterogeneity of skeletal morphology amongst living vertebrates, despite conserved genetic regulation. Based on these comparisons, we suggest a model through which these mesenchymal connective tissues acquired distinct histologies and that histological flexibility in cartilage existed in the last common ancestor of modern vertebrates.

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Burke, A. C., C. E. Nelson, B. A. Morgan e C. Tabin. "Hox genes and the evolution of vertebrate axial morphology". Development 121, n. 2 (1 febbraio 1995): 333–46. http://dx.doi.org/10.1242/dev.121.2.333.

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A common form of evolutionary variation between vertebrate taxa is the different numbers of segments that contribute to various regions of the anterior-posterior axis; cervical vertebrae, thoracic vertebrae, etc. The term ‘transposition’ is used to describe this phenomenon. Genetic experiments with homeotic genes in mice have demonstrated that Hox genes are in part responsible for the specification of segmental identity along the anterior-posterior axis, and it has been proposed that an axial Hox code determines the morphology of individual vertebrae (Kessel, M. and Gruss, P. (1990) Science 249, 347–379). This paper presents a comparative study of the developmental patterns of homeobox gene expression and developmental morphology between animals that have homologous regulatory genes but different morphologies. The axial expression boundaries of 23 Hox genes were examined in the paraxial mesoderm of chick, and 16 in mouse embryos by in situ hybridization and immunolocalization techniques. Hox gene anterior expression boundaries were found to be transposed in concert with morphological boundaries. This data contributes a mechanistic level to the assumed homology of these regions in vertebrates. The recognition of mechanistic homology supports the historical homology of basic patterning mechanisms between all organisms that share these genes.

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Eilam, David. "Comparative Morphology of Locomotion in Vertebrates". Journal of Motor Behavior 27, n. 1 (marzo 1995): 100–111. http://dx.doi.org/10.1080/00222895.1995.9941703.

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Rossi, Valentina, Maria E. McNamara, Sam M. Webb, Shosuke Ito e Kazumasa Wakamatsu. "Tissue-specific geometry and chemistry of modern and fossilized melanosomes reveal internal anatomy of extinct vertebrates". Proceedings of the National Academy of Sciences 116, n. 36 (19 agosto 2019): 17880–89. http://dx.doi.org/10.1073/pnas.1820285116.

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Recent discoveries of nonintegumentary melanosomes in extant and fossil amphibians offer potential insights into the physiological functions of melanin not directly related to color production, but the phylogenetic distribution and evolutionary history of these internal melanosomes has not been characterized systematically. Here, we present a holistic method to discriminate among melanized tissues by analyzing the anatomical distribution, morphology, and chemistry of melanosomes in various tissues in a phylogenetically broad sample of extant and fossil vertebrates. Our results show that internal melanosomes in all extant vertebrates analyzed have tissue-specific geometries and elemental signatures. Similar distinct populations of preserved melanosomes in phylogenetically diverse vertebrate fossils often map onto specific anatomical features. This approach also reveals the presence of various melanosome-rich internal tissues in fossils, providing a mechanism for the interpretation of the internal anatomy of ancient vertebrates. Collectively, these data indicate that vertebrate melanins share fundamental physiological roles in homeostasis via the scavenging and sequestering of metals and suggest that intimate links between melanin and metal metabolism in vertebrates have deep evolutionary origins.

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Witter, Menno P., Heidi Kleven e Asgeir Kobro Flatmoen. "Comparative Contemplations on the Hippocampus". Brain, Behavior and Evolution 90, n. 1 (2017): 15–24. http://dx.doi.org/10.1159/000475703.

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The hippocampus in mammals is a morphologically well-defined structure, and so are its main subdivisions. To define the homologous structure in other vertebrate clades, using these morphological criteria has been difficult, if not impossible, since the typical mammalian morphology is absent. Although there seems to be consensus that the most medial part of the pallium represents the hippocampus in all vertebrates, there is no consensus on whether all mammalian hippocampal subdivisions are present in the derivatives of the medial pallium in all vertebrate groups. The aim of this paper is to explore the potential relevance of connections to define the hippocampus across vertebrates, with a focus on mammals, reptiles, and birds.

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Henderson, V., e M. J. Song. "Morphology of mitochondria in a teleost, salmo gairdneri". Proceedings, annual meeting, Electron Microscopy Society of America 44 (agosto 1986): 194–95. http://dx.doi.org/10.1017/s0424820100142591.

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Mitochondria have been observed at the ultrastructural level as spherical, oval, or sausagelike. Mitochondria average 0.3 to 1.0 um in diameter and 1.0 to 10.0 μm in length. Mitochondria may exceed these dimensions under certian physiological or pathological conditions. The number of mitochondria may reflect the metabolic condition of cells. Cells with high ATP demands display a large number of mitochondria. High energy requirements characterize muscles in both vertebrates and invertebrates. It has been established that yeast cells have but a single mitochondrion. This investigation was designed to ascertain if the numerous mitochondrial profiles represent a single mitochondrion in vertebrate cells.

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Srikulnath, Kornsorn, Syed Farhan Ahmad, Worapong Singchat e Thitipong Panthum. "Why Do Some Vertebrates Have Microchromosomes?" Cells 10, n. 9 (24 agosto 2021): 2182. http://dx.doi.org/10.3390/cells10092182.

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With more than 70,000 living species, vertebrates have a huge impact on the field of biology and research, including karyotype evolution. One prominent aspect of many vertebrate karyotypes is the enigmatic occurrence of tiny and often cytogenetically indistinguishable microchromosomes, which possess distinctive features compared to macrochromosomes. Why certain vertebrate species carry these microchromosomes in some lineages while others do not, and how they evolve remain open questions. New studies have shown that microchromosomes exhibit certain unique characteristics of genome structure and organization, such as high gene densities, low heterochromatin levels, and high rates of recombination. Our review focuses on recent concepts to expand current knowledge on the dynamic nature of karyotype evolution in vertebrates, raising important questions regarding the evolutionary origins and ramifications of microchromosomes. We introduce the basic karyotypic features to clarify the size, shape, and morphology of macro- and microchromosomes and report their distribution across different lineages. Finally, we characterize the mechanisms of different evolutionary forces underlying the origin and evolution of microchromosomes.

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Schwenk, Kurt, e Günter P. Wagner. "Visualizing vertebrates: new methods in functional morphology". Journal of Experimental Zoology Part A: Ecological Genetics and Physiology 313A, n. 5 (20 aprile 2010): 241–43. http://dx.doi.org/10.1002/jez.608.

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Miyashita, Tetsuto, Michael I. Coates, Robert Farrar, Peter Larson, Phillip L. Manning, Roy A. Wogelius, Nicholas P. Edwards et al. "Hagfish from the Cretaceous Tethys Sea and a reconciliation of the morphological–molecular conflict in early vertebrate phylogeny". Proceedings of the National Academy of Sciences 116, n. 6 (22 gennaio 2019): 2146–51. http://dx.doi.org/10.1073/pnas.1814794116.

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Hagfish depart so much from other fishes anatomically that they were sometimes considered not fully vertebrate. They may represent: (i) an anatomically primitive outgroup of vertebrates (the morphology-based craniate hypothesis); or (ii) an anatomically degenerate vertebrate lineage sister to lampreys (the molecular-based cyclostome hypothesis). This systematic conundrum has become a prominent case of conflict between morphology- and molecular-based phylogenies. To date, the fossil record has offered few insights to this long-branch problem or the evolutionary history of hagfish in general, because unequivocal fossil members of the group are unknown. Here, we report an unequivocal fossil hagfish from the early Late Cretaceous of Lebanon. The soft tissue anatomy includes key attributes of living hagfish: cartilages of barbels, postcranial position of branchial apparatus, and chemical traces of slime glands. This indicates that the suite of characters unique to living hagfish appeared well before Cretaceous times. This new hagfish prompted a reevaluation of morphological characters for interrelationships among jawless vertebrates. By addressing nonindependence of characters, our phylogenetic analyses recovered hagfish and lampreys in a clade of cyclostomes (congruent with the cyclostome hypothesis) using only morphological data. This new phylogeny places the fossil taxon within the hagfish crown group, and resolved other putative fossil cyclostomes to the stem of either hagfish or lamprey crown groups. These results potentially resolve the morphological–molecular conflict at the base of the Vertebrata. Thus, assessment of character nonindependence may help reconcile morphological and molecular inferences for other major discords in animal phylogeny.

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Sakashita, Misaki, Shintaro Yamasaki, Kentaro Yaji, Atsushi Kawamoto e Shigeru Kondo. "Three-dimensional topology optimization model to simulate the external shapes of bone". PLOS Computational Biology 17, n. 6 (16 giugno 2021): e1009043. http://dx.doi.org/10.1371/journal.pcbi.1009043.

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Elucidation of the mechanism by which the shape of bones is formed is essential for understanding vertebrate development. Bones support the body of vertebrates by withstanding external loads, such as those imposed by gravity and muscle tension. Many studies have reported that bone formation varies in response to external loads. An increased external load induces bone synthesis, whereas a decreased external load induces bone resorption. This relationship led to the hypothesis that bone shape adapts to external load. In fact, by simulating this relationship through topology optimization, the internal trabecular structure of bones can be successfully reproduced, thereby facilitating the study of bone diseases. In contrast, there have been few attempts to simulate the external structure of bones, which determines vertebrate morphology. However, the external shape of bones may be reproduced through topology optimization because cells of the same type form both the internal and external structures of bones. Here, we constructed a three-dimensional topology optimization model to attempt the reproduction of the external shape of teleost vertebrae. In teleosts, the internal structure of the vertebral bodies is invariable, exhibiting an hourglass shape, whereas the lateral structure supporting the internal structure differs among species. Based on the anatomical observations, we applied different external loads to the hourglass-shaped part. The simulations produced a variety of three-dimensional structures, some of which exhibited several structural features similar to those of actual teleost vertebrae. In addition, by adjusting the geometric parameters, such as the width of the hourglass shape, we reproduced the variation in the teleost vertebrae shapes. These results suggest that a simulation using topology optimization can successfully reproduce the external shapes of teleost vertebrae. By applying our topology optimization model to various bones of vertebrates, we can understand how the external shape of bones adapts to external loads.

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Più fonti

Tesi sul tema "Vertebrates Morphology"

Brazeau, Martin D. "Endocranial Morphology and Phylogeny of Palaeozoic Gnathostomes (Jawed Vertebrates)". Doctoral thesis, Uppsala universitet, Evolutionär organismbiologi, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-9360.

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Gnathostomes, or jawed vertebrates, make up the overwhelming majority of modern vertebrate diversity. Among living vertebrates, they comprise the chondrichthyans (“cartilaginous fishes” such as sharks, skates, rays, chimaeras) and the osteichthyans (“bony fishes” or bony vertebrates, inclusive of tetrapods). Gnathostomes appear to have originated in the early Palaeozoic Era, but their early fossil record is fairly scant. The best fossils appear first in the Late Silurian and Devonian periods. Much of gnathostome diversity owes to unique adaptations in the internal skeleton of their head (the endocranium). The endocranium is composed of the braincase, jaws, hyoid arch, and branchial arches, which sometimes fossilise when they are composed of bone or calcified cartilage. The purpose of this thesis is to describe and compare the fossilised cranial endoskeletons of a variety of different Palaeozoic gnathostomes. The objective is to test current conceptions of gnathostome interrelationships (i.e. phylogeny) and infer aspects of key morphological transformations that took place during the evolution of Palaeozoic members of this group. Two key areas are examined: the morphology and interrelationships of Palaeozoic gnathostomes and the morphology of the visceral arches in sarcopterygian fishes. New data on the visceral arches are described from the stem tetrapods Panderichthys and rhizodontids. These provide insight into the sequence of character acquisition leading to the tetrapod middle ear. Panderichthys shows key features of the tetrapod middle ear chamber were established prior to the origin fo digited limbs. New morphological data are described from the “acanthodian” fish Ptomacanthus. Ptomacanthus provides only the second example of a well-preserved braincase from any member of this group. It shows dramatic differences from that of its counterpart, Acanthodes, providing new evidence for acanthodian paraphyly. New interpretations of basal gnathostome and osteichthyan phylogeny are presented, challenging or enriching existing views of these problems.

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Lewis, Philip Nigel. "The morphology and function of the peritoneum in lower vertebrates with special reference to teleosts". Thesis, University of Stirling, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391492.

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Jones, Christopher David Stanford. "On the cross-sectional form of the patella in several primates". Title page, table of contents and abstract only, 2003. http://web4.library.adelaide.edu.au/theses/09PH/09phj764.pdf.

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Boonzaier, Julia. "Morphology and mucin histochemistry of the gastrointestinal tracts of three insectivorous mammals : Acomys spinosissimus, Crocidura cyanea and Amblysomus hottentotus". Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20220.

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Thesis (MsCMedSc)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: The gastrointestinal morphology and the distribution of the different types of mucin secreting goblet cells were investigated in three mammalian insectivorous species, namely A. spinosissimus, C. cyanea and A. hottentotus. The aim of the study was to provide a comprehensive morphological comparison between the different species. Another aim was to illustrate and compare the distribution of mucins (neutral, sulfo- and sialomucins) in the gastrointestinal tracts (GITs) of these species, in order to better understand the quality of the biofilm in the GIT. Mucins secreted onto the surface of the GIT have an effect on the colonisation of microflora in the mucosal layer, constructing a biofilm which protects the GIT surface from opportunistic pathogens. The shape, proportional length, and proportional surface areas of the different gastrointestinal regions were recorded and compared in the three species. Histochemical staining methods were used to detect and to distinguish between neutral, sulfo- and sialomucins. The number of goblet cells in the GIT containing each of the above mucins in the epithelium lining the surface or crypts was quantified, and the data expressed as the number of neutral, sulfo- or sialomucin containing goblet cells per mm2 of the surface or crypt epithelium. In all three species the stomach was uncompartmentalised. The internal aspect of the stomach in A. spinosissimus was hemi-glandular, containing stratified squamous epithelium in the fundus, with glandular epithelium in the body and pyloric region. However, C. cyanea and A. hottentotus had wholly glandular stomachs. A. spinosissimus was the only species studied that had a caecum which demonstrated transverse mucosal folds and V-shaped mucosal folds in the proximal colon. Both C. cyanea and A. hottentotus had villi up to the distal part of the GIT. Longitudinal mucosal folds were present in the distal colon. The GITs of both C. cyanea and A. hottentotus showed little morphological differentiation namely a simple, glandular stomach and the lack of a caecum. Mixed (neutral and acid) mucins and mixed acid (sulfo- and sialomucins) mucin secreting goblet cells were prominent mucin cell types in all three mammalian insectivorous species. Despite these general similarities, marked differences were observed in the qualitative expression and distribution of the three types of mucins throughout the GIT. The overall similarity between the three insectivores and other distantly related mammalian species suggests that mixed mucin secreting goblet cell types are prominent contributors to the maintenance of the intestinal biofilm in the majority of mammals, irrespective of their diet or taxonomy.
AFRIKAANSE OPSOMMING: Die bestudering van die morfologie van die spysverteringskanaal (SVK) en die verspreiding van die verskillende musien produserende bekerselle was in drie insek-etende soogdier spesies uitgevoer, naamlik in A. spinosissimus, C. cyanea en A. hottentotus. Die doel van die studie was om „n omvattende morfologiese vergelyking te maak tussen die drie spesies, sowel as om die verspreiding van die verskillende musiene te beskryf in die SVK. Kennis van die verspreiding van die verskillende tipes musiene (neutral, sulfaat en nie-sulfaat bevattende musiene) kan moontlik inligting verskaf aangaande die kwaliteit van die biofilm in the SVK. Die laasgenoemde musiene wat gesekreteer word op die oppervlak van die SVK, bepaal die kolonisasie van die mikroflora in die mukosale laag wat „n biofilm vorm en die SVK beskerm teen patogene. Die vorm, proportionele lengte en proportionele oppervlaks areas van die verskillende SVK gebiede is opgeteken, waarna dit vergelyk is tussen die drie insektivore spesies. Histochemiese kleurings tegnieke is gebruik om die musiene waar te neem en om te onderskei tussen die neutraal, sulfaat en nie-sulfaat bevattende musiene. Die aantal beker selle wat elk van die bogenoemde musiene bevat het, is getel in die oppervlaks epiteel- en kript areas van die SVK. Hierdie data is weergegee as die aantal neutraal, sulfaat en nie-sulfaat bevattende beker selle per oppervlaks epiteel- of kript area (mm2). Die vorm van die maag in al drie spesies was eenvoudig en nie gekompartementaliseer nie. Die interne aspek van die maag in A. spinosissimus het meerlagige plaveisel epiteel in die fundus gehad en klieragtige epiteel in die liggaam en pilorus gedeeltes. Daarbenewens het C. cyanea en A. hottentotus slegs klieragtige epiteel in die maag gehad. A. spinosissimus was die enigste spesie in hierdie studie wat „n sekum gehad het met dwars voue, asook V-vormige mukosale voue in die proksimale kolon. Beide C. cyanea en A. hottentotus het villi tot in die distale gedeelte van die SVK gehad. Longitudinale mukosale voue was teenwoordig in die distale gedeelte van die kolon. Die SVK van beide C. cyanea en A. hottentotus het min morfologiese differensiasie getoon deurdat die spesies „n eenvoudige, klieragtige maag gehad het en geen sekum nie. Gemenge (neutral en suur) musiene asook gemengde suur (sulfaat en nie-sulfaat bevattende) musiene was die dominante musien tipes in the SVK van al drie insek-etende soogdier spesies. Ten spyte van die algemene ooreenkomste, was daar merkwaardige verskille in die getalle en verspreiding van die verskillende musiene in die SVK. Die algemene ooreenkomste tussen die drie insektivore soogdier spesies met soogdiere van ander families, stel voor dat die gemende musien sekreterende beker selle „n prominente bydrae maak tot die onderhoud van die biofilm in the SVK in die meerderheid van soogdiere, ongeag van hul dieet of spesie klassifikasie.

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Sylvester, Jonathan Blaylock. "Brain diversity develops early: a study on the role of patterning on vertebrate brain evolution". Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42744.

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The brain has been one of the central foci in studies of vertebrate evolution. Work in East African cichlids and other emerging fish models like the Mexican cavefish (Astyanax mexicanus) offer new insight on the role of patterning on brain evolution. These fish can be grouped into two major categories according to habitat; for cichlids it is rock-dwelling (known locally as mbuna) and sand-dwelling (non-mbuna) lineage. The brain development of mbuna versus non-mbuna is defined by changes in gene deployment working along the dorsal/ventral (DV) and anterior/posterior (AP) neuraxes, respectively. Comparison of disparate fish ecotypes offer a new perspective of the role of patterning on brain evolution; through the slight and early modification of signal pathways working across 3-D axes, and a subsequent magnifying effect across ontogeny, evolution can generate widespread changes in the brain. To illustrate this patterning model of brain evolution, two comparative studies were done between mbuna and non-mbuna, examining the action of gene pathways that work to pattern the cichlid forebrain. The first study found that non-mbuna cichlids have a more rapid AP expansion of a gene pathway (Wingless) into the presumptive midbrain and diencephalon versus mbuna. These forebrain structures are involved in sight processing and could be of ecological benefit to vision-focused non-mbuna. The second study described a difference within the developing telencephalon. The embryonic telencephalon is split into the pallium, which processes visual signals, and the subpallium, which develops into the olfactory bulbs. Mbuna possess a larger subpallium relative to non-mbuna, which have a larger pallium. This was correlated to a more rapid expansion of another gene pathway (Hedgehog) along the DV axis. The difference in size of the pallial vs. subpallialial comparments between cichlids can be correlated to expanded olfaction in mbuna and vision in non-mbuna adult brains. Overall, East African cichlids are an excellent system to investigate the role of patterning on brain evolution because they allow for the comparison of the earliest patterning events in brain ontogeny between distinct ecotypes. These fish systems link study in brain development to the brain morphology comparisons employed in classic studies of brain evolution.

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Jessee, Lance D., Austin Gause e Blaine W. Schubert. "Intervertebral Variation of North American Pit Vipers (Squamata, Viperidae) Using Geometric Morphometrics". Digital Commons @ East Tennessee State University, 2019. https://dc.etsu.edu/asrf/2019/schedule/95.

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Within Pleistocene cave deposits, snake fossils tend to be relatively common and generally occur as isolated vertebrae. However, the specific, and sometimes generic, identification of isolated snake vertebrae is often hindered by the significant amount of intra- and interspecific variation along the precloacal vertebral column, a subject that has largely been neglected in many fossil snake identifications. Identifications are typically based on the vertebrae of disarticulated modern specimens with preference given to mid-trunk vertebrae. This study utilizes 2-D geometric morphometrics to determine the extent of intervertebral variation along the precloacal vertebral column of North American pit vipers of the genera Crotalus (rattlesnakes) and Agkistrodon (copperheads and moccasins), two closely related genera geographically sympatric in northeast Tennessee and much of the eastern United States with similar vertebral morphologies. The focus of this study is to determine the need for identifying the morphological regionalization of the precloacal vertebral column and determining the regional position of isolated vertebra prior to identification. Using one individual from each genus, every third vertebra was chosen and analyzed in anterior view using geometric morphometrics and relative warp analyses. A discriminant function analysis was then performed to distinguish between the two genera. Viperid fossils from Hickory Tree Cave in northeast Tennessee underwent the same geometric morphometric and discriminant function analyses as a means of identification. It is expected that the relative warp analyses will show some morphological regionalization of the precloacal vertebral column, but may prove to not be significant enough for use in the identification of isolated vertebrae. In that case, comparison to mid-trunk vertebrae for identification may prove accurate. This study also shows the need for more modern skeletal specimens in herpetological collections and the need for preserving the vertebral order of those specimens.

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Gause, Austin R. J., Lance D. Jessee e Blaine W. Schubert. "Geometric Morphometric Analysis of Intervertebral Variation in Colubrid Snakes". Digital Commons @ East Tennessee State University, 2019. https://dc.etsu.edu/asrf/2019/schedule/199.

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Snake vertebrae are common throughout the Cenozoic fossil record, but identification of isolated vertebrae often proves difficult due to inter- and intra-columnar variability. Most fossil identifications are based on comparisons with disarticulated modern specimens, with a focus on mid-trunk vertebrae. One focus of this study was to determine the necessity of identifying a true mid-trunk vertebra prior to identification and to develop a method of locating the columnar position of an isolated vertebra for both modern and fossil identifications. Colubrid genera Farancia and Heterodon were chosen for the analysis because they share distinct morphological similarities, articulated modern specimens were available, and fossil species in these genera need to be reassessed. Every third pre-cloacal vertebra was selected from each specimen to undergo geometric morphometric analysis on its anterior face. Relative warp analyses detailed the inter-columnar variation of each specimen and found that the only significant difference in the column was between the anterior most vertebrae, which are already identifiable, and the remainder of the pre-cloacal vertebrae. Despite concern, the convention of using mid-trunk vertebrae for identification may prove accurate for these genera. Due to Farancia and Heterodon’s vertebral similarities, a discriminant function analysis was utilized to distinguish the two genera from one another. To evaluate this method’s utility in paleontology, vertebrae of two extinct species, Heterodon brevis and Paleofarancia brevispinosus, will undergo identical morphometric and discriminant analyses. This study also emphasizes the need for more modern snake skeletons in collections and the necessity of stringing the vertebral column prior to disarticulation.

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Cotter, Meghan Marie. "Gross Morphology, Microarchitecture, Strength and Evolution of the Hominoid Vertebral Body". Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1295890557.

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Kraig, Sarah Elizabeth. "Morphology and systematic implications of fossil and recent Lamnid shark vertebrae using computerized tomography (CT-scanning)". Diss., Connect to online resource - MSU authorized users, 2008.

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Ramzu, Mohamed Yassin A. "Etude de la regionalisation de la colonne vertebrale en fonction des modes de nage chez les teleosteens. Morphologie, histologie, croissance". Paris 7, 1994. http://www.theses.fr/1994PA077291.

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Chez les teleosteens on definit quatre grands modes de nage axiale (anguilliforme, subcarangiforme, carangiforme, thunniforme). Chacun de ces quatre modes de nage se caracterise par une morphologie differente des poissons et des specificites hydrodynamiques reposant sur la proportion du corps soumise aux ondulations motrices. L'etude biometrique (quatre mesures pour chaque vertebre) et histomorphometrique (compacite osseuse vertebrale) du rachis chez l'anguille, la truite, le chinchard et la bonite revelent une organisation particuliere et des caracteristiques structurales liees aux differents modes de nage qui se traduisent par une regionalisation du rachis en deux regions chez l'anguille et en trois regions chez les autres. L'emplacement des valeurs maxima des parametres vertebraux sur le rachis n'est pas le meme pour chaque modele. L'etude biometrique montre aussi un phenomene de croissance allometrique de certains secteurs vertebraux. La pertinence des descripteurs morphologiques est testee chez d'autres teleosteens avec un mode de nage axiale ou paraxiale grace a l'etude de leurs profils vertebraux et par une comparaison d'indices de position des maxima. Cet indice permet effectivement de regrouper dans un meme mode de nage certaines especes eventuellement issues de familles differentes, surtout dans le cas des modes de nage axiale. En revanche, pour des especes comme le brochet et pour les modes de nage paraxiale si certaines especes ont des caracteristiques morphologiques de leur rachis, il semble plus difficile pour d'autres d'utiliser les seuls resultats biometriques pour decrypter leur mode de nage

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Libri sul tema "Vertebrates Morphology"

International Symposium on Vertebrate Morphology (2nd 1986 Vienna, Austria). Tren ds in vertebrate morphology: Proceedings of the 2nd International Symposium on Vertebrate Morphology, Vienna, 1986. Stuttgart: G. Fischer Verlag, 1989.

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Vertebrate flight: Mechanics, physiology, morphology, ecology and evolution. Berlin: Springer-Verlag, 1990.

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Hildebrand, Milton. Analysis of vertebrate structure. 3^a ed. New York: Wiley, 1988.

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E, Goslow G., a cura di. Analysis of vertebrate structure. 5^a ed. New York: John Wiley, 2001.

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Hildebrand, Milton. Analysis of vertebrate structure. 4^a ed. New York: J. Wiley, 1995.

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What your fossils can tell you: Vertebrate morphology, pathology and cultural modification. Gainesville: University Press of Florida, 2010.

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Mossman, Harland W. Vertebrate fetal membranes: Comparative ontogeny and morphology ; evolution ; phytogenetic significance. New Brunswick, N. J: Rutgers University Press, 1987.

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Vertebral morphology, alternation of neural spine height, and structure in Permo-Carboniferous tetrapods, and a reappraisal of primitive modes of terrestrial locomotion. Berkeley: University of California Press, 1990.

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Vertebrate fetal membranes: Comparative ontogeny and morphology; evolution; phylogenetic significance; basic functions; research opportunities. Basingstoke: Macmillan, 1987.

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Mikhailov, K. E. Fossil and recent eggshell in amniotic vertebrates: Fine structure, comparative morphology and classification. London: The Palaeontological Association, 1997.

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Capitoli di libri sul tema "Vertebrates Morphology"

Gidmark, Nicholas J., Kelsie Pos, Bonne Matheson, Esai Ponce e Mark W. Westneat. "Functional Morphology and Biomechanics of Feeding in Fishes". In Feeding in Vertebrates, 297–332. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-13739-7_9.

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Brainerd, Elizabeth L., e Ariel L. Camp. "Functional Morphology of Vertebrate Feeding Systems: New Insights from XROMM and Fluoromicrometry". In Feeding in Vertebrates, 21–44. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-13739-7_2.

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Vinyard, Christopher J., Mark F. Teaford, Christine E. Wall e Andrea B. Taylor. "The Masticatory Apparatus of Humans (Homo sapiens): Evolution and Comparative Functional Morphology". In Feeding in Vertebrates, 831–65. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-13739-7_21.

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Weishampel, David B. "A Theoretical Morphological Approach to Tooth Replacement in Lower Vertebrates". In Constructional Morphology and Evolution, 295–310. Berlin, Heidelberg: Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/978-3-642-76156-0_20.

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Dodt, E. "Light Sensitivity of the Pineal Organ in Poikilothermic and Homeothermic Vertebrates". In Functional Morphology of Neuroendocrine Systems, 123–32. Berlin, Heidelberg: Springer Berlin Heidelberg, 1987. http://dx.doi.org/10.1007/978-3-642-72886-0_9.

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Rahmann, Hinrich, e Mathilde Rahmann. "Functional Morphology of the Nervous System in Vertebrates". In The Neurobiological Basis of Memory and Behavior, 45–91. New York, NY: Springer New York, 1992. http://dx.doi.org/10.1007/978-1-4612-2772-4_3.

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y Cajal, Santiago Ramón. "Morphology of the Nerve Cell (Continuation)". In Texture of the Nervous System of Man and the Vertebrates, 53–83. Vienna: Springer Vienna, 1999. http://dx.doi.org/10.1007/978-3-7091-6435-8_4.

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Reinecke, M., D. Betzler, H. Segner e W. G. Forssmann. "Dual distribution of cardiac hormones (CDD/ANP) in the heart and brain of vertebrates". In Functional Morphology of the Endocrine Heart, 87–93. Heidelberg: Steinkopff, 1989. http://dx.doi.org/10.1007/978-3-642-72432-9_9.

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Meisner, Donna Holmes. "Histology and Gross Morphology of the Sexually Dimorphic Sternal Gland in the North American Opossum, Didelphis Virginiana Kerr". In Chemical Signals in Vertebrates 4, 579–85. Boston, MA: Springer US, 1986. http://dx.doi.org/10.1007/978-1-4613-2235-1_46.

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y Cajal, Santiago Ramón. "Physiologic Inferences from the Morphology and Connectivity of Neurons". In Texture of the Nervous System of Man and the Vertebrates, 85–122. Vienna: Springer Vienna, 1999. http://dx.doi.org/10.1007/978-3-7091-6435-8_5.

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Atti di convegni sul tema "Vertebrates Morphology"

Chiesa, Elena, Paola Irato e Gianfranco Santovito. "THE CIRCULATORY SYSTEM OF VERTEBRATES AND INVERTEBRATES: AN EMPIRICAL RESEARCH TO INTRODUCE IN THE FOURTH CLASS THE TREATMENT OF ANIMAL MORPHOLOGY IN A COMPARATIVE KEY". In 13th International Technology, Education and Development Conference. IATED, 2019. http://dx.doi.org/10.21125/inted.2019.0391.

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Lim, Poay Hoon, Ulas Bagci, Omer Aras e Li Bai. "Identification of spinal vertebrae using mathematical morphology and level set method". In 2011 IEEE Nuclear Science Symposium and Medical Imaging Conference (2011 NSS/MIC). IEEE, 2011. http://dx.doi.org/10.1109/nssmic.2011.6152563.

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Kode, Swathi, Nicole A. Kallemeyn, Joseph D. Smucker, Douglas C. Fredericks e Nicole M. Grosland. "Adaptive Bone Remodeling Theory Applied to Cervical Laminoplasty". In ASME 2011 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2011. http://dx.doi.org/10.1115/sbc2011-53262.

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Abstract (sommario):

Laminoplasty, considered an alternative to laminectomy, is intended to relieve pressure on the spinal cord while maintaining the stabilizing effects of the posterior elements of the vertebrae. Open-door laminoplasty (ODL) includes opening of the lamina from either the left or right side with the contralateral side acting as hinge. The main aim of laminoplasty is to recreate a stable laminar arch that preserves laminar opening. As hinge failure is a commonly encountered problem during laminoplasty, it is necessary to understand the process of bone remodeling post laminoplasty. This study aims at implementing a computer simulation method to predict bone remodeling in accordance with Wolff’s Law. Mathematical models are based on the principle that bone remodeling is induced by a local mechanical signal that activates regulating cells to adapt accordingly by changing either the internal or external morphology [5].

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Thrane, Lars, Thomas M. Jørgensen e Jörg Männer. "Optical tissue clearing improves usability of optical coherence tomography (OCT) for high-throughput analysis of the internal structure and 3D morphology of small biological objects such as vertebrate embryos". In SPIE BiOS, a cura di Andrew M. Rollins, Cecilia W. Lo e Scott E. Fraser. SPIE, 2014. http://dx.doi.org/10.1117/12.2037303.

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